Hydrochemistry and carbonate sediment characterisation of ... · Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean Nidia I. Tobo´n Vela´zquezA,

Hydrochemistry and carbonate sediment characterisationof Bacalar Lagoon Mexican Caribbean

Nidia I Tobon VelazquezA Mario Rebolledo VieyraAC Adina PaytanBKyle H BroachB and Laura M Hernandez TerronesADE

ACentro de Investigacion Cientıfica de Yucatan Unidad Quintana Roo Unidad de Ciencias del

AguaCalle 839 Lote-1Manzana29 SuperManzana64 77524CancunQuintanaRooMexicoBInstitute of Marine Sciences Earth and Marine Science Building University of California Santa

Cruz 1156 High Street Santa Cruz CA 95064 USACPresent address Chipre 5 Residencial Isla Azul Cancun Quintana Roo 77500 MexicoDPresent address Universidad del Caribe Lote-1 Manzana 1 Esquina Fraccionamiento

Tabachines Super Manzana 78 CP 77528 Cancun Quintana Roo MexicoECorresponding author Email lmhernandezucaribeedumx

Abstract The aim of the study is to determine the distribution of trace and major elements in the water and in thesediments of the south part of the Bacalar Lagoon and to identify the sources of the trace elements and their changes overtime The western part of the lagoon water column is characterised by high concentrations of Ca2thorn HCO3

and Sr2thornderived from groundwater input In contrast the eastern part of the lagoon is characterised by high concentrations ofMg2thornNathorn and Cl The lagoon is not affected by present-day seawater intrusion Water column and sediment geochemicalanalyses performed in Bacalar Lagoon show clear spatial distribution of different parameters The saturation index of the

water column indicates three main groups (1) a zone oversaturated with regard to aragonite calcite and dolomite (2) anundersaturated area where all three minerals are dissolving and (3) an area with calcite equilibrium and undersaturationwith regard to the otherminerals Hereinwe present the first measurements of trace element (Ba2thornMn2thorn Kthorn Ni2thorn Zn2thorn)concentrations in carbonates obtained from sediments in Bacalar Lagoon In order to evaluate whether the trace elements

are derived from natural or anthropogenic sources four pollution indices were calculated The results confirmed thatBacalar Lagoon sediments are not contaminated with Ni2thorn Kthorn Mn2thorn and Ba2thorn and that the Zn2thorn seems to have apredominantly anthropogenic origin

Additional keywords carbonate mineral solubility groundwater sediment geochemistry

Received 15 February 2018 accepted 31 July 2018 published online 23 October 2018

Introduction

Surface and groundwater systems in the Mexican Caribbean arebeing affected by contaminants particularly heavy metals dueto poor or a lack of proper waste water treatment and an increasein activities related to growth in population tourism agriculture

and livestock (Dıaz 2005 Medina et al 2014 Ochoa et al

2016) The economy of Quintana Roo is based on tourism andits population has increased 17-fold over the past 40 years

(Dixon et al 2001 Bauer-Gottwein et al 2011 InstitutoNacional de Estadıstica y Geografıa 2016) This representssubstantial infrastructure needed for clean water supply and

waste water treatment and improperly functioning or non-existent infrastructure results in the discharge of waste waterinto surface waterbodies such as the coastal ocean and lagoons

(Hernandez-Terrones et al 2011) Moreover the karst nature ofthe area promotes waste water infiltration and mixing withgroundwater (Beddows 2002)

Bacalar Lagoon (south Quintana Roo) is a very popular place

for tourism Bacalar Lagoon is unique in the region due to thepresence of carbonate structures called stromatolites Thelagoonrsquos stromatolites are one of the largest freshwater micro-bialite occurrences in the world (10 km Gischler et al 2008

Centeno et al 2012) and preserve past information aboutclimatic and microbial life conditions and processes at the timeof sedimentation so it is important to ensure that these forma-

tions are not affected by water pollution The growth ofstromatolites depends on the physicochemical conditions ofthe water they are sensitive to changes in the environment

and any change in water quality could affect their development(Dupraz et al 2011) The main activities around the lagoon aretourism agriculture (sugarcane pineapple rice and maize)

livestock (cattle swine sheep) and aquaculture (InstitutoNacio-nal de Estadıstica y Geografıa 2002 Dıaz 2005) Bacalar townbecame a municipality in 2014 and is planning regulation to

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Marine and Freshwater Research

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ensure tourism activities will not stress the lagoonrsquos ecosystemhowever the lagoon has not been declared a protected area The

current lack of regulation for infrastructure and tourism mayresult in degradation of the water quality of the lagoon ecosys-tem structure and possibly the integrity of stromatolites (Dıaz

2005) Previous studies in Bacalar Lagoon provided physicalinformation about the lagoon but none focused on water qualityand sources of pollution (Dıaz 2005 Gischler et al 2008 2011

Perez et al 2011 Siqueiros-Beltrones et al 2013 Castro-Contreras et al 2014 Gonzalez et al 2014 Sanchez et al

2015 Oliva et al 2016)Pollution from trace elements may be of particular concern

Trace metals can occur as dissolved or colloidal phases or theymay be present in association with suspended particles in thewater column andwithin sedimentary phases (Katip et al 2011)

Many trace metals are present at higher concentrations insedimentary phases than in the water column (Nriagu andPacyna 1988 Pradit et al 2010) Trace metal concentrations

in the water are controlled by inputs from land through weath-ering processes groundwater discharge and atmospheric depo-sition (Salomons and Forstner 1980) as well as fromanthropogenic activities and each input can change over time

Therefore sediments (including stromatolite beds) can serve asarchives of environmental changes through time and changes inthe chemical composition of the sediments may be informative

of changes in natural and anthropogenic sources and fluxes oftrace metals (Boyle 2001) The chemical composition of sedi-ments and water can also be used to identify the rockndashwater

interaction and mineralogical composition of aquifer rocks(Elango and Kannan 2007)

Herein we report for the first time the distribution of trace

and major elements in the water column (along with hydrogra-phy) and in the sediments of the south part of the lagoon (near thelocation of the stromatolites) Through these analyses weidentify the sources of the trace elements and their changes over

time in Bacalar Lagoon

Materials and methods

Study area

Bacalar Lagoon is located in the south-eastern part of QuintanaRooMexico (from18856026500N 8889028600Wto18832038600N88827048600W) 15 m above sea level Fig 1) This area ischaracterised by a humid tropical climate with a mean annual airtemperature of 2608C Three meteorological seasons dominatethe region (1) the lsquonortesrsquo season between October and April

characterised by cold fronts (2) the dry season betweenApril andMay and (3) the wet season from June to October when tropicalstorms and hurricanes result in high rainfall The average annual

rainfall in the region ranges between 100 and 1500 mm year1with mean temperatures during winter and summer being280and2908C respectively (Comision Nacional del Agua 2015)

The lagoon has a surface area of 420 km2 (length 400 kmwidth10ndash20 km Comision Nacional del Agua 2002 Castro-Contreras et al 2014) It is an oligotrophic freshwater system

(electrical conductivity (EC) 23 mS cm1) and has a pHbetween 76 and 83 (Beltran 2010) The maximum water depthof the lagoon is 15 m but the water level of the lagoon canincrease by up to 300 cm during the wet season (Junendash

October Gischler et al 2011)

Bacalar Lagoon is situated in Hydrological Region number 33(RH33ComisionNacional del Agua 2012) Five sinkholes (locally

called cenotes) are located inside andnear the lagoon (Gischler et al2008) The cenotes Cocalitos Esmeralda and Negro are locatedinside the lagoon whereas cenote Azul (with a maximum water

depth of 900 m) is located outside the lagoon but has an under-ground connection to the lagoonCenoteXul-Ha is connected to thelagoon through a surface channel in the south-west area (Perry et al2009 Beltran 2010 Gischler et al 2011 Perez et al 2011)

The lagoon is located along the Bacalar fault system andsurrounding rocks are mostly from the Bacalar Formation thathave been assigned aNeogene age To the north the outcrops are

ofmarine Pliocene to Holocene age whereasMiocene age rocksare observed to the south Upper Cretaceous outcrops have alsobeen identified particularly along the west side of the lagoon

(Kenkmann and Schonian 2006) Based on Sr isotopes Perryet al (2009) suggest that in this region the slow-movinggroundwater derives its ion chemistry from relatively soluble

aquifer rocks including gypsum calcite dolomite and accessoryminerals such as celestite (SrSO4) Perry et al (2009) alsoobserved that water Sr isotope analyses of Bacalar Lagoonand cenote Azul suggest that these waterbodies derive their Sr

from dissolution of minerals of CretaceousndashEocene age

Field sampling

Seven sampling sites were selected along the southernmost

100 km of Bacalar Lagoon with five sites located on the

88270W

0 1 2 3 4 km05183

30

N18

36

0N

183

90

N18

42

0N

183

30

N18

36

0N

183

90

N18

42

0N

88240W 88210W

88270W 88240W 88210W

N

S

W E

Fig 1 Location of Bacalar Lagoon showing sampling sites Site details are

given in Table 1 BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz

cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los Rapidos

B Marine and Freshwater Research N I Tobon ndashVelazquez et al

western side of the lagoon and two located on the eastern side(Fig 1) Two sampling campaigns were performed The loca-

tions of the sites were determined using a global positioningsystem (GPS (NOMAD Trimble Sunnyvale CA USA) withtheWorld Geodetic System (WGS) 84 datum Temperature pH

depth total dissolved solids (TDS) EC and dissolved oxygen(DO) were measured in the field (during both samplingcampaigns) using a multiparameter sonde (Model 6600 YSI

Control Tecnico y Representaciones Mexico City Mexico)Temperature profile data were collected using a CastAway-CTD (SonTek Xylem San Diego CA USA) The field para-meters were measured as close to sediment core and water

sample collection points as possibleThe first sampling campaign was conducted in November

2016 Five sediment cores of variable length (between 11 and

41 cm) were collected using a steel push core with 50-cmdiameter plastic liners Three sediment cores were taken at thewestern side of the lagoon (COCRAPandBAC3) and two cores

were taken at the eastern side (BAC1 and BAC2 Fig 1) Thesamples were kept at 408C The sediment cores were sectionedinto 40-cm intervals for a total of 27 samples Samples weredried at 508C in an oven and powdered using an agate mortar and

pestle In addition surface water samples were collected at eachof the seven study sites (Fig 1) Allwater samples were collectedin acid-washed polyethylene bottles (Nalgene SigmandashAldrich

Mexico Toluca Mexico) rinsed with sample at the time ofcollection Samples were filtered using 045-mm syringe filtersand analysed for alkalinity nutrients cations and anions

The second sampling campaign was conducted in June 2017During this campaign water samples were taken from sites atcenote Azul (Caz) and cenote Cocalitos (Ccoc Fig 1) At each

site two water samples (surface and at a depth of 150 m) werecollected by divers All samples collected during both campaignswere kept at 408C and transported to the Hydrogeochemistryand Water Quality Laboratory of the Water Sciences Unit

Centro de Investigacion Cientıfica de Yucatan

Laboratory analysis

Alkalinity was measured by the titration method using 02 Nsulfuric acid (H2SO4) Nutrients (NO3

NO2 PO4

3) cations(Ca2thorn Nathorn Mg2thorn Kthorn Sr2thorn) and anions (Cl SO4

2) weredetermined using ion chromatography with an 882 CompactPlus ICMetrohm (MetrohmMexico Mexico City Mexico) andcertified standards (TraceCERT SigmandashAldrich Mexico) forcalibration For determination of NH4

thorn a spectrophotometer

(LaMotte Analisis y Soluciones Ambientales Mexico CityMexico) was used Water analyses were performed at theHydrogeochemistry andWater Quality Laboratory of theWater

Sciences Unit Centro de Investigacion Cientıfica de YucatanAC The concentrations of major elements (Al Fe Ca Mg TiSr and K) and trace elements (Mn Ba Ni Zn andU) in sediment

samples were determined after sample dissolution using induc-tively coupled plasmandashmass spectrometry (ICP-MS XRThermoScientific San Diego CA USA) at the Institute of Marine Sci-

ences at the University of California ndash Santa Cruz (UCSC) Priorto these analyses 100 mg of homogenised sediment was dis-persed in 15 mL ofMilliQwater and digested using 155 N nitricacid (HNO3

) A 100-mL subsample was diluted 200-fold using

1HNO3 for analysis Instrumental drift was corrected with Sc

and Rh standards Rhwas used as the internal standard correctionfor Sr Ba and U whereas Sc was used as the internal standard

correction for all other elements Counts per second values wereconverted to concentrations using a standard curve prepared froma homemade rendition of the NIST1D (National Institute of

Standards and Technology NIST) standard reference material(argillaceous limestone) An average of three procedural blankswas subtracted from final concentration values

To determine the sediment mineralogy sediment samples(20 g) were analysed using a Panalytical XrsquoPert Pro X-RayDiffraction (XRD) Spectrometer (Royston UK) with a 1-hrotating platter in the Marine Sciences Laboratory UCSC

Sample 2-theta peaks were identified using the PanalyticalSpectrometer mineral spectrum database as a reference Themost prominent peaks for all samples occurred near 2958with a

pair of peaks near 46 and 478

Results and discussion

Physicochemical parameters

The main physicochemical features of shallow water in BacalarLagoon are presented in Table 1 The low EC values (265ndash319 mS cm1) indicate a freshwater system with pH ranging

from 66 to 73 at the sampling sites (mean pHfrac14 705) Watertemperature was relatively stable in the study area during oursampling campaigns (275ndash2978C) The EC temperature andpH ranges measured in this study are consistent with measure-

mentsmade byGischler et al (2008) Beltran (2010) Perez et al(2011) Castro-Contreras et al (2014) and Sanchez et al (2015)in this system

Fig 2 shows the temperature profiles along the southern sideof Bacalar Lagoon The relatively small temperature variabilityamong lagoon sites (285ndash2888C) suggests a near-homoge-

neous temperature with depth for both seasons (Fig 2b) Thisindicates awell-mixedwater column consistentwith the shallowdepth of the lagoon where the samples were collected

In contrast the water column profiles of the cenotes show

slight variability between sampling campaigns in June thetemperature of cenotes Azul and Cocalitos was higher (310and 3048C respectively) compared with November tempera-

tures (3008C) During both sampling campaigns the cenotes

clearly show stratification with two thermoclines During Junethe cenote Azul thermoclines are at depths of 05 and 120 m

whereas in November they are at 23 and 290 m (Fig 2c) Atcenote Cocalitos the June thermoclines are at 38 and 290 mwhereas in November they are at 20 and 240 m (Fig 2d) For

both cenotes the first thermocline is related to diurnal changesin solar radiation (heating of surfacewaters) whereas the secondis derived from distinct mixing that varies seasonally andbetween years During winter (November) water column mix-

ing extends deeper due to wind action whereas during summer(June) the changes in thermocline depth are due to an increase intemperature over the warm months allowing for water column

stratification and shallowing of the thermoclineNO3

concentrations ranged from 01 to 27 mg L1whereas NO2

and PO43concentrations were below the limits

of detection of the method used in the present study (001 and01 mg L1 respectively) These results are consistent with theoligotrophic designation of Bacalar Lagoon It has been

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research C

suggested (Beltran 2010) that the low concentrations of bio-

available nitrogen (NH4thorn NO2

and NO3) promote N2 fixa-

tion in the lagoon The lower nutrient concentrations also favourthe growth of stromatolites (Beltran 2010)

Cation abundance in Bacalar Lagoon water follows the order

Ca2thornMg2thornNathorn Sr2thornKthorn anion abundance is in theorder SO4

2HCO3ClNO3

(see Table 1) In orderto determine the main hydrochemical features of the lagoon a

88200W882240W882520W88280W

88200W882240W882520W88280W

0 095 19 285 38 km

284 285 286 287 2880

5

10

15

20

25

30

285 295 305 315 26 27 28 29 30 31

Temperature (degC)

Dep

th (

m)

(b) (c) (d )

184

120

N18

38

40N

183

60

N18

33

20N

184

120

N18

38

40N

183

60

N18

33

20N

(a)

N

S

EW

Fig 2 Temperature profiles in the lagoon and cenotes (a) Sampling locations Each symbol corresponds to the traces shown in the graphs on the right (b)

Temperature profiles at the different study sites in Bacalar Lagoon (c d) Temperature profiles of cenote Azul (c) and cenote Cocalitos (d) Grey (dots and

diamonds) correspond to the November 2016 sampling campaign dashed lines correspond to the June 2017 sampling campaign

Table 1 Main physical and chemical parameters of water samples in Bacalar Lagoon

Standard deviation for the elements is as followsNathorn 097Kthorn 013Mg2thorn 298Ca2thorn 1429 Sr2thorn 034Cl 211 SO42 90 SiO2

26NO3

019 andNH4thorn 004BLD below the limit of detectionNA data not available Ionic balance10 The locations of each of the sample sites are shown in

Fig 1

COC RAP BAC1 BAC2 BAC3 Ccoc Caz

Site Cocalitos Los Rapidos Bacalar 1 Bacalar 2 Bacalar 3 Cenote Cocalitos Cenote Azul

Depth (m) 05 05 05 05 05 05 150 05 150

pH 658 697 731 734 NA 654 NA 685 NA

Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960

EC (mS cm1) 293 265 315 319 250 268 NA 267 NA

TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA

Chemical composition (mgL1)

Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360

Kthorn 075 041 180 174 025 358 297 282 305

Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810

Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650

Sr2thorn 546 631 715 439 270 476 592 545 552

Cl 10074 4166 28317 22640 4165 910 470 410 420

SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840

SiO2 1625 220 2225 2350 1575 320 300 360 310

HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410

NO3 140 174 268 010 267 20 128 255 283

NO2 BLD BLD BLD BLD BLD BLD BLD BLD BLD

NH4thorn 018 013 028 019 014 020 026 021 023

PO43 BLD BLD BLD BLD BLD BLD BLD BLD BLD

D Marine and Freshwater Research N I Tobon ndashVelazquez et al

Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together

in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva

et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy

sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared

with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the

southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most

important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of

Bacalar Lagoon is dominated by sulfates (9620ndash

11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold

greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high

sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group

spatial differences are present within the lagoon and may

suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The

western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L

1 and3760ndash4220 mg L1 respectively) compared with the eastern

side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)

The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1

respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient

indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the

contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity

The concentrations of Ca2thorn and SO42 are lower on the

eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4

2 are present To reach

the saturation necessary for precipitation of microbialites Ca2thorn

and SO42 are needed which has been reported in other systems

(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn

(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur

because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified

high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-

ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3

) to (NathornthornClthorn SO42) ratio

has been used to determine the effect of carbonate and evaporite

solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of

evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon

The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature

measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies

equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)

According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group

(Coc and Ccoc surface sample) all the minerals are

C a t i o n s A n i o n s mEq L1

NaK HCO3CO3 Cl

Mg SO4

CaCalcium (Ca) Chloride (Cl)

(SO 4

) (C

l)

(Ca)

(Mg)

(CO 3

)(H

CO 3

)

(Na)

(K)

Sulfate (SO4 )

Mag

nesi

um (M

g)

80 60 40 20 20 40 60 80

8060

4020

20

40

60

80

2040

6080

80

60

40

20

2040

6080

20

40

60

80

80

60

4020

8060

4020

COCRAPBAC1BAC2BAC3CcocCaz

Fig 3 Piper diagram and groundwater composition Each symbol corre-

spond to lagoon sites white square and white triangle points correspond to

cenotes samples which represent the groundwater in the region BAC1

Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc

cenote Cocalitos COC Cocalitos RAP Los Rapidos

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E

experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium

and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the

dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4

2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar

Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that

gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche

The Sr2thorn concentrations in samples from the western side are

quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared

concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon

to those of cenote AzulStandardised principal component analysis (PCA) was per-

formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-

perature pH EC TDS SiO2 HCO3

Cl SO42 NO3

NH4

thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47

and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among

COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast

Sat

urat

ion

inde

x

15

10

05

0

05

10

Anhydrite (CaSO4)Aragonite (CaCO3)

Calcite (CaCO3)

Celestite (SrSO4)Gypsum (CaSO42H2O)

Dolomite (Ca Mg(CO3))

Fig 5 Saturation index (SI) calculated for each sample site for all relevant

minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0

indicates oversaturation and SI 0 indicates undersaturation Asterisks

indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1

BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote

Cocalitos COC Cocalitos RAP Los Rapidos

24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K

Fig 6 Principal component analysis based on 15 chemical variables (grey

arrows) at different sampling sites (lagoon and cenotes) PC1 principal

component 1 PC2 principal component 2 EC electrical conductivity

TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2

Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos

COC Cocalitos RAP Los Rapidos

Table 2 Eigenvalues of principal component analysis components and

variance explained

Principal component Eigenvalue Variance explained ()

1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4

Conductivity (mS cm1)

Effect ofcarbonates

Fig 4 Mineralisation effect on water chemistry Dark grey points repre-

sent the sampling sites dashed circular areas indicate the range in which the

electrical conductivity and major element ratios are interpreted as resulting

from mineralisation of evaporites or carbonates according to Khedidja and

Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3

Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los

Rapidos

F Marine and Freshwater Research N I Tobon ndashVelazquez et al

samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence

variations could be interpreted as significant differencesbetween sites

Samples along PCA Axis 1 show two distinctive patterns

within the lagoon which are separated by pH EC TDS Nathorn

and HCO3 distribution The spread of samples within PC1 is

relatively large suggesting significant differences among sites

This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3

content (COC RAP BAC3 Ccoc and Caz) whereas the eastern

side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites

PC2 is associated with SiO2 and Kthorn concentrations PC2

shows two groups with the first group corresponding to sampleswith low SiO2

and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)

The second group is characterised by high SiO2 and Kthorn

concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes

compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant

Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be

associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be

established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected

Sediment characterisation

X-Ray diffraction

The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-

bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions

These results are in accordance with the SI where calcite is

oversaturated in the western part of the lagoon and Ca2thorn andHCO3

concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa

Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of

its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta

deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other

minerals that we found in lower proportions are barite (BaSO4)

and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon

Geochemistry

Elemental concentrations in the sediment samples are shown

in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-

tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in

the western part of the lagoon (COC RAP and BAC3) in the

order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn

KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was

similar except that Mg was more abundant than Ca (Mg2thorn

Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn

Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn

carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent

anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores

In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest

temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)

The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA

(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005

Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest

correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash

(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four

elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived

from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of

particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations

are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the

same parameters at each site

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G

Sediment pollution

Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices

followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic

element and is resistant to chemical weathering hence it does

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000

Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)

8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000

Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)

Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)

10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2

Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3

COC Cocalitos

H Marine and Freshwater Research N I Tobon ndashVelazquez et al

not actively participate in the dominant geochemical cycles and

does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)

For normalisation to Al values for the Earthrsquos crust were

taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm

Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or

anthropogenic sources the trace element concentrations were

compared with the crustal composition (Hernandez et al 2003)

frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN

frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN

where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the

average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input

The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are

lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices

also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted

conditions In contrast the values of these indices for Zn2thorn

and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples

(BAC1 and BAC2) show higher CD values (822 and 1805

respectively) suggesting moderate to considerable contamina-

tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and

the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are

unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core

samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a

higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to

confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)

and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn

and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically

and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town

of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more

than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and

Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area

Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)

Ms sample element concentration Mb background concentration of the element

Index Equation Sediment quality

Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted

0ndash1frac14 unpolluted to moderately polluted

1ndash2frac14moderately polluted

2ndash3frac14moderately polluted to highly polluted

3ndash4frac14 highly polluted

4ndash5frac14 highly polluted to very highly polluted

5frac14 very highly polluted

Contamination factor CF5MsMb 1frac14 low CF

1 CF 3frac14moderate CF

3 CF 6frac14 considerable CF

$6frac14 very high CF

Contamination degree CD frac14Pnifrac141

CF 6frac14 low CD

6 CD 12frac14moderate CD

12 CD 24frac14 considerable CD

$24frac14 high CD (anthropogenic contamination)

Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted

1frac14 baseline levels of pollutants present

1frac14 progressive deterioration of site

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I

Table4

Index

ofgeoacummulation(Igeo)anthropogenic(A

)inputcontaminationfactor(C

F)andcontaminationdegree(C

D)forBaUKMnNiandZnin

thesedim

entary

record

ofthe

BacalarLagoon

NAdatanoavailablePLIpollutionload

indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar

3COCCocalitosRAPLosRapidos

Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002

J Marine and Freshwater Research N I Tobon ndashVelazquez et al

in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these

products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of

Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in

the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores

Minimal trace metal pollution is consistent with previous

metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-

127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities

Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides

(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013

Buenfil-Rojas et al 2015)

Conclusions

Bacalar Lagoon is a shallow and oligotrophic system (low-

nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different

parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards

the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high

evaporation and high electrical conductivity compared with thewestern side

We present the first measurements of trace elements in

carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-

sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon

Conflicts of interest

The authors declare that they have no conflicts of interest

Declaration of funding

This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo

(282240) The authors acknowledge a grant from CONACYT

towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)

Acknowledgements

The authors thank technical staff Daniela Ortega (Water Sciences Unit

Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf

(University of CaliforniamdashSanta Cruz)

References

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(Springer-Verlag Berlin Germany)

Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-

gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo

(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)

pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)

Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and

Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)

Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols

(France) References et strategies drsquointerpretationrsquo (INRA Paris France)

Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M

andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer

Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-

0699-5

Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst

Groundwater System of the Municipalidad de Solidaridad Quintana

Roo Mexicorsquo (Association for Mexican Cave Studies Houston

TX USA)

Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y

diversidad asociada (nifH) en tapices microbianos y estromatolitos

MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de

Mexico Mexico

Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)

Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to

study anthropogenic element enrichments in lake sediments Journal of

Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z

Boyle J F (2001) Inorganic geochemical methods in paleolimnology In

lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-

cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash

143 (Kluwer Academic Publishers Dordrecht Netherlands)

Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R

(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile

moreletii) from a Transboundary River between Mexico and Belize

Archives of Environmental Contamination and Toxicology 68(2) 265ndash

273 doi101007S00244-014-0088-5

Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D

Castro C S Gregory D Planavsky N and Konhauser K O (2014)

Textural and geochemical features of freshwater microbialites from

LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10

2110PALO2013063

Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema

lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al

manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo

(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp

17ndash22 (Universidad de Quintana Roo Chetumal Mexico)

Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U

Ashby N M and Falcon I L (2012) Microbialite genetic diversity

and composition relate to environmental variables FEMSMicrobiology

Ecology 82 724ndash735 doi101111J1574-6941201201447X

Chagas A P Webb E G Burne V R and Southam G (2016) Modern

lacustrine microbialites towards a synthesis of aqueous and carbonate

geochemistry and mineralogy Earth-Science Reviews 162 338ndash363

doi101016JEARSCIREV201609012

Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-

chlorine pesticides in nest substratum and infertile eggs of American

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K

crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll

Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2

Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de

agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-

AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)

Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision

2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo

1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico

City Mexico)

Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad

media anual de agua en el acuıfero Cerros y Valles (2301) Estado de

QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de

Mexico Mexico)

Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources

distribution and behavior of major and trace elements in a complex karst

lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-

013-9204-9

Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de

ordenamiento ecologico territorial de la region de Laguna Bacalar

Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)

Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and

environment in the Caribbean an economic framework (The World

Bank Washington DC USA) Available at httpdocumentsworldbank

orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18

October 2018]

Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo

(Elsevier Oxford UK)

Drucker A Escalante R Gomez V and Magana S (2003) La industria

porcina en Yucatan un analisis de la generacion de aguas residuales

Problemas del Desarrollo Revista Latinoamericana de Economıa 34

(135) 105ndash120

Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In

lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo

(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg

Germany)

Elango L andKannan R (2007) Rockndashwater interaction and its control on

chemical composition of groundwater In lsquoDevelopments in Environ-

mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp

229ndash243 (Elsevier Oxford UK)

Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)

Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el

municipio deOthon P Blanco enQuintanaRoo y su potencial influencia

en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo

costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds

F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp


Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C

Wachtman J R Grajales J M Claeys P and Fischer G A (2002)

Cathodoluminescence petrography and isotope geochemistry of KT

impact ejecta deposited 360 km from the Chicxulub crater at Albion

Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091

200200435X

Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales

pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la

acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In

lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de

Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero

Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de

Quintana Roo Chetumal Mexico)

Gischler E Gibson M A and Oschmann W (2008) Giant Holocene

freshwater microbialites Laguna de Bacalar Quintana Roo Mexico

Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X

Gischler E Golubic S Gibson M Oschamann W and Hudson J H

(2011) Microbial mats and microbialites in the freshwater Laguna

Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite

Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)

pp 187ndash205 (Springer Berlin Germany)

Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O

Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg

Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la

region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23

Hemley R J Prewitt C T and Kingma K (1994) High-pressure

behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and

Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J

Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical

Society of America Washington DC USA)

Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal

distribution in some French forest soils evidence for atmospheric

contamination The Science of the Total Environment 312(1ndash3)

195ndash219 doi101016S0048-9697(03)00223-7

Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto

M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution

in a karstic region (NE Yucatan) baseline nutrient content and flux to

coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528

doi101007S11270-010-0664-X

InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del

Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at

httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv

contenidosespanolbvinegiproductoshistoricos2104702825224196

702825224196_1pdf [Verified 5 September 2018]

Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y

Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-

able at httpinternetcontenidosinegiorgmxcontenidosProductos

prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_

2016702825084370pdf [Verified 5 September 2018]

Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)

Fractionation of heavy metals in bottom sediments in Chahnimeh 1

Zabol Iran Environmental Monitoring and Assessment 187(6) 340

doi101007S10661-015-4510-X

Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S

(2011) Analysis and assessment of trace elements pollution in sediments

of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968

Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters

on Earth provide insights for Martian ejecta blankets Meteoritics amp

Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006

TB00437X

Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de

Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28

181ndash197

Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de

alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados

de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas

17(2) 137ndash141

Manoj K and Padhy P K (2014) Distribution enrichment and ecological

risk assessment of six elements in bed sediments of a tropical river

Chottanagpur Plateau a spatial and temporal appraisal Journal of

Environmental Protection 5 1419ndash1434 doi104236JEP2014514136

Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F

(2004) Isotopic and geochemical evolution of ground and surfacewaters

in a karst dominated geological setting a case study fromBelize Central

America Applied Geochemistry 19 937ndash946 doi101016JAPGEO

CHEM200310013

Massaferro J Correa M A Montes de Oca F and Mauad M (2018)

Contrasting responses of lake ecosystems to environmental disturbance

a paleoecological perspective from northern Patagonia (Argentina)

Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3

Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)

Hydrocarbon pollution studies of underwater sinkholes along Quintana

L Marine and Freshwater Research N I Tobon ndashVelazquez et al

Roo as function of tourism development in the Mexican Caribbean

Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516

Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot

G (1998) Hydrocarbon and organochloride residue concentrations in

sediments from Bay of Chetumal Mexico Bulletin of Environmental

Contamination and Toxicology 61 80ndash87 doi101007S001289900732

Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide

contamination of air water and soils by trace metals Nature 333 134ndash

139 doi101038333134A0

Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados

(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal

Revista Mexicana de Agroecosistemas 3(2) 263ndash271

Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A

(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)

en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa

Tropical 64(4) 1643ndash1650

Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B

Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-

neralization processes in freshwater stromatolites a living example from

eastern Patagonia International Association of Sedimentologists Jour-

nal 1(2) 130ndash146

Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P

Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the

Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia

661 407ndash433 doi101007S10750-010-0552-9

Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-

istry of the karst aquifer system of the northern Yucatan Peninsula

Mexico International Geology Review 44 191ndash221 doi102747

0020-6814443191

Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-

water geochemistry of the Yucatan Peninsula Mexico constraints on

stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40

doi101016JJHYDROL200812026

Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-

makers M (2010) Distribution of trace elements in sediments and biota

of Songkhla Lake Southern Thailand Water Air and Soil Pollution

206 155ndash174 doi101007S11270-009-0093-X

Salomons W and Forstner U (1980) Trace metal analysis on polluted

sediments II evaluation of environmental impact Environmental

Technology Letters 1 506ndash517 doi10108009593338009384007

Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo

B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas

del sur del Estado de Quintana Roo Mexico Revista Mexicana de

Ciencias Geologicas 32(1) 62ndash76

Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J

Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B

(2002) Hydrogeochemical and biological characteristics of cenotes in

the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228

doi101023A1014923217206

Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)

Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la

laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-

sidad 84 865ndash875 doi107550RMB33960

Turekian K K andWedepohl K H (1961) Distribution of the elements in

some major units of the Earthrsquos crust Bulletin of the Geological Society

of America 72 175ndash192 doi1011300016-7606(1961)72[175

DOTEIS]20CO2

Handling Editor Russell Frew

wwwpublishcsiroaujournalsmfr

Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M

ensure tourism activities will not stress the lagoonrsquos ecosystemhowever the lagoon has not been declared a protected area The

current lack of regulation for infrastructure and tourism mayresult in degradation of the water quality of the lagoon ecosys-tem structure and possibly the integrity of stromatolites (Dıaz

2005) Previous studies in Bacalar Lagoon provided physicalinformation about the lagoon but none focused on water qualityand sources of pollution (Dıaz 2005 Gischler et al 2008 2011

Perez et al 2011 Siqueiros-Beltrones et al 2013 Castro-Contreras et al 2014 Gonzalez et al 2014 Sanchez et al

2015 Oliva et al 2016)Pollution from trace elements may be of particular concern

Trace metals can occur as dissolved or colloidal phases or theymay be present in association with suspended particles in thewater column andwithin sedimentary phases (Katip et al 2011)

Many trace metals are present at higher concentrations insedimentary phases than in the water column (Nriagu andPacyna 1988 Pradit et al 2010) Trace metal concentrations

in the water are controlled by inputs from land through weath-ering processes groundwater discharge and atmospheric depo-sition (Salomons and Forstner 1980) as well as fromanthropogenic activities and each input can change over time

Therefore sediments (including stromatolite beds) can serve asarchives of environmental changes through time and changes inthe chemical composition of the sediments may be informative

of changes in natural and anthropogenic sources and fluxes oftrace metals (Boyle 2001) The chemical composition of sedi-ments and water can also be used to identify the rockndashwater

interaction and mineralogical composition of aquifer rocks(Elango and Kannan 2007)

Herein we report for the first time the distribution of trace

and major elements in the water column (along with hydrogra-phy) and in the sediments of the south part of the lagoon (near thelocation of the stromatolites) Through these analyses weidentify the sources of the trace elements and their changes over

time in Bacalar Lagoon

Materials and methods

Study area

Bacalar Lagoon is located in the south-eastern part of QuintanaRooMexico (from18856026500N 8889028600Wto18832038600N88827048600W) 15 m above sea level Fig 1) This area ischaracterised by a humid tropical climate with a mean annual airtemperature of 2608C Three meteorological seasons dominatethe region (1) the lsquonortesrsquo season between October and April

characterised by cold fronts (2) the dry season betweenApril andMay and (3) the wet season from June to October when tropicalstorms and hurricanes result in high rainfall The average annual

rainfall in the region ranges between 100 and 1500 mm year1with mean temperatures during winter and summer being280and2908C respectively (Comision Nacional del Agua 2015)

The lagoon has a surface area of 420 km2 (length 400 kmwidth10ndash20 km Comision Nacional del Agua 2002 Castro-Contreras et al 2014) It is an oligotrophic freshwater system

(electrical conductivity (EC) 23 mS cm1) and has a pHbetween 76 and 83 (Beltran 2010) The maximum water depthof the lagoon is 15 m but the water level of the lagoon canincrease by up to 300 cm during the wet season (Junendash

October Gischler et al 2011)

Bacalar Lagoon is situated in Hydrological Region number 33(RH33ComisionNacional del Agua 2012) Five sinkholes (locally

called cenotes) are located inside andnear the lagoon (Gischler et al2008) The cenotes Cocalitos Esmeralda and Negro are locatedinside the lagoon whereas cenote Azul (with a maximum water

depth of 900 m) is located outside the lagoon but has an under-ground connection to the lagoonCenoteXul-Ha is connected to thelagoon through a surface channel in the south-west area (Perry et al2009 Beltran 2010 Gischler et al 2011 Perez et al 2011)

The lagoon is located along the Bacalar fault system andsurrounding rocks are mostly from the Bacalar Formation thathave been assigned aNeogene age To the north the outcrops are

ofmarine Pliocene to Holocene age whereasMiocene age rocksare observed to the south Upper Cretaceous outcrops have alsobeen identified particularly along the west side of the lagoon

(Kenkmann and Schonian 2006) Based on Sr isotopes Perryet al (2009) suggest that in this region the slow-movinggroundwater derives its ion chemistry from relatively soluble

aquifer rocks including gypsum calcite dolomite and accessoryminerals such as celestite (SrSO4) Perry et al (2009) alsoobserved that water Sr isotope analyses of Bacalar Lagoonand cenote Azul suggest that these waterbodies derive their Sr

from dissolution of minerals of CretaceousndashEocene age

Field sampling

Seven sampling sites were selected along the southernmost

100 km of Bacalar Lagoon with five sites located on the

88270W

0 1 2 3 4 km05183

30

N18

36

0N

183

90

N18

42

0N

183

30

N18

36

0N

183

90

N18

42

0N

88240W 88210W

88270W 88240W 88210W

N

S

W E

Fig 1 Location of Bacalar Lagoon showing sampling sites Site details are

given in Table 1 BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz

cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los Rapidos

B Marine and Freshwater Research N I Tobon ndashVelazquez et al














Laboratory analysis


NO2 PO4









































2HCO3ClNO3


88200W882240W882520W88280W

88200W882240W882520W88280W

0 095 19 285 38 km

284 285 286 287 2880

5

10

15

20

25

30

285 295 305 315 26 27 28 29 30 31

Temperature (degC)

Dep

th (

m)

(b) (c) (d )

184

120

N18

38

40N

183

60

N18

33

20N

184

120

N18

38

40N

183

60

N18

33

20N

(a)

N

S

EW






26NO3


Fig 1



Depth (m) 05 05 05 05 05 05 150 05 150

pH 658 697 731 734 NA 654 NA 685 NA

Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960

EC (mS cm1) 293 265 315 319 250 268 NA 267 NA

TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA


Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360

Kthorn 075 041 180 174 025 358 297 282 305

Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810

Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650

Sr2thorn 546 631 715 439 270 476 592 545 552

Cl 10074 4166 28317 22640 4165 910 470 410 420

SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840

SiO2 1625 220 2225 2350 1575 320 300 360 310

HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410

NO3 140 174 268 010 267 20 128 255 283


NH4thorn 018 013 028 019 014 020 026 021 023











































NaK HCO3CO3 Cl

Mg SO4


(SO 4

) (C

l)

(Ca)

(Mg)

(CO 3

)(H

CO 3

)

(Na)

(K)

Sulfate (SO4 )

Mag

nesi

um (M

g)

80 60 40 20 20 40 60 80

8060

4020

20

40

60

80

2040

6080

80

60

40

20

2040

6080

20

40

60

80

80

60

4020

8060

4020




















Cl SO42 NO3

NH4




Sat

urat

ion

inde

x

15

10

05

0

05

10


Calcite (CaCO3)









24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K








variance explained


1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4


Effect ofcarbonates







Rapidos





















X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2

















Laboratory analysis


NO2 PO4









































2HCO3ClNO3


88200W882240W882520W88280W

88200W882240W882520W88280W

0 095 19 285 38 km

284 285 286 287 2880

5

10

15

20

25

30

285 295 305 315 26 27 28 29 30 31

Temperature (degC)

Dep

th (

m)

(b) (c) (d )

184

120

N18

38

40N

183

60

N18

33

20N

184

120

N18

38

40N

183

60

N18

33

20N

(a)

N

S

EW






26NO3


Fig 1



Depth (m) 05 05 05 05 05 05 150 05 150

pH 658 697 731 734 NA 654 NA 685 NA

Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960

EC (mS cm1) 293 265 315 319 250 268 NA 267 NA

TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA


Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360

Kthorn 075 041 180 174 025 358 297 282 305

Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810

Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650

Sr2thorn 546 631 715 439 270 476 592 545 552

Cl 10074 4166 28317 22640 4165 910 470 410 420

SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840

SiO2 1625 220 2225 2350 1575 320 300 360 310

HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410

NO3 140 174 268 010 267 20 128 255 283


NH4thorn 018 013 028 019 014 020 026 021 023











































NaK HCO3CO3 Cl

Mg SO4


(SO 4

) (C

l)

(Ca)

(Mg)

(CO 3

)(H

CO 3

)

(Na)

(K)

Sulfate (SO4 )

Mag

nesi

um (M

g)

80 60 40 20 20 40 60 80

8060

4020

20

40

60

80

2040

6080

80

60

40

20

2040

6080

20

40

60

80

80

60

4020

8060

4020




















Cl SO42 NO3

NH4




Sat

urat

ion

inde

x

15

10

05

0

05

10


Calcite (CaCO3)









24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K








variance explained


1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4


Effect ofcarbonates







Rapidos





















X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2










2HCO3ClNO3


88200W882240W882520W88280W

88200W882240W882520W88280W

0 095 19 285 38 km

284 285 286 287 2880

5

10

15

20

25

30

285 295 305 315 26 27 28 29 30 31

Temperature (degC)

Dep

th (

m)

(b) (c) (d )

184

120

N18

38

40N

183

60

N18

33

20N

184

120

N18

38

40N

183

60

N18

33

20N

(a)

N

S

EW






26NO3


Fig 1



Depth (m) 05 05 05 05 05 05 150 05 150

pH 658 697 731 734 NA 654 NA 685 NA

Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960

EC (mS cm1) 293 265 315 319 250 268 NA 267 NA

TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA


Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360

Kthorn 075 041 180 174 025 358 297 282 305

Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810

Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650

Sr2thorn 546 631 715 439 270 476 592 545 552

Cl 10074 4166 28317 22640 4165 910 470 410 420

SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840

SiO2 1625 220 2225 2350 1575 320 300 360 310

HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410

NO3 140 174 268 010 267 20 128 255 283


NH4thorn 018 013 028 019 014 020 026 021 023











































NaK HCO3CO3 Cl

Mg SO4


(SO 4

) (C

l)

(Ca)

(Mg)

(CO 3

)(H

CO 3

)

(Na)

(K)

Sulfate (SO4 )

Mag

nesi

um (M

g)

80 60 40 20 20 40 60 80

8060

4020

20

40

60

80

2040

6080

80

60

40

20

2040

6080

20

40

60

80

80

60

4020

8060

4020




















Cl SO42 NO3

NH4




Sat

urat

ion

inde

x

15

10

05

0

05

10


Calcite (CaCO3)









24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K








variance explained


1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4


Effect ofcarbonates







Rapidos





















X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2












































NaK HCO3CO3 Cl

Mg SO4


(SO 4

) (C

l)

(Ca)

(Mg)

(CO 3

)(H

CO 3

)

(Na)

(K)

Sulfate (SO4 )

Mag

nesi

um (M

g)

80 60 40 20 20 40 60 80

8060

4020

20

40

60

80

2040

6080

80

60

40

20

2040

6080

20

40

60

80

80

60

4020

8060

4020




















Cl SO42 NO3

NH4




Sat

urat

ion

inde

x

15

10

05

0

05

10


Calcite (CaCO3)









24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K








variance explained


1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4


Effect ofcarbonates







Rapidos





















X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2
















Cl SO42 NO3

NH4




Sat

urat

ion

inde

x

15

10

05

0

05

10


Calcite (CaCO3)









24

2

4

0

2

4

0

PC1

2 4

PC

2

Ca

pHSO4

HCO3

NO3

Temp

TDS

Mg

ECNaCl

Sr

NH4

Caz

Ccoc

BAC2 BAC1

RAP

BAC3

COC

SiO2SiO2

K








variance explained


1 706 4712

2 338 2258

3 210 1402

4 127 851

0 05 10 15 20 25 30 3502

04

06

10

12

14

Effect ofevaporates

BAC3

RAP

COCCaz

CcocBAC2

BAC1

Ca

Mg

HC

O3

Na

Cl

SO

4


Effect ofcarbonates







Rapidos





















X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2























X-Ray diffraction











Geochemistry

























Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2




Sediment pollution




50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

50

40

30

20

10

0

8000 9000 10 000 11 000


8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000

Dep

th (

cm)

0 1000 5000



10 000 2020 000 2001000 0 200 000 400 000

0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080

COC BAC3 BAC1 BAC2


COC Cocalitos















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2

















































CF 6frac14 low CD








Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2




Table4

Index





thesedim

entary

record

ofthe

BacalarLagoon


indexBAC1Bacalar

1BAC2Bacalar

2BAC3Bacalar


Site

Depth

(cm)

Ba

UK

Mn

Ni

Zn

PLI

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

I geo

Ainput

CF

CD

COC

0ndash6

016

1236

134

701

503

013

005

065

688

24629

001

003

1119

11361

0001

0002

371

021

011

053

203

529

037

479

005

6ndash12

015

1314

135

469

005

006

675

5569

001

1160

3753

0000

409

107

009

004

2846

146

006

12ndash17

004

1421

146

336

024

015

NA

10001

000

1147

4016

0001

405

107

009

037

2254

116

000

17ndash22

014

1627

165

304

035

018

1158

6288

000

1257

2588

0000

362

196

012

010

3174

161

004

22ndash27

031

1156

121

282

035

021

NA

14125

000

1338

5739

0000

367

132

012

301

267

019

000

RAP

0ndash6

039

1074

115

264

538

008

004

009

889

18818

000

002

1067

7912

0001

0001

508

057

004

014

156

870

051

284

004

6ndash11

001

1360

149

475

017

006

651

31721

002

1189

14691

0000

391

069

010

063

4390

233

007

BAC1

0ndash5

024

267

127

956

402

201

009

069

230

189364

031

161

896

110398

0003

0023

300

1639

019

115

174

1118

045

822

014

5ndash10

035

302

118

416

174

008

276

176636

022

907

96021

0003

311

1404

017

066

2982

237

017

10ndash15

048

382

108

437

137

007

307

139830

018

913

76341

0003

327

1083

016

119

074

066

013

15ndash20

031

444

121

423

150

008

295

153179

019

896

83486

0003

330

1220

015

013

1225

137

015

20ndash25

031

488

121

420

142

008

301

145741

019

883

79449

0003

351

1189

013

424

1293

008

009

25ndash30

039

504

114

408

121

009

320

128917

016

925

70152

0002

363

1037

012

061

689

098

013

30ndash35

016

581

134

385

145

010

299

154625

019

904

83454

0003

353

1264

013

069

337

093

014

35ndash40

041

467

113

419

127

008

313

131772

017

917

72183

0003

392

1120

010

012

1446

138

013

BAC2

0ndash6

035

1141

117

734

515

002

004

086

743

6689

001

006

1094

3596

0001

0006

374

157

011

444

051

4203

214

1805

007

6ndash11

052

1005

105

462

004

006

834

10694

000

949

4638

0002

119

6764

343

012

2666

138

012

11ndash16

055

984

103

442

006

007

750

9268

001

1126

4617

0001

420

078

008

144

1018

055

005

16ndash21

055

985

102

400

013

009

597

3426

002

1119

3962

0001

421

089

008

001

2953

151

008

21ndash26

043

1093

111

296

038

019

828

3839

000

1178

2046

0000

412

135

009

293

22785

1141

009

26ndash31

068

925

094

254

054

026

832

2578

000

1194

1524

0000

273

424

023

104

1434

073

006

36ndash41

056

1001

102

337

028

014

875

3556

000

1113

1759

0001

182

819

043

219

626

033

006

BAC3

0ndash6

016

1283

134

407

607

009

002

007

682

12943

001

002

1266

6706

0000

0001

553

057

003

008

211

572

035

152

003

6ndash12

020

1270

131

607

003

002

989

9545

000

1308

4043

0000

580

020

003

081

1639

086

002

12ndash18

008

1389

142

613

003

002

891

8695

000

1341

3872

0000

593

021

002

223

567

032

002












Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2














Conclusions















Acknowledgements




References














0699-5




TX USA)




Mexico Mexico













273 doi101007S00244-014-0088-5





2110PALO2013063

























City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2












City Mexico)




Mexico Mexico)




013-9204-9








October 2018]






(135) 105ndash120




Germany)

















200200435X




























195ndash219 doi101016S0048-9697(03)00223-7





doi101007S11270-010-0664-X














doi101007S10661-015-4510-X







TB00437X



181ndash197




17(2) 137ndash141









CHEM200310013
















139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2












139 doi101038333134A0
















661 407ndash433 doi101007S10750-010-0552-9




0020-6814443191








206 155ndash174 doi101007S11270-009-0093-X












doi101023A1014923217206








DOTEIS]20CO2




Hydrochemistry and carbonate sediment characterisation of ... · Hydrochemistry and carbonate sediment characterisation of Bacalar Lagoon, Mexican Caribbean Nidia I. Tobo´n Vela´zquezA,

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