New insight on the geology of the Kuwait Group- Jal Al-Zoor Escarpment- Sabah Al Ahmad Natural Reserve, Kuwait Alham Al-langawi PAAET- Science Department.

New insight on the geology of the Kuwait Group- Jal Al-Zoor

Escarpment- Sabah Al Ahmad Natural Reserve, Kuwait

Alham Al-langawiPAAET- Science Department

College of Basic Education- Kuwait

This Research was based onThis Research was based on

Fieldwork investigations and samplingFieldwork investigations and sampling Petrographic study by polarizing Petrographic study by polarizing

microscope and SEMmicroscope and SEM CathodoluminecenceCathodoluminecence XRFXRF IcpmsIcpms Probe analysisProbe analysis Carbone and oxygen isotope analysisCarbone and oxygen isotope analysis

Geology Of Kuwait For Jal Azoor Geology Of Kuwait For Jal Azoor Escarpment based on Previous StudiesEscarpment based on Previous Studies

Age Group Formation Description

Holocene

Include marine beach deposits,sabkha and mud flatssediments, alluvial and fluvialsediments

Pleistocene

KuwaitGroup

DibdibbaConglomerates, gypsum cements

Lower-MiddleMiocene

LowerFars

Calcareous fine sandstones, Coarsesandstones, marly limestones, redand green mudstones, sandyLimestones (30-35 m)

LowerMiocene-Oligocene

GharCoarse Quartz Arenites, sandylimestones, marls and greenMudstones (only 20 m exposed)

Eocene Alhassa DammamDolomitized limestones withChirt

Disconformity

Disconformity

Disconformity

Upper Miocene & Pliocene 8.6 Ma ?

Flu

vial

Mar

ine

Field ObservationsField Observations

Disconformity between Disconformity between first (Dibdibba Fm.) and first (Dibdibba Fm.) and second (lower Fars Fm.)second (lower Fars Fm.)

Sharp Contact

Undulating Contact

Burrows and Plant Roots

Plant roots Plant roots

BurrowsBurrows

Burrows

Cross-Bedding

Graded-Bedding

Change in current Velosity Ripple Marks- Depositional

NodulesNodules

Paleosoil leaching

Exposure surface marked by conglomerates

Exfoliation- Weathering

Geodes- diagenetic

Joints Frost Wedging Weathering

Gypsum Cement

Mega FossilsMega Fossils

Coiled Gastropods

Coiled Gastropods

Oysters

Gastropod

Bivalves

Marker BedsMarker BedsMarker Bed (1)

Disconformity

Marker Bed (1)

Marker Bed (2)

Marker Bed (1)

Marker Bed (1)

FossilsBurrowsExfoliationGeodesPebbly SandstoneCross-BeddingCross-Bedded LimestoneFracturesGypsum cement

R1

R2

R3

R4

R5

R6

R8

R9

R10

R7

R11

R12

R13

R14

R15

R16

R18

R19

R17

R20

R21

R22

R23

R24

R25

R26

R27

R28

R29

R30

R31

R32

R33

R34

R35

R36

R39

R40

R38

R37

R65

R66

R67

R68

R69

R54

R53

R55

R56

R58

R59

R64

South West

North East

North West

R57

29.26

29.27

29.28

29.29

29.3

29.31

29.32

29.33

29.34

29.35

29.36

29.37

29.38

29.39

29.4

29.41

29.42

29.43

47.4 47.41 47.42 47.43 47.44 47.45 47.46 47.47 47.48 47.49 47.5 47.51 47.52 47.53 47.54

Southwest

Northeast

Reservation Gate

Northwest

Sabah Al-Ahmad natural reserve northwest of Kuwait bay (330 km2)

PetrographyPetrography

Rock TypesRock Types

Pebbly SandstonesPebbly Sandstones Fine SandstonesFine Sandstones Paleo-soilsPaleo-soils Fossiliferous sandy GrainstonesFossiliferous sandy Grainstones Fossiliferous oolitic-sandy GrainstonesFossiliferous oolitic-sandy Grainstones fossiliferous oolitic-sandy Packstonesfossiliferous oolitic-sandy Packstones Fossiliferous MudstonesFossiliferous Mudstones Peloidal sandy PackstonesPeloidal sandy Packstones

Rock TypesRock Types

Fossiliferous Sandstone 2X Packstone 4X

Packstone 2X Peloidal limestone 2X

Fine Sandstones with PoikilotopicFine Sandstones with Poikilotopic Cement Cement

4X

4X

2X

2X

Rock TypesRock Types

Carbonate Fossiliferous Mudstone 4X Oolitic-peloidal Grainstone 2X

Oolitic Grainstone Sandstone (paleo-soil)

FossilsFossils Mollusks (Bivalves and Gastropods), some Mollusks (Bivalves and Gastropods), some

are oystersare oysters Coral fragmentsCoral fragments Coralline algaeCoralline algae ForaminiferaForaminifera Echinoderm Plates Bone fragments

FossilsFossils

Bivalves 2X Corals 2X

Coralline algae 4XForaminifera 4X

FossilsFossils

Foraminifera 2X

Echinoderm Plate with syntaxial cement 4X

Corals 4X

4X

FossilsFossils

Foraminifera

CementsCementsIsopachous and Spary calcite

4X

Poikilotopic Calcite

CementsCements

2X

PoikilotopicPoikilotopic Gypsum

Spary and microcrystalline calcite

Spary and microcrystalline calcite

MatrixMatrix

Carbonate Matrix

Clay Matrix

Clay Matrix

Matrix

Matrix

GeochemistryGeochemistry

0 10 20 30 40 50 60 70

1

2

3

4

5

6

7

8

9

Mole %

CaC

O3

MgC

O3

Southwestern locationSouthwestern location

123

4

5

6

7

8

9

01000020000300004000050000

12

34

56

78

9Al

FeK

MnNa

P

ppm

05000

1000015000200002500030000

12

34

56

78

910

AlFe

KM

nNa

P

0 5 10

15

20

25

30

35

40

1

2

3

4

5

6

7

8

9

10

Mole %

CaC

O3

MgC

O3

1

2

3

4

5

6

7

8

9

10

First location toward the EastFirst location toward the East

ppm

0 10

20

30

40

50

60

70

80

90

1

2

3

4

5

6

7

8

9

Mole %

CaC

O3

MgC

O3

Second location toward the EastSecond location toward the East

1

2

3

4

5

6

7

8

9

010000200003000040000

12

34

56

78

9Al

FeK

Mn

NaP

ppm

0 10

20

30

40

50

60

70

80

90

1

2

3

4

5

6

7

8

9

10

11

12

Mole %

CaC

O3

MgC

O3

010000200003000040000500006000070000

12

34

56

78

910

1112

AlFe

KMn

NaP

Eastern LocationEastern Location1

2

3

4

5

67891011

12

ppm

Elements Concentration MapsElements Concentration Maps Fossiliferous -sandy limestone-sandy limestone

Al Mn

MgSi Ca

Elements Concentration MapsElements Concentration Mapsfine sandstone with Poikilotopic cementfine sandstone with Poikilotopic cement

Al Mn

Si Mg Ca

Elements Concentration Maps for Elements Concentration Maps for Peloidal-oolitic sandy- grainstonePeloidal-oolitic sandy- grainstone

Al Mn

Si Mg Ca

Elements Concentration Maps-clay MatrixElements Concentration Maps-clay Matrix

Al Mn

Si Mg Ca

CathodoluminesenceCathodoluminesence First diagenetic calcite is with brownish-red First diagenetic calcite is with brownish-red

luminescenceluminescence

Second diagenetic calcite is zoned isopachous and Second diagenetic calcite is zoned isopachous and

spary crystals with yellow, orange, and non -spary crystals with yellow, orange, and non -

luminescent zonesluminescent zones

Third diagenetic calcite is zoned spary crystals with Third diagenetic calcite is zoned spary crystals with

pale blue and non -luminescent zonespale blue and non -luminescent zones

Forth diagenetic calcite show yellow-orange Forth diagenetic calcite show yellow-orange

luminescence luminescence

First and second diagenetic calcite in limestonesFirst and second diagenetic calcite in limestones

4X

10X

Second diagenetic spary calcite crystalsSecond diagenetic spary calcite crystals

10X

In Limestones

In Sandstones

Third diagenetic calcite is zoned spary crystals Third diagenetic calcite is zoned spary crystals with pale blue and non -luminescent zoneswith pale blue and non -luminescent zones

10X

3rd

3rd

3rd

Forth diagenetic calcite (found in Paleo-soils)Forth diagenetic calcite (found in Paleo-soils)

4X

Collecting special parts forCollecting special parts forIsotope AnalysisIsotope Analysis

Oysters

Carbon13 and Oxygen18 Distribution for Kuwait Group

-7.00

-6.00

-5.00

-4.00

-3.00

-2.00

-1.00

0.00

-11.00 -10.00 -9.00 -8.00 -7.00 -6.00 -5.00 -4.00 -3.00 -2.00 -1.00 0.00

18O

13Cwhole limestones shells whole sandstones Spary cements

Normal Marine Isotopic Values ?

High Temperature Fresh water

-11

-10

-9-8-7-6-5-4-3-2-10

R12

R13

R15

R16

R18a

R19

Sam

ple

Num

ber W

ith D

epth

D13C

D18O

Carbon13 and Oxygen18 Distribution for Kuwait

Group With depth

Variation in Carbon13 and Oxygen18 concentrations within Marker Bed 1 (Grainstones and Packstones) from

West to East

Marker Bed 1 (Limestone)

-10.00-9.00-8.00-7.00-6.00-5.00-4.00-3.00-2.00-1.000.00

D13C D18OSouthwest Notheast

Southwest and northwest directions (more depletion)

ConclusionsConclusions

Fieldwork and petrographic data Fieldwork and petrographic data support the idea of several Depositional support the idea of several Depositional environments for the Kuwait Group, environments for the Kuwait Group, which are:which are:

1.1. Mixed clastic-carbonate shelfMixed clastic-carbonate shelf

2.2. High energy beachesHigh energy beaches

3.3. Fluvial-marine , which may be delta Fluvial-marine , which may be delta complexcomplex

4.4. Terrestrial environments- soil horizonsTerrestrial environments- soil horizons

Fieldwork and petrographic data support the Fieldwork and petrographic data support the idea of several unconformity surfaces within idea of several unconformity surfaces within the Miocene-Oligocene Kuwait Group which the Miocene-Oligocene Kuwait Group which were identified by:were identified by:

1.1. Karst surfacesKarst surfaces

2.2. Ripple marksRipple marks

3.3. Nodules baring levelsNodules baring levels

4.4. Paleo-soilsPaleo-soils

5.5. Calcified plants rootsCalcified plants roots

6.6. Reworked (conglomeratic surface)Reworked (conglomeratic surface)

Ghar Fm.

Paleo-soil

Paleo-soil

Paleo-soil Paleo-soil

Roots

Roots

Roots

Dibdibba Fm (Pleistocene)

Lower Fars Fm.

Ghar Fm.

CarboneCarbone1313 and Oxygen and Oxygen1818 isotopes indicate isotopes indicate digenesis under high temperature fresh water digenesis under high temperature fresh water for all the formations which was supported for all the formations which was supported by:by:

1.1. Depleted CarboneDepleted Carbone1313 values (-3.70 to -6.59) values (-3.70 to -6.59)

2.2. Depleted OxygenDepleted Oxygen1818 values (-6.69 to -10.06) values (-6.69 to -10.06)

3.3. Calcified plants roots Calcified plants roots (plant decay (plant decay organic carbon) organic carbon)

4.4. Paleo-soilsPaleo-soils

5.5. Karsts surfacesKarsts surfaces

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Photo by Alham Al-langawi