Upper CampanianeMaastrichtian holostratigraphy of the eastern Danish Basin Finn Surlyk a, * , Susanne Lil Rasmussen a , Myriam Boussaha a , Poul Schiøler b , Niels H. Schovsbo c , Emma Sheldon c , Lars Stemmerik d , Nicolas Thibault a a Department of Geosciences and Natural Resource Management (IGN), University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark b GNS Science, Post Office Box 30368, Lower Hutt, New Zealand c The Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark d Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5e7, DK-1350 Copenhagen K, Denmark article info Article history: Received 8 March 2013 Accepted in revised form 16 August 2013 Available online Keywords: Holostratigraphy Upper CampanianeMaastrichtian Danish Basin Chalk Group abstract One of the most expanded upper CampanianeMaastrichtian successions worldwide has been cored in a series of boreholes in eastern Denmark. A high-resolution holostratigraphic analysis of this part of the Chalk Group has been undertaken on these cores, notably Stevns-1, in order to provide a record of changes in chalk facies, water depths and sea-water temperatures. Combined lithological data, a suite of petrophysical logs including gamma ray (GR) logs, nannofossil and dinoflagellate palaeontology, stable carbon isotopes, seismic reflection and refraction sections form the basis for the definition of two new formations and six members, three of which are new, and for recognition of Boreal nannofossil subzones UC15e BP to UC20d BP . The upper Campanianelowermost Maastrichtian Mandehoved Formation is sub- divided into the Flagbanke and Boesdal Members and the Maastrichtian Møns Klint Formation is sub- divided into the Hvidskud, Rørdal, Sigerslev, Kjølby Gaard Marl and Højerup Members. The Boesdal and Rørdal Members show high GR values and a pronounced chalk-marl cyclicity. The Rørdal and the thin Kjølby Gaard Marl Members have a regional distribution and can be traced over most of the Danish Basin, whereas the Højerup Member is restricted to the easternmost part of Sjælland. The other members consist of rather featureless white chalk. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Long time-series analyses involving stable isotopes, nannofossil palaeontology and cyclostratigraphy of the Boreal Maastrichtian are of major interest in order to better understand the end of the Late Cretaceous greenhouse period. Outcropping sections of the Upper Cretaceous Chalk Group in Denmark all belong to the Maastrichtian Stage and are restricted to eastern Sjælland and northern Jylland (Surlyk, 1984). In order to obtain complete records of the upper Campaniane Maastrichtian chalk two fully cored scientific boreholes Stevns-1 and Stevns-2 were drilled in 2005 on the Stevns peninsula close to the coastal cliff, Stevns Klint in eastern Denmark (Fig. 1; Stemmerik et al., 2006). The 456.1 m deep Stevns-1 borehole penetrated 12.8 m of lower Danian bryozoan limestone and 443.3 m of upper CampanianeMaastrichtian chalk. The core is dated by nannofossil biostratigraphy and spans nannofossil sub- zones UC15e BP to UC20d BP (Sheldon, 2008; Thibault et al., 2012a). The CampanianeMaastrichtian boundary interval is narrowed down to 10 m by combining dinoflagellate data and d 13 C strati- graphic correlation to the GSSP for this boundary at Tercis-les-Bains in southern France and reference sites worldwide (northwest Germany, Gubbio, Italy, DSDP Site 525A, South Atlantic, ODP Site 1210B, western central Pacific, ODP Site 762C, Indian Ocean; Thibault et al. 2012b; Voigt et al. 2012). The cored successions in Stevns-1 and -2 are lithostratigraphically subdivided on the basis of lithological, sedimentological and GR log data. The Stevns-1 core is stratigraphically expanded compared with Stevns-2 and is chosen as the main reference (Fig. 2). A few centimetres of core is missing across the CretaceousePalaeogene boundary but are well exposed at the immediately adjacent coastal cliff of Stevns Klint. Seismic refraction data based on a line connecting the Stevns-1 and -2 boreholes situated 8 km apart show several marked stepwise downhole increases in velocity, coinciding with some of the lith- ostratigraphic boundaries recognised here (Nielsen et al., 2011). The Stevns-1 core is an excellent standard reference for the * Corresponding author. E-mail address: [email protected] (F. Surlyk). Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes 0195-6671/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.cretres.2013.08.006 Cretaceous Research 46 (2013) 232e256
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
lable at ScienceDirect
Cretaceous Research 46 (2013) 232e256
Contents lists avai
Cretaceous Research
journal homepage: www.elsevier .com/locate/CretRes
Upper CampanianeMaastrichtian holostratigraphy of the easternDanish Basin
Finn Surlyk a, *, Susanne Lil Rasmussen a, Myriam Boussaha a, Poul Schiøler b,Niels H. Schovsbo c, Emma Sheldon c, Lars Stemmerik d, Nicolas Thibault a
a Department of Geosciences and Natural Resource Management (IGN), University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmarkb GNS Science, Post Office Box 30368, Lower Hutt, New Zealandc The Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmarkd Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5e7, DK-1350 Copenhagen K, Denmark
a r t i c l e i n f o
Article history:Received 8 March 2013Accepted in revised form 16 August 2013Available online
Keywords:HolostratigraphyUpper CampanianeMaastrichtianDanish BasinChalk Group
* Corresponding author.E-mail address: [email protected] (F. Surlyk).
0195-6671/$ e see front matter � 2013 Elsevier Ltd.http://dx.doi.org/10.1016/j.cretres.2013.08.006
a b s t r a c t
One of the most expanded upper CampanianeMaastrichtian successions worldwide has been cored in aseries of boreholes in eastern Denmark. A high-resolution holostratigraphic analysis of this part of theChalk Group has been undertaken on these cores, notably Stevns-1, in order to provide a record ofchanges in chalk facies, water depths and sea-water temperatures. Combined lithological data, a suite ofpetrophysical logs including gamma ray (GR) logs, nannofossil and dinoflagellate palaeontology, stablecarbon isotopes, seismic reflection and refraction sections form the basis for the definition of two newformations and six members, three of which are new, and for recognition of Boreal nannofossil subzonesUC15eBP to UC20dBP. The upper Campanianelowermost Maastrichtian Mandehoved Formation is sub-divided into the Flagbanke and Boesdal Members and the Maastrichtian Møns Klint Formation is sub-divided into the Hvidskud, Rørdal, Sigerslev, Kjølby Gaard Marl and Højerup Members. The Boesdal andRørdal Members show high GR values and a pronounced chalk-marl cyclicity. The Rørdal and the thinKjølby Gaard Marl Members have a regional distribution and can be traced over most of the Danish Basin,whereas the Højerup Member is restricted to the easternmost part of Sjælland. The other membersconsist of rather featureless white chalk.
� 2013 Elsevier Ltd. All rights reserved.
1. Introduction
Long time-series analyses involving stable isotopes, nannofossilpalaeontology and cyclostratigraphy of the Boreal Maastrichtianare of major interest in order to better understand the end of theLate Cretaceous greenhouse period. Outcropping sections of theUpper Cretaceous Chalk Group in Denmark all belong to theMaastrichtian Stage and are restricted to eastern Sjælland andnorthern Jylland (Surlyk, 1984).
In order to obtain complete records of the upper CampanianeMaastrichtian chalk two fully cored scientific boreholes Stevns-1and Stevns-2 were drilled in 2005 on the Stevns peninsula closeto the coastal cliff, Stevns Klint in eastern Denmark (Fig. 1;Stemmerik et al., 2006). The 456.1 m deep Stevns-1 boreholepenetrated 12.8 m of lower Danian bryozoan limestone and443.3 m of upper CampanianeMaastrichtian chalk. The core is
All rights reserved.
dated by nannofossil biostratigraphy and spans nannofossil sub-zones UC15eBP to UC20dBP (Sheldon, 2008; Thibault et al., 2012a).The CampanianeMaastrichtian boundary interval is narroweddown to 10 m by combining dinoflagellate data and d13C strati-graphic correlation to the GSSP for this boundary at Tercis-les-Bainsin southern France and reference sites worldwide (northwestGermany, Gubbio, Italy, DSDP Site 525A, South Atlantic, ODP Site1210B, western central Pacific, ODP Site 762C, Indian Ocean;Thibault et al. 2012b; Voigt et al. 2012). The cored successions inStevns-1 and -2 are lithostratigraphically subdivided on the basis oflithological, sedimentological and GR log data. The Stevns-1 core isstratigraphically expanded compared with Stevns-2 and is chosenas the main reference (Fig. 2). A few centimetres of core is missingacross the CretaceousePalaeogene boundary but are well exposedat the immediately adjacent coastal cliff of Stevns Klint. Seismicrefraction data based on a line connecting the Stevns-1 and -2boreholes situated 8 km apart show several marked stepwisedownhole increases in velocity, coinciding with some of the lith-ostratigraphic boundaries recognised here (Nielsen et al., 2011).The Stevns-1 core is an excellent standard reference for the
A B
Fig. 1. (A). Map showing the main structural elements and the thickness of the Chalk Group in the study region and localities mentioned in the text. The red outline indicates thedetailed locality map (B) which shows the position of the Stevns-1 and Stevns-2 cored boreholes and the linking seismic line. (For interpretation of the references to colour in thisfigure legend, the reader is referred to the web version of this article.)
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 233
Maastrichtian Stage in the Boreal Realm and provides an eminentexpanded stratigraphical and climatic record of the end of theCretaceous Period.
The chalk forms the most important reservoir rock for hydro-carbons in the Danish North Sea Sector, and Maastrichtian chalkand Danian bryozoan limestone are important groundwater res-ervoirs in northern Jylland and eastern Sjælland (Fig. 1). The eco-nomic importance of the Chalk Group is illustrated by numeroussedimentological, stratigraphical, palaeontological and reservoirstudies based on seismic and well data in the North Sea and onseismic data and outcrops in eastern Denmark (e.g. Surlyk et al.,2003, and references therein; Lykke-Andersen and Surlyk, 2004;Ineson et al., 2006; Sheldon, 2006, 2008; Surlyk and Lykke-Andersen, 2007; Esmerode et al., 2007; Anderskouv et al., 2007;Madsen and Stemmerik, 2009, 2010; Sheldon et al., 2010, 2012, andGEUS, unpublished data; Surlyk et al., 2010a,b; Nielsen et al., 2011;Thibault, 2010a,b, Thibault et al., 2012a; Anderskouv and Surlyk,2011, 2012).
The Upper CretaceouseDanian Chalk Group of the Danish Basinhas not been fully lithostratigraphically subdivided and only a fewmembers have been recognised in the upper Maastrichtian atKjølby Gaard, northern Jylland (Kjølby GaardMarl Member), Rørdalquarry, northern Jylland (Rørdal Member) and Stevns Klint, easternSjælland (Sigerslev and Højerup Members) and several of thesemembers have also been identified in various boreholes (Troelsen,1955; Larsen, 1998; Surlyk et al., 2006, 2010a; Nielsen andJørgensen, 2008). This limited stratigraphic subdivision is un-doubtedly due to the rather monotonous appearance of the whitechalk and the wide scatter of outcrops restricted to eastern Sjæl-land, Møn and northern Jylland (Fig. 1). Biostratigraphic zonationshave, however, been made on the basis of belemnites, brachiopods,
foraminifers, dinoflagellates and coccoliths (Birkelund, 1957;Stenestad, 1971, 2005; Surlyk, 1970, 1984; Hansen, 1977; Perch-Nielsen, 1979a,b, 1985; Schiøler, 1993; Schiøler and Wilson, 1993;Sheldon, 2006, 2008; Thibault et al., 2012a). A high-resolutioncarbon-isotope stratigraphy has been recently established andtied to the German chalk (Thibault et al., 2012a, Voigt et al., 2012)and to ODP Site 762C, Indian Ocean (Thibault et al., 2012b). Thelatter was chosen because it shows a good cyclostratigraphic signalthat allowed a tie to the astronomical solutionwhich has been laterconfirmed by the study of Maastrichtian sections in Spain (Thibaultet al., 2012b; Batenburg et al., 2012).
During the last 10 years it has become increasingly clear thatchalk deposition in eastern Denmark was highly dynamic withpersistent bottom currents sculpting the sea floor into a system ofridges and valleys with amplitudes up to 150 m superimposed bysmaller topographic features (Lykke-Andersen and Surlyk, 2004;Surlyk and Lykke-Andersen, 2007; Esmerode et al., 2007; Surlyket al., 2010b). The Stevns-1 and -2 boreholes were drilled imme-diately adjacent to the coastal cliff of Stevns Klint in order toinvestigate the lithological composition and stratigraphic devel-opment of the upper part of the Chalk Group (Stemmerik et al.,2006; Schovsbo et al., 2008; Rasmussen and Surlyk, 2012).Stevns-1 (DGU 218.1938) was drilled at Flagbanke, 2 km east of thevillage Sigerslev near the culmination of the undulating Creta-ceousePalaeogene (K/Pg) boundary surface and penetrated a ridgesuccession. Stevns-2 (DGU 218.1945) was drilled in the Boesdalquarry approximately 8 km further south along the cliff andpenetrated a valley-fill succession. The two boreholes, 456.1 m and350.6 m deep, respectively, are fully cored with 100% recovery, anda suite of petrophysical logs were obtained from the open holes(Figs. 2 and 3; Stemmerik et al., 2006; Bonnesen et al., 2009). Both
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256234
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 235
boreholes reached down into the Campanian and the cores thusprovide the first detailed lithological information about the upperCampanianeMaastrichtian chalk in eastern Denmark, includingthe outcropping upper Maastrichtian Sigerslev and HøjerupMembers.
The present paper presents a lithostratigraphic subdivision ofthe upper part of the Chalk Group in eastern Denmark based ondata from the Stevns-1 and -2, Karlslunde-1, Solrød-2, Tune-1 andTuba-13 boreholes, and outcrops at Stevns Klint and in the coastalcliff of Møns Klint about 30 km to the south (Fig. 1). More detailedsedimentological, stratigraphical, ichnological and diageneticstudies of the cores are in progress or have been presented else-where (Madsen and Stemmerik 2009, 2010; Rasmussen andSurlyk, 2012; Thibault et al., 2011, 2012a). Tentative correlationsto lithostratigraphic schemes in northern Germany and theDanish, Norwegian, UK and Dutch North Sea sectors are alsopresented.
The aim of this study is to present a holostratigraphic scheme forthe cored upper CampanianeMaastrichtian succession in easternDenmark, including a new lithostratigraphy, nannofossil anddinoflagellate biostratigraphy, petrophysical logs, and stableisotope curves. This is based on the Stevns-1 core, which serves as astandard for the Boreal upper CampanianeMaastrichtian and is oneof the most expandedMaastrichtian successions knownworldwide(Thibault, 2010b).
2. Geological setting
The Danish Basin is bordered to the north by the faulted andinverted Sorgenfrei-Tornquist Zone and to the south by the Ring-købing-Fyn High, a prominent basement feature. Stevns-1 and -2are situated at the transition from the eastern end of the high to thesouth-eastern margin of the Danish Basin, and the Karlslunde-1,Solrød-2, Tune-1 and Tuba-13 boreholes are located in theeastern end of the basin (Fig. 1). Several important NNW�SSE, N�Sand NNE�SSW orientated faults occur in the Øresund strait be-tween Denmark and Sweden. The Upper CretaceouseDanian ChalkGroup is widely distributed in the Danish Basin, attaining thick-nesses of more than 2000 m in the eastern part of the basin adja-cent to the Sorgenfrei-Tornquist Zone (Liboriussen et al., 1987). Thegroup decreases in thickness towards the south and is about1000 m thick in the study area and around 500 m thick on the is-land of Møn to the south over the eastern central part of theRingkøbing-Fyn High.
3. Methods
The Stevns-1 core has been logged in detail for lithology, chalk-marl cyclicity, primary and secondary sedimentary structures,body fossils, trace fossils, degree of bioturbation, diagenetic fea-tures, and a set of standard petrophysical logs has been obtained.Samples were collected for measurements of stable isotopes (every0.25 m) and for nannofossil analysis (every 5 m or closer at certainlevels) (Thibault et al., 2012a). The core was also sampled, thoughless systematically for XRD analysis of the insoluble residue, aspresented by Madsen (2009). The core is correlated with highresolution reflection seismic profiles recorded close to the coast-line of Stevns Klint (Lykke-Andersen and Surlyk, 2004), and a
Fig. 2. Schematic overview log of the Stevns-1 core. A detailed log with all available informdinoflagellate zones shown in the figure is based on identification of biozones at sample depoverlying biozone in the figure. Correlation of the brachiopod zones (Surlyk, 1984) with theisotope correlations between Kronsmoor, Hemmoor and Stevns-1 (Thibault et al., 2012Hvidskud, Rügen and Hemmoor (Surlyk, 1970) and the zonation of Kronsmoor (Surlyk, 1982)jasmundi, jea ¼ jasmundieacutirostris, aes ¼ acutirostrisespinosa, ses ¼ spinosaesubtilis, ses ¼ tenuicostataesemiglobularis, seh ¼ semiglobularisehumboldtii, hes ¼ humboldtiiesteven
comparison is made with a velocity model based on a refractionseismic line between the Stevns-1 and -2 boreholes (Nielsen et al.,2011).
New results on dinoflagellate biostratigraphy are presentedhere. A total of 37 samples were collected from Stevns-1 in theinterval 455.90e3.10 m with an average sample spacing ofapproximately 12 m (Appendix 1). The samples were processedfollowing standard palynological processing techniques for pre-Quaternary samples (cf. Batten, 1999), including treatment with5N hydrochloric acid, 40% hydrofluoric acid and two minutesoxidation in 36% nitric acid followed by heavy liquid separation.The sample residue was filtered on 11 mm filter cloth and mountedin glycerine jelly. The samples were studied qualitatively for di-noflagellates, acritarchs and chlorophytes. Biostratigraphic resultsin the interval from c. 353 me250 m, bracketing the CampanianeMaastrichtian boundary, were presented by Thibault et al. (2012a).Dinoflagellate taxa mentioned in the text are fully referenced in theLentin and Williams index (Fensome and Williams, 2004). Thebiostratigraphic breakdown into nannofossil and dinoflagellatezones shown in Fig. 2 and Appendix 2 is based on identification ofbiozones at sample depths. However, as a convention followed inthe two figures biozones have been extended upwards to the baseof the overlying biozone. A correlation between the brachiopodbiozones of Surlyk (1970, 1982, 1984) and the nannofossil anddinoflagellate zones, is proposed (Fig. 2; Appendix 2). It is tentative,however, because the Stevns-1 core was too lithified to allowwashing for the micromorphic brachiopods which form the basisfor the brachiopod zonation.
4. Stratigraphy
4.1. Facies and ichnofauna
The Stevns-1 core comprises pure, completely bioturbatedchalk, marly chalk, faintly laminated chalk, thin marl beds andintraclast conglomerates (Figs. 2, 4e6) (Rasmussen and Surlyk,2012).
Pure chalk: this lithology occurs both as units up to 20 m thickand as decimetre to metre-thick beds, alternating with marlychalk beds. The chalk is mainly completely burrow mottled andthe trace fossils include Thalassinoides, Planolites, Zoophycos,Chondrites, and rare Taenidium and Phycosiphon (Fig. 2, 4A). A faintprimary lamination occurs in places. Inoceramid bivalve frag-ments are common at certain levels, fragments of echinoids, as-teroids, other bivalves and sponges occur in places, and bryozoansare particularly common in the lower Sigerslev and HøjerupMembers.
Marly chalk: marly chalk occurs as decimetre to metre-thickbeds, and is most prominent in the Flagbanke, Boesdal andRørdal Members, whereas it is rare in the Sigerslev and HøjerupMembers (Figs. 2, 4, 5A). Themarly chalk is only slightly greyer thanthe pure chalk and is difficult to recognise in a dry core. It containsthe same body and trace fossils as the pure chalk. Flaser structuresformed by burial dissolution are common in the marly chalk inStevns-1 (Fig. 4C).
Marl: this facies comprises distinct and mainly well-defineddark grey millimetre to centimetre-thick laminae and layersoccurring preferentially in the middle part of the marly chalk beds
ation is shown in Appendix 2. The biostratigraphic breakdown into nannofossil andths. However, as a convention, biozones have been extended upwards to the base of theother zonations is tentative and is based on the combined evidence from the carbona) and the brachiopod zonation and correlations between the Rørdal-1 borehole,. The brachiopod zones are from below: tel ¼ tenuicostataelongicollis, lej ¼ longicollisep ¼ subtilisepulchellus, pep ¼ pulchellusepulchellus, pet ¼ pulchellusetenuicostata, tesis, sec ¼ stevensisechitoniformis.
0
50
150
100
200
250
300
350
400
450
2.52.01.51.0 0.35.0
M5+
M4+
Dep
th(m
)
δ13C(‰ V-PDB)
c
M1+
M1-
M2+
M2-
M3-(a)
M4-(a)
M4-(b)
M3+
CMB a
CMB c
UC15U
C16
a-bBP
cBP
dBP
UC18
b-cBP
aBP
dBP
UC19
UC
20
Borealnannofossil
zonation(BP)
C. daniae
T. orionatus
R. levis
B. parca constricta
N. frequens
L. quadratus
E. eximius
KPg
δ13C(‰ V-PDB)
a
CMB b
M3-(b)
T. stemmerikii
UC17
P. mgayae
Exmouth Plateau event
M4-(a)
M4-(b)
M4+
2.25 2.5 2.75 3 3.25
M3-(b)
M3+
M2+
M1+
CMBb
CMBa
C1-
AcmeM. murus
M. prinsii
M. murus
R. fructicosa
+ C. contusa
L. quadratus
B. parca constricta
T. orionatus
A. mayaroensisR. levis
U. trifidus
T. stemmerikii
+ U. gothicus
N. frequens
CMBc
M5+
P. mgayae
29r
30n
30r
31n
31r
32n
32r
33n
d
b
a
UC
20U
C19
UC
18U
C16
-17
UC
15e
Maa
stric
htia
nC
ampa
nian
Stag
eM
agne
to-
-stra
tigra
phy
Ma
(K-P
gat
66)
66.0
67.0
68.0
69.0
70.0
71.0
72.0
73.0
73.5
72.5
71.5
70.5
69.5
67.5
66.5
74.0
74.5
75.0
75.5
76.0
76.5
405
kyr
cycl
es
Ma1Ma2Ma3Ma4Ma5Ma6Ma7Ma8Ma9Ma10
Ma12Ma11
Ma13Ma14Ma15Ca1Ca2Ca3Ca4Ca5
Not
stud
ied
for
cycl
ostra
tigra
phy
Ca6
c
PFzo
nes
A.mayaroensis
C.contusa
H.rajagopalani
G.arca
0 2040-20
Grey level405 kyr filter
b
lateCampanianevent ?
M. prinsii
M. murus
L. quadratus
A. mayaroensis
R. fructicosa
R. levisC. contusa
T. orionatus
B. parca
constricta
U. trifidus
+U. gothicus
G. gansseri
G. aegyptiaca
R. calcarata
lateCampanian
event
Acm
eM.murus
Gubbio composite curveItaly d
BottaccioneContessa
2.0 2.2 2.4 2.6 2.8
MME
290
300
310
320
330
340
350
360
370
380
m
UC
20d
UC
19U
C16
UC18UC17
A.mayaroensis
R.fructicosa
G.gansseri
G.aegyptiaca
G.havanensis
R.calcarata
PFzo
nes
Teth
yan
nann
o.zo
nes
(TP)
Base C32n2n
Base C31r
Mag
neto
--s
tratig
raph
yM
aast
richt
ian
Cam
pani
anSt
age
31n
30n
29r
31r
32n
32r
33n
M3-(a)
M5+
M4-(a)
M3+
M2+
M1+
Base C32n2n
Base C31r
C1-
CMB c
C1-
b-c
a
Stevns-1Denmark
δ13C(‰ V-PDB)
ODP 762CIndian Ocean
TPTP
TP
?
E. eximius
68.5
Teth
yan
nann
o.zo
nes
(TP)
F.Surlyket
al./Cretaceous
Research46
(2013)232
e256
236
A C
B
Fig. 4. A. Thalassinoides, Zoophycos and Chondrites burrows on a background of totally bioturbated chalk. Stevns-1, upper Maastrichtian, Hvidskud Member, 152.6 m. B. Pure, totallybioturbated chalk characteristic of many levels of Stevns-1. Stevns-1, upper Maastrichtian, Hvidskud Member, 147.2 m. C. Marly flaser chalk formed by burial dissolution of marlychalk. Stevns-1, upper Maastrichtian, Rørdal Member, 98.3 m.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 237
in an apparently cyclic manner, especially in the Flagbanke, Boesdaland Rørdal Members, whereas they are rare in the other members(Figs. 2, 5B).
Conglomerate: beds of chalk intraclast conglomerates up to onemetre thick occur at many levels but are particularly common inthe Boesdal Member which is characterised by this facies (Figs. 2,6A). The clasts are millimetres to a few centimetres in diameter
Fig. 3. Correlation of the d13C curve of Stevns-1 with the astronomically calibrated Hole 762Cpoints. (a) d13C curve compiled after Thibault et al. (2012b) and Stoll and Schrag (2001). (b) 40carbon-isotope stratigraphy after Thibault et al. (2012a). (d) Gubbio carbon-isotope stratigrapet al. (2012).
and are subrounded to angular. Upwards transitions from frac-tured chalk to brecciated chalk, to matrix-supported conglomerateand back again to brecciated and then fractured chalk at the upperboundary are common. This type of conglomerate is not inter-preted to be of primary depositional nature but may reflecthydrofracturing brecciation and matrix fluidisation followingburial.
(Thibault et al. 2012b), and the Gubbio section with magnetostratigraphy and d13C tie-5 kyr eccentricity filter after Husson et al. (2011). (c) Stevns-1 nannofossil zonation andhy after Voigt et al. (2012) and nannofossil and foraminifer biostratigraphy after Gardin
A B
Fig. 5. A. Marly chalk typically occurring alternating with beds of pure chalk. Stevns-1, uppermost Campanian, Boesdal Member, 325.7 m. B. Well-defined marl layer with fragmentof inoceramid bivalve. Stevns-1, Flagbanke Member, 421.25 m.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256238
Skeletal laminae: millimetre-thick laminae of fragmentedbryozoans, bivalves and relatively large benthic foraminifers, arecommon throughout, in particular associated with the uppermostconglomerates of the Boesdal Member and in the HvidskudMember (Figs. 2, 6B). The laminae are interpreted as representingconcentrations in small burrow fills (cf. Kennedy, 1967, 1970;Ekdale and Bromley, 1983; Lauridsen et al., 2011).
4.2. Biostratigraphy
4.2.1. Calcareous nannofossil biozonationThe Boreal nannofossil (UCBP) zonation of Burnett (1998) is
applied for the upper Campanian�Maastrichtian part of the Stevns-1 core (Fig. 2) (Sheldon, 2008; Thibault et al., 2012a). The studied
interval spans nannofossil subzones UC15eBP to UC20dBP, and theCampanianeMaastrichtian boundary is identified within UC16dBP.
Zone UC16BP is subdivided from the base into subzones aebBP,cBP, and dBP, and zone UC20BP is similarly subdivided into subzonesaBP, becBP and dBP. Subzone UC16dBP spans the CampanianeMaastrichtian boundary and includes the boundary interval in themiddle part, which has been narrowed down to 10 m between 330and 320 m by means of dinoflagellates and carbon isotope stra-tigraphy (Thibault et al., 2012a,b). The middle lower Maastrichtianzones UC17BPe18BP are very thin.
There is no international agreement on the position of thelowereupper Maastrichtian boundary and how it should bedefined. However, Gardin et al. (2001) suggested the use of theconcomitant first occurrences (FO) of nannofossil Lithraphidites
A C
B
Fig. 6. A. Intraformational conglomerate characteristic of the upper Campanianelowermost Maastrichtian Hvidskud Member. Both the lower and upper boundaries are gradational.Stevns-1, lowermost Maastrichtian, Boesdal Member, 318.6 m. B. Skeletal laminae composed of foraminifers, fragmented bryozoans and other small fossils, and interpreted asskeletal concentrations in burrow fills. Stevns-1, upper Maastrichtian, Sigerslev Member, 63.7 m. C. Chalk showing faint primary lamination and scattered stylolite seams. Stevns-1,lower Maastrichtian, Hvidskud Member, 176.4 m.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 239
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256240
quadratus and planktonic foraminifer Abathomphalus mayaroensisto define this boundary in the Gubbio section in Italy. This approachis followed here and in Stevns-1, and the boundary is accordinglydefined at the base of UC20BP, at the FO of L. quadratus (Fig. 7;Thibault et al., 2012a,b). The classical belemnite-based definition ofthe lowereupper Maastrichtian boundary (Schmid et al., 2004) isanother possibility, but this can only be used in the Boreal Realm.The base of the carbon-isotope event M3-(a) (MME of Voigt et al.,2012) coincides with the base of UC20 BP in Stevns-1 (Fig. 3). Thisevent has been identified in the Rørdal-1 borehole (Denmark),Hemmoor (North Germany) and Gubbio (Italy) and is thus usefulfor long-distance correlations. The base of this event may serve asan alternative marker for the lowereupper Maastrichtianboundary.
Fig. 7. Correlation of GR logs between Stevns-1, Stevns-2, Rørdal-1, R
4.2.2. Dinoflagellate cysts, acritarchs and chlorophytesThe dinoflagellate stratigraphy of Stevns-1 is new and is there-
fore presented in some detail in this chapter. Reworking ofsediment and its associated marine palynomorphs, mostly di-noflagellates, occurred episodically in the succession penetrated bythe Stevns-1 well and shows up as reappearance of taxa well abovetheir true stratigraphic top. These reappearances of older dinofla-gellate taxa occur in pulses affecting one or more samples in suc-cession and are separated by sample intervals in which the taxa areabsent. For this reason the last occurrence (LO) of some taxa,including a few key markers may be subject to interpretation. Inmost cases, the LO of a taxon is taken at its last consistent occur-rence. The episodic pattern of reworked taxa may reflect that thesediment was reworked in pulses, separated by periods of
ørdal quarry and Karlslunde-1. Nannofossil zonation indicated.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 241
uninterrupted sedimentation. These pulses were probably causedby episodes of inversion tectonics along the Ringkøbing-Fyn High.
Based on the occurrence pattern of a number of key di-noflagellates, the upper c. 250 m of the Stevns-1 succession, rep-resenting the upper Maastrichtian to lowermost Danian intervalcan readily be correlated with the zonations for the onshore DanishBasin (Hansen, 1977) and the Central North Sea (Schiøler andWilson, 1993) as well as northern Germany (Marheinecke, 1992).North European zonation schemes covering the entire successioncored in Stevns-1 include those proposed by Wilson (1974),Schumacker-Lambry (1977) and Slimani (1995, 2001, 2011).Although thementioned zonation schemes inmany cases are basedon different index taxa, there is a high degree of similarity betweenthem, and the lower Stevns-1 succession can relatively easily becorrelated with any of these zonation schemes (see e.g. text-fig. 11in Slimani, 2001 for a comparison between North European dino-flagellate zones). For reasons of simplicity and to avoid zonalduplication, the Stevns-1 dinoflagellate succession is herein onlycorrelated with the zonations of Hansen (1977), Schiøler andWilson (1993) and Slimani (2001, 2011, Appendix 1, Fig. 4). Keydinoflagellates are highlighted in the distribution chart (Appendix1) and important stratigraphic markers are illustrated in Figs. 8and 9 Schiøler and Wilson (1993) and Slimani (2001, 2011) corre-lated their dinoflagellate zones with macrofossil zones and thiscorrelation is adapted herein (Appendix 1).
The occurrence in Stevns-1 of a number of secondary dinofla-gellate and acritarch taxa, previously observed in the CampanianeDanian succession in northern Europe (e.g. Wilson, 1974; Schiøler,1993, Schiøler and Wilson, 1993, 1994; Slimani, 1995; 2001;Marheinecke, 1992; Brinkhuis and Schiøler, 1996) can be used tofurther underpin their occurrence pattern in the North Europeanzonation schemes. These taxa are dealt with below under the in-dividual zones and are also highlighted in the distribution chart(Appendix 1). The lowermost part of Stevns-1, from 455.90 m to434.87 m is correlated with the Hystrichokolpoma gamospina zoneof Slimani (2001), based on the first occurrence (FO) of Areoligeracoronata in the sample directly above this interval, at 419.90 m.Areoligera senonensis, a taxon very similar to A. coronata has FO inthe highest sample in this zone, at 434.87 m. The base of theH. gamospina zone is probably not reached in Stevns-1 based on theabsence of key markers for the underlying E.? masureae zone, suchas Sepispinula ambigua and Thalassiophora? spinosa (Slimani, 2011).This interval correlates with the upper part of the upper CampanianB. mucronata belemnite zone.
The interval from 419.90e394.93 m belongs to the A. coronatazone of Slimani (2011), based on the FO of the nominate species at419.90 m and the absence of Samlandia mayii, the marker for thenext higher zone. This interval has the FO of Neoeurysphaeridiumglabrum and Prolixosphaeridium nanum, (394.93 m) and the FO ofCannosphaeropsis utinensis (407.90 m). The LO of Palynodiniumhelveticum and Palaeohystrichophora infusorioides is at the base ofthe interval, at 419.90 m. This interval correlates with the upperpart of the upper Campanian B. mucronata belemnite zone.
The FO of Samlandia mayii at 381.71 m marks the base of theS. mayii zone of Slimani (2011). The top of this zone is interpreted atthe LO of representatives of the genus Odontochitina (asO. operculata) at 325.22 m. The LO of this genus as well as the LO ofCorradinisphaeridium horridum and Raetiaedinium evittigratia are allclosely below the CampanianeMaastrichtian boundary in its typesection whereas the LO of S. mayii is above the boundary(Antonescu et al., 2001; Schiøler and Wilson, 2001). Since all fourtaxa have a similar occurrence pattern in the Stevns-1 well, theboundary was placed between the samples at 339.88 and 310.20 m,based on dinoflagellate biostratigraphy (Thibault et al., 2012a).Based on this and with support from correlation of d13C and
nannofossil events Thibault et al. (2012a) further narrowed in theCampanianeMaastrichtian boundary interval to c. 330e320 m inStevns-1. A number of taxa have FO in the S. mayii zone: Cerodiniumdiebelii (381.71 m), Corradinisphaeridium horridum (364.72 m),Fibrocysta ovalis (381.71 m), Impagidinium rigidaseptatum(339.88 m), Microdinium carpentierae (364.72 m), Montanarocystaeamiliana (352.28 m), Palaeocystodinium golzowense (325.22 m),Rottnestia wetzelli brevispinosa (364.72 m), Trithyrodinium evittii(381.71 m) and Xenikoon sp. A of Foucher and Robaszynski (1977)(381.71 m). Taxa with LO in this zone are: C. horridum (339.88 m),M. aemiliana (339.88 m), R. evittigratia (339.88 m), Samlandia car-narvonensis (352.28 m), S. mayii (364.72 m) and Trichodinium cas-tanea (352.28 m). The S. mayii zone correlates with the uppermostCampanian Belemnitella langei belemnite zone.
The interval from 310.20 m to 205.18 m is correlated with theMembranilarnacia liradiscoides zone of Slimani (2001), based on theabsence of Odontochitina spp. from the base of the interval and theLO of Eatonicysta hapala in the sample at 205.18 m. The upper partof the interval, from the FO of Triblastula utinensis at 250.08 m tothe LO of E. hapala falls within the Eatonicysta hapala subzone of theTriblastula utinensis zone of Schiøler and Wilson (1993) in theirCentral North Sea zonation scheme. Thus, the M. liradiscoides zoneof Slimani (2001) may conveniently be divided into an upper partidentical to the E. hapala subzone of Schiøler andWilson (1993) anda lower, currently unnamed interval characterised by the jointabsence of Odontochitina spp. and T. utinensis. The lower part of thisinterval (310.20e264.98m) below the E. hapala subzone, has the FOof Neonorthidium perforatum (264.98 m) and the LO of Spongodi-nium delitiense (264.98 m). The M. liradiscoides zone, including theE. hapala subzone, correlates with the lowermost MaastrichtianBelemnella lanceolata belemnite Zone. The Maastrichtian belemnitezones are those of Jeletzky (1951) and Birkelund (1957) and theavailable data do not allow correlation with later, more refinedbelemnite zonations.
The sample at 190.55 m can be assigned to the Alterbidiniumacutulum subzone of the T. utinensis zone in the zonation scheme ofSchiøler and Wilson (1993), based on the LO of A. acutulum in thesample. Subtilisphaera sp. 2 of Marheinecke has FO in the sample.This subzone largely correlates with the lower MaastrichtianBelemnella occidentalis belemnite zone, but does not cover theuppermost part of that zone.
The interval from 175.16e115.26 m is correlated with the Can-nosphaeropsis utinensis subzone of the T. utinensis zone of Schiølerand Wilson (1993), based on the LO of T. utinensis at 115.26 m.The base of this interval is close to the upperelower Maastrichtianboundary in Stevns-1 as determined by nannofossil evidence, at theFO of Lithraphidites quadratus, located in the interval 175.22e170.50 m (Thibault et al., 2012a). Deflandrea galeata (144.65 m),Glaphyrocysta perforata (115.26 m), Hystrichosphaeropsis ovum(175.16m) andHystrichosphaeropsis perforata (144.65m) have FO inthe zone, Subtilisphaera sp. 2 of Marheinecke (1992, 160.13 m),C. utinensis (160.13 m) and H. perforata (144.65 m) have LO in thezone. The zone correlates with the uppermost part of the Belem-nella occidentalis zone and the lower part of the Belemnitella juniorbelemnite zone.
The interval from 100.90 m to 75.04 m is correlated with theIsabelidinium cooksoniae zone of Schiøler and Wilson (1993), basedon the LO of the nominate species at 75.04 m. Cassiculosphaeri-dium? tocheri has FO in the zone, at 100.90 m. Raphidodiniumfucatum and the acritarch Palaeostomocystis reticulata have LO at100.90 m. The I. cooksoniae zone correlates with the upper part ofthe Belemnitella junior belemnite zone.
The sample at 60.16 m is assigned to the Palaeocystodiniumdenticulatum zone of Schiøler and Wilson (1993) based on the jointabsence of I. cooksoniae and Hystrichostrogylon borisii and its
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256242
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 243
stratigraphic position above the I. cooksoniae zone. Palae-ocystodinium denticulatum is restricted to this zone. This zonecorrelates with the lowermost part of the Belemnella kazimir-oviensis belemnite zone.
The sample at 44.90 m is correlated with the Hystrichostrogylonborisii zone of Schiøler and Wilson (1993), based on the FO of thenominate species in the sample. Prolixosphaeridium nanum andMicrodinium sonciniae have LO in the zone. This zone correlateswith the lower part of the Belemnella kazimiroviensis belemnitezone above the P. denticulatum zone.
The interval from 30.12 m to 18.11 m can be assigned to thePalynodinium grallator zone of Hansen (1977), based on the FO ofthe nominate species at 30.12 m and the LO of the same species at18.11 m. The interval can be further subdivided into the lowerTanyosphaeridium magdalium subzone and the upper Thalassiphorapelagica subzone (23.17e18.11 m) of Hansen (1977), based on theFO of T. pelagica at 23.17 m. Hystrichokolpoma bulbosa (30.12 m) andMuratodinium fimbriatum (18.11 m) have FO in the P. grallator zoneand C.? tocheri, N. perforatum and Pterodinium cretaceum all have LOin the zone, at 23.17 m. Disphaerogena carposphaeropsis is restrictedto the interval 30.12e23.17 m. The P. grallator zone correlates withthe upper part of the Belemnella kazimiroviensis zone.
A barren interval represented by the samples at 14.07 and12.25 m underlies two samples at 7.04 and 3.1 mwith a very sparsedinoflagellate assemblage. The barren samples cannot be assignedto any dinoflagellate zones, but based on nannofossil evidence,which places the MaastrichtianeDanian boundary in the interval12.47e14.29 m (Sheldon, 2008) the barren samples are closelyassociated with that boundary. The presence of Senoniasphaerainornata in the two samples at 7.04 and 3.10 m, together with theabsence of P. grallator is used to correlate the interval with theS. inornata subzone of the Danian Damassadinium californicum zoneof Hansen (1977). Furthermore, the FO of Xenicodinium lubricum inthe sample at 3.10 m can be used to assign that sample to theX. lubricum zonule of Hansen (1977), the highest of the three zon-ules in the S. inornata subzone. The lower two zonules, the Carpa-tella cornuta zonule and the Tectatodinium rugulatum zonule, arenot accounted for, but may be represented by some or the entireunderlying barren interval.
4.3. Bulk carbonate carbon isotopes
A high-resolution d13C stratigraphy allows recognition of 15isotopic events and has been correlated with successions innorthwest Germany, the Indian Ocean, the South Atlantic, and thecentral Pacific (Thibault et al., 2012a,b; Voigt et al., 2012). Correla-tion of this curve with that of the CampanianeMaastrichtian GSSPat Tercis les Bains and with Hole 762C, Indian Ocean, for which anastronomical calibration has been performed (Thibault et al.,2012a,b), made it possible to identify the position of the Campa-nianeMaastrichtian boundary in a 10 m thick interval at 330e320 m. The choice of tie-points between Hole 762C and Stevns-1allows a precise age-calibration.
4.4. Petrophysical logs
Downhole logging on location included GR, spectral GR, induc-tion, conductivity, density, p-wave velocity and temperature
Fig. 8. Selected dinoflagellates and acritarchs from the Stevns-1 core. All figures are at the sslide id (GEUS palynology preparation number), slide number and EF coordinates. A, ArARY19273/2, L35(4). C, Alterbidinium acutulum, AMF19383/2, J43(0). D, Impagidinium rigidARY19268/2, W35(0). F, Isabelidinium cooksoniae, 75.04 m, ARY19267/2, P43(0). G, HystrichosARY19265/2, V47(4). I, Palaeostomocystis reticulata, 339.88 m, ARY19275/2, X35(1), highARY19269/2, V35(0), high focus on ventral surface. L, same specimen as K, sectional focus.
measurements (Stemmerik et al., 2006). In addition detailedspectral GR and density logs were measured with a 1 cm/minutespeed at the laboratory of the Geological Survey of Denmark andGreenland (GEUS; Stemmerik et al., 2006. The GR log is useful toidentify and characterise the more marly intervals and has beenused for correlation of lithostratigraphic units between boreholes(Fig. 7; e.g. Surlyk et al., 2010a). The P-wave velocity log has beenused for tying the core to the reflection seismic data and to buildinga velocity model for the chalk (Nielsen et al., 2011). The conduc-tivity and temperature logs have been used in a groundwater study(Bonnesen et al., 2009), but do not add to the understanding of thechalk lithology. Scanning of the newly drilled and still wet coresusing a medical scanner (Computed Tomography, from hereontermed CT-scan) has allowed identification of subtle changes infacies and grain size (Rasmussen and Surlyk, 2012).
The Stevns-1 GR log shows slowly upwards increasing values inthe lowest part of the borehole below the Mandehoved Formation(450e438 m) and in the lower part of Flagbanke Member (Man-dehoved Formation, 438e394 m). Then follows a stepwise increaseto the highest values found in the borehole (394e350 m), corre-sponding to the high abundance of marl layers in the BoesdalMember (Mandehoved Formation), which is characterised by anumber of distinct peaks on the log. The log values then graduallydecrease upwards (350e311 m) to the lowest value found in theMøns Klint Formation (311e105m). The low values persist until thebase of the cyclic chalkemarl beds of the Rørdal Member (MønsKlint Formation), where the values increase strongly and show asuccession of peaks (105e76 m). Above this level the values againfall to a low level but tend to be more variable in the SigerslevMember (Møns Klint Formation; 76e15 m). There is a peak in thetop of the uppermost Maastrichtian Højerup Member. The marl-rich Mandehoved Formation and the Rørdal Member of the MønsKlint Formation are also easily recognisable on the velocity log asintervals of very high frequency variations between high and low P-wave velocities, reflecting the alternations between lower velocitymarl and higher velocity, slightly cemented marly chalk in thesemembers.
4.5. Reflection seismic profiles
A series of reflection seismic lines were recorded offshore andparallel to the coastal cliff of Stevns Klint. The lines are mainly NeSand EeW oriented, and a few are SWeNE oriented (Lykke-Andersen and Surlyk, 2004). The data quality is excellent with anestimated resolution of 10 m in the upper part, deterioratingdownwards to a resolution of about 30 m. Seven seismic sequences(1�7, from below) were recognised and Stevns-1 penetrates allsequences down into the uppermost part of sequence 2 (Fig. 10). Anonshore reflection seismic line was recorded between Stevns-1 and-2. The combined reflection and refraction seismic data haveimproved the understanding of the link between lithology andseismic reflectivity of the chalk.
4.6. Refraction seismic profile
Data from a 7.5 km long NeS oriented refraction seismic sectionroughly between but slightly west of a line connecting Stevns-1 and-2 have resulted in a four layer velocity model for the Chalk Group
ame scale except M. Scale bars in A and M. Species name is followed by sample depth,eoligera coronata, 144.65 m, ARY19271/2, P32(0). B, Trithyrodinium evittii, 310.20 m,aseptatum, 219.64 m, AMF19382/2, O51(0). E, Cassiculosphaeridium? tocheri, 91.04 m,phaeropsis perforata, 144.65 m, ARY19271/2, H32(2). H, Palynodinium grallator, 30.12 m,focus. J, same specimen as I, sectional focus. K, Microdinium carpentierae, 115.26 m,M. Palaeocystodinium golzowense, 190.55 m, AMF19381/2, U33(3).
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256244
Fig. 10. Reflection seismic section with position of the Stevns-1 and -2 boreholes indicated. Stevns-1 penetrated seismic sequences from sequence 7 and down into the uppermostpart of sequence 2. Modified from Lykke-Andersen and Surlyk (2004) and Rasmussen and Surlyk (2012).
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 245
in the area (Nielsen et al., 2011). Average velocities increase from2.2 km/s in the upper 70 m to 2.4 km/s in the 70e270 m interval,3.1 km/s from 270 m down to 610 m, and 3.9e4.1 km/s from 610 mdown to the base of the Chalk Group at approximately 860 m(Nielsen et al., 2011). The velocity layering reflects lithologicalchanges in the chalk succession; the boundary at 70 m reflects thedownward transition from pure chalk of the Sigerslev Member tointerbedded marl and chalk of the Rørdal Member, and theboundary at 270 m is interpreted to reflect the downward transi-tion of relatively pure chalk of the Hvidskud Member, lower MønsKlint Formation to the interbedded chalk and marl of the under-lying Mandehoved Formation.
4.7. Lithostratigraphy
The upper CampanianeMaastrichtian succession is 443.3 mthick and belongs to the poorly named Chalk Group of Deegan and
Fig. 9. Selected dinoflagellates and acritarchs from the Stevns-1 core. All figures are to theOdontochitina operculata, 434.87 m, AMF19388/2, X18(4). B, Subtilisphaera sp. 2 of MarhAMF19388/2, Q28(0). D, Samlandia mayii, 310.20 m, ARY19273/2, N48(2). E, Xenikoon sp. Anarvonensis, 394.93 m, ARY19278/3, T42(1). G, Eatonicysta hapala, 279.84 m, AMF19386/2pelagica, 23.17 m, ARY19264/2, Y21(2). J, Montanarocysta aemiliana, 352.28 m, YD19092/2,
Scull (1977). A place name ismissing and ‘chalk’ is the English namefor a rock type. In other languages it would have to be translated. Itis thus termed ‘Schreibkreide-Gruppe’ in a paper written inGerman by Niebuhr et al. (2007). In Danish it would be ‘SkrivekridtGruppe’ and in French ‘Groupe de la Craie Blanche’.
In Denmark only the upper part of the group has previouslybeen lithostratigraphically subdivided (Troelsen, 1955; Surlyk et al.,2006, 2010a). The top of the chalk succession exposed at StevnsKlint was tentatively referred to the Tor Formation of the North Seaby (Surlyk et al., 2006, p. 5), but it was stated that ‘It is possible thatfuture work will lead to the definition of a new formation for themore shallow marine, partly benthos-rich Maastrichtian chalk ofeastern Denmark’. In the present study, the upper CampanianeMaastrichtian chalk of Stevns-1 is subdivided into two new for-mations and six members, three of which are new; use of the TorFormation in the Danish Basin is herewith discontinued. The lowest18 m of the core (456.1e438 m) is not included in the new scheme
same scale except A. Scale bars in A and I. Data following species name as in Fig. 8. A,einecke (1992), 190.55 m, AMF19381/2, P35(4). C, Areoligera senonensis, 434.87 m,of Foucher and Robaszynski (1977), 144.65 m, ARY19271/2, F34(3). F, Samlandia car-
, F26(0). H, Neonorthidium perforatum, 144.65 m, ARY19271/3, S47(3). I, ThalassiphoraJ53(2).
Maa
stric
htia
nC
ampa
nian
Rügen
lower
middle
upper
Hemmoor
Reitbrook
Kjølby-gaard
Hvidskud
Rørdal
Sigerslev
Højerup
Hod Chalk 4 Unit Ommelanden Kronsmoor
unnamed
Møns Klint
Mandehoved
Tor TorTor
equivalentChalk 5 Unit
Flagbanke
Boesdal
Mackerel
Danish Basin
Formation Member
NorwegianNorth Sea
Formation
UK North Sea
DanishNorth Sea
DutchNorth Sea
ationmroFationmroF Member
Northern GermanyStage
Fig. 11. Tentative correlations with the lithostratigraphy of the eastern Danish Basin described here and lithostratigraphic schemes for the Norwegian (Isaksen and Tonstad, 1989),UK (Johnson and Lott, 1993), Danish (Lieberkind et al., 1982) and Dutch (Van Adrichem Boogaert and Kouwe (1994) North Sea Sectors, and northern Germany (Niebuhr et al., 2007).
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256246
and forms the top of an unnamed formation. The lithostratigraphicunits are described below in ascending order and tentative corre-lations with lithostratigraphic schemes in the Norwegian, UK,Danish and Dutch North Sea Sectors and northern Germany areshown in Fig. 11.
4.7.1. Unnamed formationThe lowest 18 m (456.1e438 m) of the core comprise mainly
pure chalk with a few thin conglomerates. The lower boundary ofthis formation is not known. Refraction seismic data indicate adownwards jump to higher seismic velocity, probably reflecting ahigher clay content at a depth of 610 m (Nielsen et al., 2011), andthis level is tentatively regarded as the base of the unnamed for-mation. In this case the formation is 172 m thick. The cored top partbelongs to the upper Campanian, the nannofossil UC15eBP subzoneand the Hystrichokolpoma gamospina dinoflagellate zone of Slimani(2001, 2011; Figs. 2, 3).
Correlations: the formation is tentatively correlated with themiddle Hod Formation of the Norwegian Sector, the middleMackerel Formation of the UK North Sea Sector, the OmmelandenFormation of the Dutch Sector, and the upper Dägelingen Forma-tion of northern Germany (see Lieberkind et al., 1982; Isaksen andTonstad, 1989; Johnson and Lott, 1993; Van Adrichem Boogaert andKouwe, 1994; Niebuhr et al., 2007, and Surlyk et al., 2003, for anoverview).
4.7.2. Mandehoved FormationNew formationName: after a cliff locality at Stevns Klint, situated close to theStevns-1 borehole (Fig. 1B).Type section: the Stevns-1 core from 438 to 309 m (Figs. 2, 7).
Reference section: the Stevns-2 core from the base at 350.6 m to244.2 m.Lithology: this formation consists of cyclically alternating chalk,marly chalk and marl beds (Rasmussen and Surlyk, 2012). Thelithological differences between marly and pure chalk are barelyvisible in the dry core but water wetting or oil impregnation en-hances the visibility. Themarly chalk beds are light grey andmainlyabout 50 cm thick but may reach a thickness up to about 1 m; thechalk beds are in general somewhat thicker. Distinct, clearlyobservable grey to dark-grey centimetre-thick marl layers occurthroughout the succession mainly in the middle part of the verylight grey marly chalk beds thus highlighting the cyclical pattern.Small porcellanite nodules occur scattered and early diageneticcelestite nodules are present throughout the formation (Madsenand Stemmerik, 2009). The main difference between the Flag-banke and Boesdal Members defined below is that the latter con-tains abundant intraclast conglomerates, and the abundance ofmarl layers is much higher as clearly revealed by the GR log (Fig. 2).Boundaries: the lower boundary is placed at 438 m at the base ofthe lowest distinct marl layer, coinciding with a marked peak in theGR log. The upper boundary is placed at 309 m at the top of theuppermost distinctive marly chalk bed a few metres above thehighest intraclast conglomerate; this coincides with an upwardschange from high to lower values on the g-ray log and less markedrhythmicity in the log pattern.Thickness: 129 m in Stevns-1. The uppermost 106.4 m of the for-mation are cored in Stevns-2.Distribution: only known from Stevns-1 and -2. A less marlycorrelative occurs in the lower part of Rørdal-1.Chrono- and biostratigraphy: upper Campanianelower lowerMaastrichtian, part of the spinosaesubtilis brachiopod zone (Surlyk,
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 247
1984), the UC16a-bBP, UC16cBP and UC16dBP nannofossil subzones(Thibault et al., 2012a), and the Hystrichokolpoma gamospina, Are-oligera coronata and Samlandia mayii dinoflagellate zones ofSlimani (2001, 2011).Subdivisions: The formation is subdivided from below into theFlagbanke and Boesdal Members.Correlations: the formation is correlated with the upper Hod For-mation of the Norwegian North Sea Sector, upper Mackerel of theUK Sector, upper Ommelanden of the Dutch Sector, and KronsmoorFormation of northern Germany (see Lieberkind et al., 1982;Isaksen and Tonstad, 1989; Johnson and Lott, 1993; Van AdrichemBoogaert and Kouwe, 1994; Niebuhr et al., 2007; Van der Molenand Wong, 2007; and Surlyk et al., 2003, for an overview).
4.7.2.1. Flagbanke Member. New memberName: after the locality of Flagbanke at Stevns Klint, situated closeto the Stevns-1 borehole (Fig. 1B).Type section: the Stevns-1 core from 438 to 394 m.Reference section: the Stevns-2 core from the base at 350.6 m to314.65 m.Lithology: alternating, mainly metre-thick beds of white chalk andthinner marly chalk. The marly chalk beds in most cases includedarker, sharp-bounded millimetre-to-centimetre thick marl layers(Fig. 5B). A few scattered thin intraclast conglomerates occur.Macrofossils are generally scarce but inoceramid bivalve shells areabundant in the 425e400 m interval (Fig. 5B). The member istotally bioturbated and is dominated by the trace fossils Zoophycosand Chondrites with a few occurrences of Thalassinoides. Stylolitesoccur throughout, and pyrite is observed in the 425e405 m inter-val. Small, early diagenetic celestite nodules are most abundant inthe upper part of the unit (Madsen and Stemmerik, 2009). The GRlog shows slowly increasing values from the base and upwards witha prominent positive excursion at about 437 m and a negative at410 m.Boundaries: the lower boundary is placed at 438 m at the base ofthe first distinct marl layer associated with a peak on the GR log.The upper boundary is placed at 394m at the incoming of abundantintra-chalk conglomerates, characterising the overlying BoesdalMember. This is approximately 15 m below the onset of markedhigh GR values in the upper Mandehoved Formation (Figs. 2, 7).Thickness: 44 m in Stevns-1 and 36 m in Stevns-2.Distribution: only known from Stevns-1 and -2.Chrono- and biostratigraphy: upper Campanian, the UC16a-bBP
nannofossil subzones (Thibault et al., 2012a), the Hystrichokolpomagamospina and Areoligera coronata dinoflagellate zones of Slimani(2001, 2011).Correlations: lower Kronsmoor Formation of northern Germany(see Niebuhr et al., 2007).
4.7.2.2. Boesdal Member. New memberName: after the quarry where the Stevns-2 borehole was drilled(Fig. 1B).Type section: the Stevns-1 core from 394 to 309 m.Reference section: the Stevns-2 core from 314.65 to 244.2 m.Lithology: themember is characterised by alternating decimetre-to-metre thick beds of chalk, marly chalk and marl, forming acontinuation of the cyclicity seen in the underlying FlagbankeMember, but the cycles are more regular and the marly chalk bedsare much thicker compared to the underlying member (Fig. 5A).This is clearly revealed by the higher values in the GR log. Bedboundaries are gradational. Millimetre-to-centimetre thick darkand sharp-bounded marl layers occur in the middle of many marlychalk beds. Another characteristic feature is the great abundance ofmillimetre-to-metre thick intraclast conglomerates which occurthroughout the member (Fig. 6A). The clasts are subrounded to
angular within a single bed but their shape varies from bed to bed.Macrofossil remains of echinoderms, bivalves, including inocer-amids, sponges and foraminifers occur throughout. Millimetre-thick laminae of skeletal fragments of mainly foraminifers andechinoderms occur from the middle of the member and upwardswith increasing abundance. The trace fossil assemblages are rela-tively diverse and Thalassinoides dominates throughout, associatedwith less common Zoophycos, Chondrites and Taenidium. Scatteredoccurrences of porcellanite nodules are present.Boundaries: the lower boundary is defined by the lowest prominentintraclast conglomerate at 394 m, where the GR values start toincrease, reflecting the upwards increasing content of clay. Theupper boundary is placed at 309 m a few metres above the up-permost conglomerate and at the uppermost high GR reading.Thickness: 85 m in Stevns-1 and 70.45 m in Stevns-2.Distribution: only known from Stevns-1 and -2.Chrono- and biostratigraphy: upper Campanian, CampanianeMaastrichtian boundary interval and lower Maastrichtian, part ofthe spinosaesubtilis brachiopod zone, the UC16a-bBP (uppermostpart) UC16cBP and lower half of UC16dBP nannofossil subzones(Thibault et al., 2012a), and the Samlandia mayii dinoflagellate zoneof Slimani (2001, 2011).Correlations: upper Kronsmoor Formation of northern Germany(see Niebuhr et al., 2007).
4.7.3. Møns Klint FormationNew formationName: after the coastal cliffs on the island of Møn where chalkbelonging to the formation is beautifully exposed in thrust sheetsformed by glacial tectonics (Fig. 1A).Type section: the Stevns-1 core from 309e12.8 m.Reference section: the Stevns-2 core from 244.2 m to 7.83 m basedon nannofossil and lithological evidence. A 23 cm thick sectionacross the boundary was not cored.Lithology: at the type section the Møns Klint Formation consists ofcyclically alternating chalk and slightly marly chalk beds of theHvidskud Member overlain by the Rørdal Member, which is char-acterised by pronounced chalk-marl cyclicity (Surlyk et al., 2010a),followed by almost pure chalk of the Sigerslev Member, andbryozoan-rich chalk of the Højerup Member (Surlyk et al., 2006).Small porcellanite nodules occur locally up to about 200 m; abovethis level there are abundant nodules of black flint (Madsen andStemmerik, 2010). Celestite nodules similar to those found in theunderlying Mandehoved Formation are most abundant between210e170 m, but appear as scattered occurrences up to the lowerpart of the Sigerslev Member at approximately 60 m (Madsen andStemmerik, 2009).Boundaries: the lower boundary is placed at the transition fromchalk with numerous intraformational conglomerates, a relativelyhigh clay content, and pronounced cyclicity to relatively pure chalk.The top of the formation is rather complex as it is overlain by thethin dark clay of the Fiskeler Member, or the Cerithium LimestoneMember of the lowermost Danian Rødvig Formation, or directly bybryozoan limestone of the lower Danian Stevns Klint Formation(Surlyk et al., 2006; figs. 2, 7, 9, 18).Thickness: 296.2 m in Stevns-1, 236.37 m in Stevns-2, top 9.2 m inTune-1, top 20.5 m in Tuba-13, top 13.2 m in Solrød-2 (all belongingto nannofossil zoneUC20dBP) and top 221 m in Karlslunde-1(belonging to nannofossil zone UC20b/cdBP) (Sheldon, GEUS, un-published data). ‘Top’ means that the formation was not fullypenetrated in the four latter boreholes.Distribution: the formation is known from outcrops at Møns Klint,Stevns Klint and Karlstrup quarry in eastern Denmark, and from theRørdal quarry and numerous small quarries south of Aalborg innorthern Jylland. It is also known from Stevns-1, Stevns-2, Tune-1,
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256248
Karlslunde-1, Solrød-2 and Tuba-13a in eastern Denmark and froma number of boreholes south of Aalborg and south of Copenhagen(Surlyk, 1984; Nielsen and Jørgensen, 2008; Surlyk et al., 2010a,b;Sheldon, GEUS, unpublished data).Subdivisions: the formation is subdivided from below into theHvidskud, Rørdal, Sigerslev and Højerup Members. An additional,very thin member, the Kjølby Gaard Marl Member, is known fromthe uppermost Maastrichtian in the type area of this member innorthern Jylland and from boreholes in the Køge Bugt area imme-diately to the north of Stevns (Larsen, 1998), but has not beenidentified in the Stevns boreholes.Chrono- and biostratigraphy: Maastrichtian. The upper spinosaesubtilis, subtilisepulchellus, pulchellusepulchellus, pulchelluseten-uicostata, tenuicostataesemiglobularis, semiglobularisehumboldtiiand humboldtiiestevensis brachiopod zones (Surlyk, 1984), theUC16dBP (upper half), UC17BP, UC18BP, UC19BP, UC20aBP, UC20b�cBP,and UC20dBP nannofossil zones (Thibault et al., 2012b), and theMembranilarnacia liradiscoides, Pervosphaeridium tubuloaculeatum,Deflandrea galeata and Hystrichostrogylon coninckii dinoflagellatezones of Slimani (2001, 2011) and the Triblastula utinensis zone tothe Palynodinium grallator zones of Schiøler and Wilson (1993) andHansen (1977), respectively.Correlations: the Chalk 5 unit in the Danish North Sea Sector, the TorFormation in the Norwegian and UK Sectors, a Tor Formationequivalent in the Dutch Sector, and the Hemmoor and ReitbrookFormations in northern Germany (see Lieberkind et al., 1982;Isaksen and Tonstad, 1989; Johnson and Lott, 1993; Van AdrichemBoogaert and Kouwe, 1994; Niebuhr et al., 2007; Van der Molenand Wong, 2007; Surlyk et al., 2003, for an overview).
4.7.3.1. Hvidskud Member. New memberName: after a glacial thrust sheet in the southern part of the coastalcliff, Møns Klint (Surlyk, 1972, 1984; Surlyk and Birkelund, 1977).Type section: the Stevns-1core, 309e105 m.Reference sections: the Stevns-2 core (244.2e118.22 m), and theglacial thrust sheets Hvidskud, Hundefangsklint, Lille Stejlebjergand Store Stejlebjerg at Møns Klint (Surlyk, 1984).Lithology: in Stevns-1, the member comprises alternating beds ofwhite chalk and darker slightly marly chalk. The white chalk bedsare thicker than in any other part of the core. The lowest 74 m ofthe member (309e235 m) has a low content of body fossils witha gradual upward increase in thin laminae of skeletal fragments.This part has a relatively high diversity of trace fossils withThalassinoides, Chondrites and Zoophycos being representedthroughout; it is rich in stylolites and a few porcellanite nodulesalso occur.
In the overlying part of the member from 235 m to the base ofthe Rørdal Member at 105 m thin skeletal laminae are abundant(Fig. 6B). Porcellanite nodules occur in the lower part from 235 mand upwards, and flint nodules occur from 197 m and are commonin the upper part of the core (Madsen and Stemmerik, 2010). Bodyfossils comprising echinoids, bivalves, including inoceramids andsponges occur throughout the member and bryozoans and fora-minifers are seen at a few levels in the upper part. Inoceramid bi-valves are abundant, especially from 235e205 m. The trace fossilassemblages are diverse in the upper 130 m of the member and aredominated by Thalassinoides, Zoophycos and Chondrites (Fig. 4A)Stylolites occur regularly from the base of the member and up-wards to 160 m; they are absent above this level.
The member is rich in bands of flint nodules at the sections atMøns Klint which also contains a thin incipient hardground (Surlyk,1972; Surlyk and Birkelund, 1977).Boundaries: The lower boundary is placed at 309 m where themarly chalk of the Mandehoved Formation is overlain by purerchalk of the Møns Klint Formation. The upper boundary is placed at
105 m at the base of a thick marly chalk bed forming the basal partof the overlying cyclic chalk-marl succession of the Rørdal Member,corresponding to a marked increase in GR values.Thickness: 204 m, 309e105 m in the Stevns-1 core, and 125.98 m,244.2e118.22 m in the Stevns-2 core.Distribution: the member is known from Stevns-1 and -2, and theglacial thrust sheets Hvidskud, Hundefangsklint, Lille Stejlebjergand Store Stejlebjerg at Møns Klint. The lower part of Karlslunde-1from 210.4 m and downward also belongs to this member.Chrono- and biostratigraphy: lower Maastrichtian and lower upperMaastrichtian. The upper spinosaesubtilis, subtilisepulchellus andlower pulchellusepulchellus brachiopod zones, the UC16dBP (upperhalf), UC17BP, UC18BP, UC19BP, UC20aBP and UC20b�cBP (lowermostpart) nannofossil zones (Thibault et al., 2012a), and the Mem-branilarnacia liradiscoides, Pervosphaeridium tubuloaculeatum andDeflandrea galeata dinoflagellate subzones of Slimani (2001) andthe Triblastula utinensis dinoflagellate zone of Schiøler and Wilson(1993).Correlations: the Rügen Member of the Hemmoor Formation innorthern Germany (see Niebuhr et al., 2007).
4.7.3.2. Rørdal Member (Surlyk et al., 2010a). Name: after theRørdal quarry in Aalborg, northern Jylland (Fig. 1A).Type section: Rørdal quarry (Fig. 2A in Surlyk et al., 2010a).Reference sections: Stevns-1 (105e76 m), Stevns-2 (118.22e88.25 m) and Karlslunde-1 (201.4e165 m).Lithology: the Rørdal Member in Stevns-1 consists of grey marlychalk without any white chalk intercalations. A few darker marllayers are characterised by distinctive peaks on the GR log, whichshows a sharp increase at the base of themember, followed by 10 or11 peaks, and decreasing steeply at the upper boundary. Flint oc-curs as nodules in the lower part and as bands in the upper part.The trace fossil assemblages are totally dominated by Zoophycos,Chondrites and Thalassinoides but change at the upper boundary toChondrites and Thalassinoides. Scattered body fossils include bryo-zoans, echinoderms, bivalves, sponges and foraminifers. Thestratigraphically highest inoceramid bivalve is found at about100 m. A few thin skeletal laminae also occur.Boundaries: the lower boundary is placed at 105 m, where alter-nating beds of pure chalk and slightly marly chalk of the HvidskudMember are overlain by grey marly chalk showing high GR valueswith a pronounced rhythmicity. The upper boundary is placed at76 m where the grey marly chalk of the Rørdal Member is overlainby pure chalk of the Sigerslev Member. The upper boundary cor-responds to the boundary between velocity layers 1 and 2 inNielsen et al. (2011). This is higher than the boundary tentativelyproposed by Surlyk et al. (2010a) as detailed logging indicates thatthe cyclic interval continues upwards from the level originallypicked as the upper boundary in Stevns-1.Thickness: 29 m (105e76 m) in Stevns-1, 30 m in Stevns-2, 36 m inKarlslunde-1 and 10 m in the Rørdal quarry.Distribution: the Rørdal Member is known from the Rørdal quarry, anumber of boreholes south of Aalborg, Stevns-1 and -2, Karlslunde-1 and Stenlille boreholes south and west of Copenhagen (Nielsenand Jørgensen, 2008; Surlyk et al., 2010a). At the time of writingit is exposed in the deepest part of the Sigerslev Quarry. Formerly, itwas exposed in the LimhamnQuarry south ofMalmø in SWSwedenin the easternmost part of the Danish Basin in a succession withmounded bedding, similar to the lower Sigerslev Member, which,however, is devoid of marl layers. It comprised 10e12 marl layers,0.1e0.3 m thick, with a spacing of 0.75e2.00 m, and forms the topof the Maastrichtian (Brotzen, 1959; Surlyk, 1969).Chrono- and biostratigraphy: upper Maastrichtian. The lower semi-globularisehumboldtii brachiopod zone (Surlyk, 1984), the UC20b-cBP nannofossil zone (Thibault et al., 2012a), and the Deflandrea
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 249
galeata dinoflagellate zone of Slimani (2001). This interval corre-sponds almost exactly to the entire Isabelidinium cooksoniae zone ofSchiøler and Wilson (1993).Correlations: the member is tentatively correlated with the lowerReitbrook Formation (termed “Unteres Reitbrook-Member” inNiebuhr et al., 2007) and seismic sequence CK9 in the Dutch NorthSea Sector (see Van der Molen and Wong, 2007).
4.7.3.3. Sigerslev Member (Surlyk et al., 2006). Name: after a quarryat Stevns Klint.Type section: Sigerslev quarry (Surlyk et al., 2006; Anderskouv et al.,2007).Reference section: Stevns-1, Stevns-2, Karlslunde-1 and Stenlilleboreholes.Lithology: the Sigerslev Member in the Stevns-1 core consists ofwhite chalk with only a few intercalations of marly chalk. Flintnodules and bands occur throughout. The lower part is relativelyrich in benthic fossils and passes upwards into benthos-poor chalk(Surlyk et al., 2006; Anderskouv et al., 2007). The trace fossil as-semblages are dominated from the base and upwards by Zoophycos,Chondrites and Thalassinoides followed by Zoophycos and Thalassi-noides, and at the top by Zoophycos alone as in outcrop at StevnsKlint (Surlyk et al., 2006). The GR log shows low values throughoutwith an isolated peak at about 70 m.Boundaries: the lower boundary is not exposed in the type area, thecoastal cliff Stevns Klint (Surlyk et al., 2006). In the Stevns-1 and -2boreholes it is placed where pure white chalk of the memberoverlies rhythmic chalk-marl of the Rørdal Member. The upperboundary is placedwherewhite benthos-poor chalk of thememberis overlain by bryozoan-rich chalk of the Højerup Member. In thecoastal cliff of Stevns Klint this boundary is placed at the upper oftwo incipient hardgrounds (Surlyk et al., 2006).Thickness: 61 m (76e15 m) in Stevns-1, 78.27 m (88.25e10.01 m)in Stevns-2; the upper c. 30 m of the member is exposed in theStevns Klint coastal section and the Sigerslev quarry (Surlyk et al.,2006).Distribution: the Sigerslev Member is recognised in outcrop atStevns Klint especially in the northern part of the cliff, in Stevns-1and -2, and in scattered small quarries south of Aalborg in northernJylland.Chrono- and biostratigraphy: upper Maastrichtian. Belemnella kazi-miroviensis belemnite zone, probably reaching down into theBelemnitella junior zone (Christensen, 1979, 1997), the stevensisechitoniformis brachiopod zone, probably reaching down into thehumboldtiiestevensis zone (Surlyk, 1984), the Nephrolithus frequenscoccolith zone (Perch-Nielsen, 1979a,b), the uppermost UC20b-cBP
and UC20dBP nannofossil zones (Thibault et al., 2012a), theDeflandrea galeata (subzone b) and Hystrichostrogylon coninckiidinoflagellate zones of Slimani (2001), and the Palaeocystodiniumdenticulatum, Hystrichosphaeropsis borisii and Palynodinium gralla-tor dinoflagellates zones of Hansen (1977) and Schiøler and Wilson(1993).Correlations: the member is tentatively correlated with the middleReitbrook Formation of northern Germany (termed “MittleresReitbrook-Member” in Niebuhr et al., 2007) and seismic sequenceCK9 in the Dutch North Sea Sector (see Van der Molen and Wong,2007).
4.7.3.4. Kjølby Gaard Marl Member (Troelsen, 1955). Name: thismember was named after a small quarry at the farm of Kjølby Gaardin northern Jylland.Type section: a now abandoned quarry at Kjølby Gaard, northernJylland (Fig. 1; Troelsen, 1955).Lithology: the member was described as a thin marl bed with thinlaminae of slightly contorted chalk (Troelsen, 1955).
Boundaries: the lower boundary is placed at the transition fromwhite chalk to marl and the upper boundary is placed where themarl passes into white chalk. Both boundaries are gradational.Thickness: 35 cm at the type section and 20 and 50 cm at otherlocalities in northern Jylland (Troelsen, 1955).Distribution: at the type locality it occurs 11.5 m below the KePgboundary; small quarries in northern Jylland (Erslev, Nye Kløv,Vokslev, Dania), boreholes in the Danish Basin (Tune-1, Tuba-13,Solrød-2; Sheldon, GEUS, unpublished data ) and a probablecorrelative is recognised in the North Sea Basin (M-10X, E-5X,Nana-1XP, N-22X; Sheldon et al., 2010).Chrono- and biostratigraphy: upper Maastrichtian. The Belemnellakazimiroviensis belemnite zone, the stevensisechitoniformisbrachiopod zone (Surlyk, 1984), the UC20dBP nannofossil zone(Thibault et al., 2012a), the Hystrichostrogylon coninckii (subzone b)dinoflagellate zone of Slimani (2001) and the Palynodinium grallator(Thalassiphora pelagica subzone) dinoflagellate zone of Hansen(1977).
The member has a rich foraminifer fauna with unusual warmwater species such as Contusotruncana contusa (Cushman). Themember is absent in the Stevns cores but it is remarkable that itsage seems to correspond to the hiatus between the Sigerslev andthe overlying Højerup Member. This hiatus was identified as amajor sequence boundary by Surlyk (1997), separating deep-waterchalk of the upper Sigerslev Member from the much shallowerwater bryozoan-rich mound-bedded chalk wackestone of theHøjerup Member. It also separates pure chalk of the SigerslevMember from bryozoan-rich chalk of the HøjerupMember in Tune-1 (M. Ahlborn, pers. comm., 2012).
4.7.3.5. Højerup Member (Surlyk et al., 2006). Name: after thevillage of Højerup close to the cliff of Stevns Klint� the most visitedsite at the cliff.Type section: Stevns Klint below Højerup Old Church (Surlyk et al.,2006).Reference section: Stevns-1.Lithology: the Højerup Member in the Stevns-1 core is a bryozoanchalk wackestone with a significantly larger grain size than the un-derlying members. Flint occurs as nodule bands. The member is richin benthic fossils, notably bryozoans. The trace fossil assemblage isdominated by Thalassinoides. The GR trace shows a peak at the top ofthemember. In the southern part of the cliff exposure themember isthicker than in Stevns-1 and consists of bryozoan wackestonedeposited in small asymmetrical, bryozoan-rich biogenic mounds(Surlyk, 1997; Larsen and Håkansson, 2000; Surlyk et al., 2006).Layers of flint nodules associated with Thalassinoides burrow hori-zons characterise the gently dipping northern flank of the mounds,and small-scale slump, slide and debris flow deposits are occasion-ally seen on the southern mound flanks (Surlyk, 1972). The upper c.30 cm of the mound crests are lithified and topped by a hardgrounddirectlyoverlainbybryozoan limestoneof the lowerDanianKorsnæbMember (Stevns Klint Formation). At Karlstrup Quarry, the membershowsundulatingmoundedbedding and is toppedbya thin nodular,slightly erosional hardground draped with a thin marl layer. Thislayer is not the basal Danian Fiskeler Member (Fish Clay in olderliterature) as suggested by Gravesen (1983) in spite of its positionoverlying the topMaastrichtianchalk, buta stratigraphically youngerlower Danian marl layer (Surlyk, 1972). It is overlain by lower andmiddle Danian bryozoan limestone of the Stevns Klint Formation,showing mounded bedding concordant with the Maastrichtian un-dulating mounds (Surlyk, 1969). The stratigraphic developmentacross the MaastrichtianeDanian boundary is, however, highly var-iable in various parts of the quarry (Gravesen, 1983).Boundaries: At the type locality, the lower boundary is placed at thetop of the upper of two incipient hardgrounds topping the pure
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256250
white benthos-poor chalk of the Sigerslev Member. It is placed atthe transition from benthos-poor to bryozoan rich chalk in Stevns-1and -2. The upper boundary is defined at the base of the thin blackto dark grey clay of the basal Danian Fiskeler Member and coincideswith the KePg boundary. The latter member is restricted to thetroughs between the topmost Maastrichtian mounds. It passesgradually upwards into the Cerithium Limestone Member whichoverlaps the Fiskeler Member at the margins of the troughs. Wherethe Fiskeler Member has wedged out, the boundary is placed at thebase of the Cerithium Limestone Member, or by a marked erosionalhardground at the base of the bryozoan limestone of the lowerDanian Stevns Klint Formation (See Fig. 4 in Surlyk, 1997; andFigs. 7 and 9 in Surlyk et al., 2006).Thickness: a total of 2.2 m (15e12.8 m) in Stevns-1 which wasdrilled over the crest of one of the bryozoan mounds outside one ofthe small Fiskeler basins. The basal Danian Fiskeler and CerithiumLimestoneMembers are thus not represented in the core. In the cliffexposure the member is up to 6 m thick beneath mound crests. Itthins gradually towards the north and has almost wedged out atKulstirenden (Surlyk et al., 2006).Distribution: themember is known from outcrop at Stevns Klint andKarlstrup quarry, and from the boreholes Stevns-1, Stevns-2(2.08 m, 10.01e7.93 m), Tuba-13, Solrød-2 and Tune-1.Chrono- and biostratigraphy: uppermost Maastrichtian. Top part ofthe Belemnella kazimiroviensis belemnite zone, the stevensisechi-toniformis brachiopod zone (Surlyk,1984), theNephrolithus frequenscoccolith zone (Perch-Nielsen, 1979a,b), the Pseudotextularia ele-gans foraminifer zone (Schmitz et al., 1992) and the uppermostMaastrichtian nannofossil zone UC20dBP (Thibault et al., 2012a).Correlatives: the upper Reitbrook Formation of northern Germany(termed “Oberes Reitbrook-Member” in Niebuhr et al. (2007, whostated that up to 0.9 m of this unit belongs to the Danian, whereasthe Højerup Members is uppermost Maastrichtian only) andseismic sequence CK10 in the Dutch North Sea Sector (see Van derMolen and Wong, 2007).
5. Conclusions
A holostratigraphic scheme is presented for the upper Cam-panian (pars)eMaastrichtian of eastern Denmark based on com-bined lithological and oxygen and carbon isotope data, nannofossiland dinoflagellate biostratigraphy, GR logs, and reflection andrefraction seismic profiles. Two new formations and three newmembers are defined here, and a lithostratigraphic scheme isproposed based on the fully cored Stevns-1 borehole, supple-mented with data from the Stevns-2, Karlslunde-1, Solrød-2, Tune-1 and Tuba-13 boreholes and from outcrops at Stevns Klint,Karlstrup quarry, Møns Klint and northern Jylland. The upperCampanianelowermost Maastrichtian Mandehoved Formation issubdivided into the Flagbanke and Boesdal Members, and theMaastrichtian Møns Klint Formation is subdivided into the Hvid-skud, Rørdal, Sigerslev, Kjølby Gaard Marl and Højerup Members.The cyclic Rørdal Member and the thin Kjølby Gaard Marl Membercan be traced regionally and are important markers in the rela-tively monotonous chalk succession. The lithostratigraphic unitshave with some reservation been correlated with lithostrati-graphic schemes of northern Germany, and the Danish, Norwe-gian, UK and Dutch North Sea sectors. The Stevns-1 boreholecontains one of the most expanded Maastrichtian successionsknown worldwide.
Acknowledgements
The study was funded by the Danish Natural Science ResearchCouncil and the Carlsberg Foundation, with additional funding
from Geocenter Danmark and the University of Copenhagen. PSacknowledges support from the Ministry of Science and Innovationprogrammes C050X905, Petroleum Source Rocks and Fluids andGNS Science’s Direct Crown Funded programme Global ChangeThrough Time, Biostratigraphy and Time Scales (GCT8). We aregrateful to Silke Voigt for information on the lithostratigraphy ofNorthern Germany and to journal reviewers Andy Gale and JonIneson for highly constructive reviews.
References
Anderskouv, K., Damholt, T., Surlyk, F., 2007. Late Maastrichtian chalk mounds,Stevns Klint, Denmark e combined physical and biogenic structures. Sedi-mentary Geology 200, 57e72.
Anderskouv, K., Surlyk, F., 2011. Upper Cretaceous chalk facies and depositionalhistory recorded in the Mona-1 core, Mona Ridge, Danish North Sea. GeologicalSurvey of Denmark and Greenland Bulletin 25, 1e60.
Anderskouv, K., Surlyk, F., 2012. The influence of depositional processes on theporosity of chalk. Journal of the Geological Society, London 169, 311e325.http://dx.doi.org/10.1144/0016-76492011-079.
Antonescu, E., Foucher, J.-C., Odin, G.S., Schiøler, P., Siegl-Farkas, A., Wilson, G.J.,2001. Dinoflagellate cysts in the CampanianeMaastrichtian succession ofTercis-les Bains (Landes, France), a synthesis. In: Odin, G.S. (Ed.), The Campa-nianeMaastrichtian Stage Boundary: characterisation at Tercis les Bains(France): correlation with Europe and other continents, IUGS Special Publica-tion (monograph) Series, 36; Developments in Palaeontology and StratigraphySeries, 19. Elsevier Science Publishers, Amsterdam, pp. 253e264.
Batenburg, S.J., Sprovieri, M., Gale, A.S., Hilgen, F.J., Hüsing, S., Laskar, J.,Liebrand, D., Lirer, F., Orue-Etxebarria, X., Pelosi, N., Smit, J., 2012. Cyclo-stratigraphy and astronomical tuning of the Late Maastrichtian at Zumaia(Basque country, Northern Spain). Earth and Planetary Science Letters 359e360, 264e278.
Batten, D.J., 1999. Small palynomorphs. In: Jones, T.P., Rowe, N.P. (Eds.), Fossil Plantsand Spores: modern Techniques. Geological Society, London, pp. 15e19.
Birkelund, T., 1957. Upper Cretaceous belemnites from Denmark. Biologiske Skrifterudgivet af Det Kongelige Danske Videnskabernes Selskab 9 (1), 1e69.
Bonnesen, E.P., Larsen, F., Sonnenborg, T.O., Klitten, K., Stemmerik, L., 2009. Deepsaltwater in Chalk of North-West Europe: origin, interface characteristics anddevelopment over geological time. Hydrogeology Journal 17, 1643e1663.
Brinkhuis, H., Schiøler, P., 1996. Palynology of the Geulhemmerberg Cretaceous/Tertiary boundary section (Limburg, SE Netherlands). Geologie en Mijnbouw75, 193e213.
Brotzen, F., 1959. On Tylocidaris species (Echinoidea) and the stratigraphy of theDanian of Sweden. Sveriges Geologiska Undersökning. Ser, C, Avhandlingar ochUppsatser, N: O 571, Årsbok 54, N: O. 2, 81.
Burnett, J., 1998. Upper Cretaceous. In: Bown, P.R. (Ed.), Calcareous NannofossilBiostratigraphy. Chapman and Hall/Kluwer Academic Publishers, London,pp. 132e199.
Christensen, W.K., 1979. Maastrichtian belemnites from Denmark. In: Birkelund, T.,Bromley, R.G. (Eds.), Symposium on the Cretaceous/ Tertiary boundary events; I,The Maastrichtian and Danian of Denmark. Univ. Copenhagen, Copenhagen,Denmark, pp. 108e114.
Christensen, W.K., 1997. The Late Cretaceous belemnite family Belemnitellidae:Taxonomy and evolutionary history. Bulletin of the Geological Society ofDenmark 44, 59e88.
Deegan, C.E., Scull, B.E., 1977. A proposed standard lithostratigraphic nomenclaturefor the Mesozoic of the central and northern North Sea. In: Finstad, K.G.,Selley, R.C. (Eds.), Mesozoic; northern North Sea symposium 1977 (MNNSS-77);proceedings, 25 pp.
Ekdale, A.A., Bromley, R.G., 1983. Trace fossils and ichnofabric in the Kjølby GaardMarl, uppermost Cretaceous, Denmark. Bulletin of the Geological Society ofDenmark 31, 107e119.
Esmerode, E.V., Lykke-Andersen, H., Surlyk, F., 2007. Ridge and valley systems in theUpper Cretaceous chalk of the Danish Basin: contourites in an epeiric sea. In:Viana, A.R., Rebesco, M. (Eds.), Economic and Palaeoceanographic Significanceof Contourite deposits, Geological Society, London, Special Publications, 276,pp. 265e282.
Fensome, R.A., Williams, G.L., 2004. The Lentin and Williams index of fossil Di-noflagellates. In: AASP Contributions Series (2004 edition) 42. American As-sociation of Stratigraphic Palynologists Foundation, Dallas, Texas, p. 909.
Foucher, J.C., Robaszynski, F., 1977. Microplankton des silex du Basin De Mons(Belgique) (Dinoflagellés Crétacés et Daniens). Annales de Paleontologie,Invertébrés 63, 19e58.
Gardin, S., Del Panta, F., Monechi, S., Pozzi, M., 2001. A Tethyan reference record forthe Campanian and Maastrichtian stages: the Bottaccione section (CentralItaly); review of data and new calcareous nannofossil results. In: Odin, G.S.(Ed.), The CampanianeMaastrichtian Stage Boundary. Characterization at Tercisles Bains (France) and correlation with Europe and other Continents, De-velopments in Palaeontology and Stratigraphy 19, pp. 745e757.
Gravesen, P., 1983. Maastrichtien/Danien grænsen i Karlstrup Kalkgrav(Østsjælland). Dansk Geologisk Forening, Årsskrift for 1982, 47e58.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 251
Hansen, J.M., 1977. Dinoflagellate stratigraphy and echinoid distribution in UpperMaastrichtian and Danien deposits from Denmark. Bulletin of the GeologicalSociety of Denmark 26, 1e26.
Husson, D., Galbrun, B., Laskar, J., Hinnov, L., Thibault, N., Gardin, S., Locklair, R.,2011. Astronomical calibration of the Maastrichtian (Late Cretaceous). EarthPlanet. Sci. Lett. 305, 328e340.
Ineson, J.R., Buchardt, B., Lassen, S., Rasmussen, J.A., Schiøler, P., Schovsbo, N.H.,Sheldon, E., Surlyk, F., 2006. Stratigraphy and palaeoceanography of upperMaastrichtian chalks, southern Danish Central Graben. Geological Survey ofDenmark and Greenland Bulletin 10, 9e12.
Isaksen, D., Tonstad, K., 1989. A revised Cretaceous and Tertiary lithostratigraphicnomenclature for the Norwegian North Sea. NPD Bulletin 5, 59.
Jeletzky, J.A., 1951. Die Stratigraphie und Belemnitenfauna des Obercampan undMaastricht Westfalens, Nordwestdeutschlands und Dänemarks sowie einigealgemeine Gliederungsprobleme der jüngeren borealen Oberkreide Eurasiens.Geologische Jahrbuch Beihefte 1, 142.
Johnson, H., Lott, G.K., 1993. Lithostratigraphic nomenclature of the UK North Sea.In: Knox, R.W.O.’B., Cordey, W.G. (Eds.), Cretaceous of the Central and NorthernNorth Sea, Lithostratigraphic Nomenclature of the UK North Sea 2. BritishGeological Survey, Nottingham, p. 169.
Kennedy, W.J., 1967. Burrows and surface traces from the Lower Chalk of southernEngland. Bulletin of the British Museum (Natural History), Geology 15, 125e167.
Kennedy, W.J., 1970. Trace fossils in the chalk environment. In: Crimes, T.P.,Harper, J.C. (Eds.), Trace Fossils. Seel House Press, Liverpool, pp. 263e282.
Larsen, N., Håkansson, E., 2000. Microfacies mosaics across latest Maastrichtianbryozoan mounds in Denmark. In: 11th International Bryozoology AssociationConference, pp. 272e281.
Larsen, O., 1998. Mapping of the Maastrichtian�Danian boundary in the coastalarea of Køge Bugt by gamma and resistivity logging. Bulletin of the GeologicalSociety of Denmark 44, 101e113.
Lauridsen, B.W., Surlyk, F., Bromley, R.G., 2011. Trace fossils of a cyclic chalk-marlsuccession; the upper Maastrichtian Rørdal Member, Denmark. CretaceousResearch 32, 194e202.
Liboriussen, J., Ashton, P., Tygesen, T., 1987. The tectonic evolution of the Fenno-scandian Border Zone in Denmark. Tectonophysics 137, 21e29.
Lieberkind, K., Bang, I., Mikkelsen, N., Nygaard, E., 1982. Late Cretaceous and Danianlimestones. In: Michelsen, O. (Ed.), Geology of the Danish Central Graben, SeriesB, 8. Geological Survey of Denmark, pp. 49e62.
Lykke-Andersen, H., Surlyk, F., 2004. The Cretaceous�Palaeogene boundary atStevns Klint, Denmark: Inversion tectonics or sea-floor topography? Journal ofthe Geological Society, London 161, 343e352.
Madsen, H.B., 2009. Microbial and burial induced silica diagenesis in UpperCretaceousePaleogene chalk in Denmark and the North Sea. PhD thesis. Uni-versity of Copenhagen, Denmark. Danmarks og Grønlands Geologiske Under-søgelse Rapport 2009/41, 33 pp.
Madsen, H.B., Stemmerik, L., 2009. Early diagenetic celestite replacement ofdemosponges in Upper Cretaceous (CampanianeMaastrichtian) chalk, Stevns,Denmark. Geology, 355e358.
Madsen, H.B., Stemmerik, L., 2010. Diagenesis of flint and porcellanite in theMaastrichtian chalk at Stevns Klint, Denmark. Journal of Sedimentary Research80, 578e588.
Marheinecke, U., 1992. Monographie der Dinocysten, Acritarcha and Chlorophytades Maastrichtium von Hemmoor (Niedersachsen). Palaeontographica B 227, 1e173.
Niebuhr, B., Hiss, M., Kaplan, U., Tröger, K.-A., Voigt, Sl, Voigt, T., Wiese, F.,Wilmsen, M., 2007. Lithostratigraphie der norddeutschen Oberkreide. Schrif-tenreihe der Deutschen Gesellschaft für Geowissenschaften 55, 136.
Nielsen, L., Boldreel, L.O., Hansen, T.M., Lykke-Andersen, H., Stemmerik, L., Surlyk, F.,Thybo, H., 2011. Integrated seismic analysis of the Chalk Group in easternDenmark e implications for estimates of post-depositional uplift in southwestScandinavia. Tectonophysics 511, 14e26.
Nielsen, K.S., Jørgensen, J.B., 2008. Lavpermeable horisonter i skrivekridtet e fase A.Miljøministeriet. Miljøcenter Aalborg, pp. 1e36.
Perch-Nielsen, K., 1979a. Calcareous nannofossil zonation at the Cretaceous/TertiaryBoundary in Denmark. In: Birkelund, T., Bromley, R.G. (Eds.), Symposium on theCretaceous/Tertiary boundary events; I, The Maastrichtian and Danian ofDenmark. Univ. Copenhagen, Copenhagen, Denmark, pp. 115e135.
Perch-Nielsen, K., 1979b. Calcareous nannofossils from the Cretaceous between theNorth Sea and the Mediterranean. Aspekte der Kreide Europas, IUGS series A 6,223e272.
Perch-Nielsen, K., 1985. Cenozoic calcareous nannofossils. Mesozoic calcareousnannofossils. In: Bolli, H.M., Saunders, J.B., Perch-Nielsen, K. (Eds.), PlanktonStratigraphy. Cambridge University Press, Cambridge, pp. 329e554.
Rasmussen, S.L., Surlyk, F., 2012. Facies and ichnology of an Upper Cretaceous chalkcontourite drift complex, eastern Denmark and the validity of contourite faciesmodels. Journal of the Geological Society, London 169, 435e447.
Schiøler, P., 1993. New species of dinoflagellate cysts from MaastrichtianeDanianchalks of the Danish North Sea. Journal of Micropalaeontology 12, 99e112.
Schiøler, P., Wilson, G.J., 1993. Maastrichtian dinoflagellate zonation in the DanField, Danish North Sea. Review of Palaeobotany and Palynology 78, 321e351.
Schiøler, P., Wilson, G.J., 1994. Glaphyrosphaera, a new dinoflagellate genus from theMaastrichtian of Denmark. Grana 33, 139e145.
Schiøler, P., Wilson, G.J., 2001. Dinoflagellate biostratigraphy around the Campa-nianeMaastrichtian boundary at its type section (Tercis Quarry, southwest
France). In: Odin, G.S. (Ed.), The CampanianeMaastrichtian stage Boundary:characterisation at Tercis les Bains (France): correlation with Europe and otherContinents, IUGS Special Publication (monograph) Series, 36; Developments inPalaeontology and Stratigraphy Series, 19. Elsevier Science Publishers, Amster-dam, pp. 221e234.
Schmitz, B., Keller, G., Stenvall, O., 1992. Stable isotope and foraminiferal changesacross the CretaceouseTertiary boundary at Stevns Klint, Denmark; argumentsfor long-term oceanic instability before and after bolide-impact event. Palae-ogeography, Palaeoclimatology, Palaeoecology 96, 233e260.
Schmid, F., Schulz, M.-G., Wood, C., 2004. The Maastrichtian sections of Hemmoorand Kronsmoor e retrospect, stocktaking and bibliography. Geologisches Jahr-buch A157, 11e22.
Schovsbo, N.H., Rasmussen, S.L., Sheldon, E., Stemmerik, L., 2008. Correlation ofcarbon isotope events in the Danish Upper Cretaceous chalk. Geological Surveyof Denmark and Greenland Bulletin 15, 13e16.
Schumacker-Lambry, J., 1977. Microfossiles végéteaux? planctoniques. In: Streel, M.,et al. (Eds.), Macro-et microfossiles végétaux dans le contexte litho- et bio-stratigraphique du SénonienePaléocène de la rive gauche de la Meuse au nordde Liège, Belgique. Field guide hand-out at Symposium’ Apport des techniquesrécentes en Palynologie. University of Liege, pp. 45e53.
Sheldon, E., 2006. Upper MaastrichtianeDanian nannofossils of the Danish CentralGraben and the Danish Basin: a combined biostratigraphicepalaeoecologicalapproach. Unpublished Ph.D. Thesis. University College London, London.
Sheldon, E., 2008. Upper CampanianeMaastrichtian calcareous nannofossilbiostratigraphy of the Stevns-1 borehole, Denmark. Journal of NannoplanktonResearch 30, 39e49.
Sheldon, E., Ineson, J., Bown, P., 2010. Late Maastrichtian warming in the BorealRealm: nannofossil evidence from Denmark. Palaeogeography, Palae-oclimatology, Palaeoecology 295, 55e75.
Sheldon, E., Gravesen, P., Nøhr-Hansen, H., 2012. Geology of the Femern Bælt areabetween Denmark and Germany. Geological Survey of Denmark and GreenlandBulletin 26, 13e16.
Slimani, H., 1995. Les dinokystes des Craies du Campanien au Danien à Halembaye,Turnhout (Belgique) et à Beutenaken (Pays-Bas): Biostratigraphie et systém-atique (unpublished PhD Thesis). Laboratorium voor Paleontologie, Rijksuni-versiteit Gent, Belgium, p. 540.
Slimani, H., 2001. Les kystes de dinoflagellés du Campanian au Danien dans la ré-gion de Maastricht (Belgique et Pays-Bas) et de Turnhout (Belgique): bio-zonation et corrélation avec d’autres régions en Europe occidentale. Geologicaet Palaeontogica 35, 161e201.
Slimani, H., 2011. Connecting the Chalk Group of the Campine Basin to the dino-flagellate cyst biostratigraphy of the Campanian to Danian in borehole Meer(northern Belgium). Netherlands Journal of Geosciences 90, 129e164.
Stemmerik, L., Surlyk, F., Klitten, K., Rasmussen, S.L., Schovsbo, N., 2006. Shallowcore drilling of the Upper Cretaceous chalk at Stevns Klint, Denmark. GeologicalSurvey of Denmark and Greenland Bulletin 10, 13e16.
Stenestad, E., 1971. Øvre Kridt i Rønde nr. 1 (307e1985 m) (English summary).Danmarks Geologiske Undersøgelse, 3. Rk., Nr. 39, 53e60.
Stenestad, E., 2005. Heterohelix dentata biozonen i boringen Rørdal-1, øvre nedreMaastrichtien, Nordjylland, Danmark. Geologisk Tidsskrift 1, 1e23.
Stoll, H.M., Schrag, D.P., 2001. Sr/Ca variations in Cretaceous carbonates: relation toproductivity and sea level changes. Palaeogeography, Palaeoclimatology,Palaeoecology 168, 311e336.
Surlyk, F., 1969. En undersøgelse over de articulate brachiopoder i det danskeskrivekridt (ø. Campanien og Maastrichtien) med en oversigt over skri-vekridtets sedimentologi og skrivekridthavets flora og fauna. Gold MedalThesis. University of Copenhagen, Unpublished, p. 319.
Surlyk, F., 1970. Die Stratigraphie des Maastricht von Dänemark und Nord-deutschland aufgrund von Brachiopoden. Newsletters on Stratigraphy 1, 7e16.
Surlyk, F., 1972. Morphological adaptations and population structures of the Danishchalk brachiopods (Maastrichtian, Upper Cretaceous). Biologiske Skrifter udgi-vet af Det Kongelige Danske Videnskabernes Selskab 19 (2), 68.
Surlyk, F., 1982. Brachiopods from the CampanianeMaastrichtian boundarysequence, Kronsmoor (NW Germany). Geol. Jb. A 61, 259e277.
Surlyk, F., 1984. The Maastrichtian Stage in NW Europe, and its brachiopod zona-tion. Bulletin of the Geological Society of Denmark 33, 217e223.
Surlyk, F., 1997. A cool-water carbonate ramp with bryozoan mounds: Late Creta-ceouseDanian of the Danish Basin. In: James, N.P., Clarke, J.D.A. (Eds.), Cool-water Carbonates, SEPM Special Publication 56, pp. 293e307.
Surlyk, F., Birkelund, T., 1977. An integrated stratigraphical study of fossil assem-blages from the Maastrichtian White Chalk of Northwestern Europe. In:Kaufman, E.G., Hazel, J.E. (Eds.), Concepts and Methods of Biostratigraphy.Dowden, Hutchinson, Ross, Inc., Stroudsburg, Penn, pp. 257e281.
Surlyk, F., Boldreel, L.O., Lykke-Andersen, H., Stemmerik, L., 2010b. The Skælskørstructure in eastern Denmark e wrench-related anticline or primary LateCretaceous sea-floor topography? Bulletin of the Geological Society of Denmark58, 99e109.
Surlyk, F., Dons, T., Clausen, C.K., Higham, J., 2003. Upper Cretaceous. In: Evans, D.,Graham, C., Armour, A., Bathurst, P. (Eds.), The Millennium Atlas: PetroleumGeology of the central and northern North Sea. The Geological Society ofLondon), London, pp. 213e233.
Surlyk, F., Damholt, T., Bjerager, M., 2006. Stevns Klint, Denmark: UppermostMaastrichtian chalk, CretaceouseTertiary boundary, and lower Danianbryozoan mound complex. Bulletin of the Geological Society of Denmark 54,1e48.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256252
Surlyk, F., Lykke-Andersen, H., 2007. Contourite drifts, moats and channels in theUpper Cretaceous chalk of the Danish Basin. Sedimentology 54, 405e422.
Surlyk, F., Stemmerik, L., Ahlborn, M., Harlou, R., Lauridsen, B.W., Rasmussen, S.L.,Schovsbo, N., Sheldon, E., Thibault, N., 2010a. The cyclic Rørdal Member e a newlithostratigraphic unit of chronostratigraphic and palaeoclimatic importance inthe upper Maastrichtian of Denmark. Bulletin of the Geological Society ofDenmark 58, 89e98.
Thibault, N., 2010a. Calcareous nannofossils from the boreal Upper Campanian e
Maastrichtian chalk of Denmark. Journal of Nannoplankton Research 31, 39e56.Thibault, N., 2010b. Biometric analysis of the Arkhangelskiella group in the upper
Campanian e Maastrichtian of the Stevns-1 borehole, Denmark: taxonomicimplications and evolutionary trends. Geobios 43, 639e652.
Thibault, N., Schovsbo, N., Harlou, R., Stemmerik, L., Surlyk, F., 2011. An age-calibratedrecord of upper Campanian eMaastrichtian climate change in the Boreal Realm.In: Abstract, 2011 Fall Meeting, AGU, San Francisco, Calif., 5�9 Dec.
Thibault, N., Harlou, R., Schovsbo, N., Schiøler, P., Minoletti, F., Galbrun, B.,Lauridsen, B.W., Sheldon, E., Stemmerik, L., Surlyk, F., 2012a. Upper CampanianeMaastrichtian nannofossil biostratigraphy and high-resolution carbon-isotopestratigraphy of the Danish Basin: towards a standard d13C curve for the BorealRealm. Cretaceous Research 33, 72e90.
Thibault, N., Husson, D., Harlou, R., Gardin, S., Galbrun, B., Huret, E., Minoletti, F.,2012b. Astronomical calibration of upper CampanianeMaastrichtian carbonisotope events and calcareous plankton biostratigraphy in the Indian Ocean(ODP Hole 762C): implication for the age of the CampanianeMaastrichtianboundary. Palaeogeography, Palaeoclimatology, Palaeoecology 337e338, 52e71.
Troelsen, J.C., 1955. Globotruncana contusa in the White Chalk of Denmark. Micro-paleontology 1, 76e82.
Van Adrichem Boogaert, H.A., Kouwe, W.F.P., 1994. Stratigraphic nomenclature:section H e Upper Cretaceous and Danian (Chalk Group). Mededelingen RijksGeologische Dienst 50. Rijks Geologische Dienst (Haarlem).
Van der Molen, A.S., Wong, T.E., 2007. Towards an improved lithostratigraphicsubdivision of the Chalk Group in the Netherlands North Sea area e a seismicstratigraphic approach. Netherlands Journal of Geosciences 86, 131e143.
Varol, O., 1998. Palaeogene. In: Bown, P.R. (Ed.), Calcareous Nannofossil Biostratig-raphy, British Micropalaeontological Society Series. Chapman & Hall/KluwerAcademic, pp. 200e224.
Voigt, S., Gale, A., Jung, C., Jenkyns, H., 2012. Global correlation of Upper Campaniane Maastrichtian successions using carbon isotope stratigraphy: development ofa new Maastrichtian timescale. Newsletters on Stratigraphy 45, 25e53.
Wilson, G.J., 1974. Upper Campanian and Maastrichtian dinoflagellate cysts from theMaastricht region and Denmark. Unpublished Ph.D. Thesis. University of Not-tingham. vþ 601 pp.
Appendix 1
Distribution chart of dinoflagellates, acritarchs and chlorophytes in the Stevns-1well. The occurrence intervals of key species mentioned in the text are shaded. þ isoccurrence outside count. Abbreviations of zones (z), subzones (sz) and zonules (zn)are: Aac¼ Alterbidinium acutulum z, Aco¼ Areoligera coronata z, Ava¼ Alterbidiniumvarium sz, CceTr ¼ Carpatella cornutueTectatodinium rugulatum zn,Cpa ¼ Cladopyxidium paucireticulatum sz, Cut ¼ Cannosphaeropsis utinensis sz,Dga ¼ Deflandrea galeata z, Eha ¼ Eatonicysta hapala sz, Hbo ¼ Hystrichosphaeropsisborisii z, Hco ¼ Hystrichostrogylon coninckii z, Hga ¼ Hystrichokolpoma gamospina z,Ico ¼ Isabelidinium cooksoniae z, Mli ¼ Membranilarnacia liradiscoidesz, Pde ¼ Palaeocystodinium denticulatum z, Pgr ¼ Palynodinium grallator z,Ptu ¼ Pervosphaeridium tubuloaculeatum z, Ico ¼ Isabelidinium cooksoniae z,Sin¼ Senoniasphaera inornata sz, Sma¼ Samlandia mayii z, Tma¼ Tanyosphaeridiummagdalium sz, Tpe ¼ Thalassiphora pelagica sz, Tut ¼ Triblastula utinensis z,Xlu ¼ Xenicodinium lubricum zn.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 253
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256254
Appendix 2
Detailed log of the Stevns-1 core, showing chronostratigraphy, nannofossil anddinoflagellate zonations, lithostratigraphy, sedimentary facies, fossil content, GR rayand d13C logs. As in Fig. 2, biozones have been extended upwards to the base of theoverlying biozone. Correlation of the brachiopod zones (Surlyk, 1984) with the otherzonations is tentative and is based on the combined evidence from the carbon isotopecorrelations between Kronsmoor, Hemmoor and Stevns-1 (Thibault et al., 2012a) and
the brachiopod zonation and correlations between the Rørdal-1 borehole, Hvidskud,Rügen and Hemmoor (Surlyk, 1970) and the zonation of Kronsmoor (Surlyk, 1982).The brachiopod zones are from below: tel ¼ tenuicostataelongicollis, lej ¼ longicollisejasmundi, jea ¼ jasmundieacutirostris, aes ¼ acutirostrisespinosa, ses ¼ spinosaesubtilis, sep ¼ subtilisepulchellus, pep ¼ pulchellusepulchellus, pet¼ pulchellusetenuicostata, tes¼ tenuicostataesemiglobularis, seh¼ semiglobularisehumboldtii, hes ¼ humboldtiiestevensis, sec ¼ stevensisechitoniformis.
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256 255
F. Surlyk et al. / Cretaceous Research 46 (2013) 232e256256
Related Documents
