The Jurassic of the Netherlands

Home , Aerdenhout, Buntsandstein, Germanic Trias, Kimmeridgian, Lias Group, Posidonia Shale

G.F.Waldemar Herngreen, Wim F.P.Kouwe and Theo E.Wong

A recent revision of the lithostratigraphy of the Netherlands has triggered an extensive re-eval- uation of existing ideas on the Jurassic structural and depositional history. Significant advances can be attributed to the incorporation of sequence stratigraphic concepts. In the course of the Triassic and Jurassic, structural complexity increased progressively. The Jurassic sedimentary succession can be subdivided into three depositional megasequences. Megasequence I (Rhaetian– Aalenian) reflects the period between the so-called early and mid-Cimmerian tectonic phases. Megasequence II (Aalenian – Middle Callovian) covers the period of activity of the mid-Cimmerian phase. Megasequence III (Middle Callovian – Ryazanian) corresponds with the period between the mid-Cimmerian and late Cimmerian phases (particularly after pulse II). In this latter megasequence, six stages (IIIa–f) are recognised. Sediments deposited during the Rhaetian and Ryazanian bear a stronger affinity with the Jurassic succession than with Triassic and Cretaceous sediments respectively. These stages are thus treated here as an integral part of the Jurassic succession. During the Rhaetian–Bajocian the area subsided relatively uniformly. A sheet of predominantly fine-grained marine sediments of great lateral uniformity was deposited. During the Toarcian, in particular, basin circulation was largely restricted. The cooling that followed the thermal Central North Sea dome uplift triggered an important extensional phase during the Aalenian–Callovian. The rift phase resulted in the formation of several smaller basins, each with its own characteristic depositional succession. The basins fall into three structural provinces: the eastern province (Lower Saxony Basin, E–W-striking); the northern province (Central Graben, N–S-striking); and the southern–central system (Roer Valley Graben – Broad Fourteens, with a strong NW–SE strike). The mid-Cimmerian event started to affect the Dutch basins during the Bajocian. Sedimentation ceased in the Dutch Central Graben while it persisted in a predominantly coarse-grained, shallow marine facies in the southern basins (Roer Valley Graben, West Netherlands Basin). Extensional tectonics in the Central Graben were initi- ated during the Middle Callovian, with the deposition of continental sediments. During the Oxfordian–Kimmeridgian, marine incursions gradually became more frequent. Marine deposition in the other basins in the south persisted into the Oxfordian, at which time deposition became predominantly continental. Marine conditions gradually returned in the south during the Ryazanian–Barremian, with a series of advancing partial transgressions from the north. The present-day distribution of Jurassic strata in the Netherlands was determined largely by erosion associated with Late Cretaceous – Paleocene uplift.

Keywords: The Netherlands onshore and offshore, Jurassic, lithostratigraphy, sequence stratigraphy, tectonics, regional geology

G.F.W.H.* & T.E.W., Netherlands Institute of Applied Geoscience TNO – National Geological Survey, P.O. Box 80015, NL-3508 TA Utrecht, The Netherlands. *Retired. E-mail: [email protected] W.F.P.K., Wintershall Noordzee B.V., Eisenhowerlaan 146, NL-2517 JL The Hague, The Netherlands.

Geological Survey of Denmark and Greenland Bulletin 1, 217–229 (2003) © GEUS, 2003 217 The Jurassic succession in the Netherlands has signifi- Jurassic and Upper Jurassic – Lower Cretaceous. A cor- cant hydrocarbon source rock and reservoir potential relation of the current Dutch Jurassic – Lower Cretaceous and the stratigraphy of the succession is thus a subject lithostratigraphy with the stratigraphic subdivisions of of particular interest. The Jurassic lithostratigraphic the neighbouring countries is presented in Figure 1. nomenclature in the Netherlands has recently been updated in a joint effort by the Geological Survey of the Netherlands (RGD) and NOGEPA, the organisation of oil companies active in the Netherlands. This pro- Structural setting ject has benefited significantly from integration of new During Triassic–Jurassic times, the structural style of the knowledge on Jurassic biostratigraphy. In addition, Netherlands gradually changed from the single, extensive sequence stratigraphic concepts have been used to Southern Permian Basin into a complex of smaller, largely explain the observed distribution of facies in time and fault-controlled, highs and lows. This transformation, space. The results have been published in part in van related to the break-up of Pangea (Ziegler 1990), took place Adrichem Boogaert & Kouwe (1994–1997). In this study, in several discrete extensional phases: Scythian (Hard- we treat the most recent ideas about the Jurassic geo- egsen), Norian–Rhaetian (early Cimmerian), Aalenian – logical history of the Netherlands. Callovian/Oxfordian (mid-Cimmerian) and Kimmeridgian– The geological history of the Jurassic in the Nether- Valanginian (late Cimmerian). The intervening periods lands has been presented previously by Haanstra (1963), were dominated by regular thermal subsidence. Heybroek (1974) and van Wijhe (1987). Ziegler (1990) The result can be seen by comparing Figures 2 and 3, treated the area from a Northwest European perspec- which display the Triassic and Late Jurassic basin con- tive, whereas Burgers & Mulder (1991) summarised cer- figurations, respectively. In the northern half of the tain aspects of the Late Jurassic and Cretaceous history. Netherlands’ offshore territory, the segregation between Regional stratigraphic overviews of the Jurassic in the highs and basins was enhanced by halokinesis in the southern North Sea have been presented by Brown Permian–Triassic successions along the structural bound- (1990) and Cameron et al. (1992). Michelsen & Wong aries. Associated salt withdrawal commonly determined (1991) presented a stratigraphic correlation between the distribution of Jurassic depocentres. the Dutch, Danish and southern Norwegian sectors of Throughout the Jurassic, the area comprised three the Central Graben. Underhill & Partington (1993) dis- interactive structural provinces (Fig. 3). cussed the effect of Middle Jurassic thermal doming on regional Jurassic stratigraphy in a sequence stratigraphic 1. The Lower Saxony Basin system (previous Ems Low), context. Kimmeridgian to Ryazanian sequence strati- extending into central Germany. graphy, biostratigraphy and the distribution of the main 2. The North Sea Central Graben – Vlieland Basin sys- reservoir intervals in the North Sea were dealt with by tem, trending north–south across the Mid-North Sea Partington et al. (1993). High – Ringkøbing–Fyn High complex. During the last two decades, several authors from the 3. A block-faulted basin system extending NW–SE Geological Survey of the Netherlands (RGD) have pub- through the Netherlands, connecting the Roer Valley lished detailed review papers on the Middle–Late Jurassic Graben, the Central Netherlands Basin, the West history of the Dutch Central (North Sea) Graben, the Netherlands Basin and the Broad Fourteens Basin Vlieland Basin and adjoining onshore areas: Herngreen (previous Off-Holland Low), and linked with the & de Boer (1984), Herngreen & Wong (1989), Herngreen Sole Pit Basin in the UK offshore. et al. (1988, 1991), Wong et al. (1989), Geological Atlas of the Subsurface of the Netherlands, sheets I–V (RGD During the Early Jurassic, the area subsided relatively 1991a, b, 1993a, b, 1995) and X (NITG–TNO 1998; map uniformly. A sheet of open marine, fine-grained sedi- sheet VI is in press and sheets VII and VIII are currently ments of great lateral uniformity was deposited. Structural in preparation). complexity gradually increased during Early and Middle The accumulated RGD knowledge, combined with Jurassic times, and reached a maximum in the Callovian. contributions by several oil companies, served as a During the Middle and Late Jurassic, in particular, each basis for the revision of the existing lithostratigraphic of the above-mentioned provinces accumulated its own nomenclature for the Netherlands (van Adrichem characteristic depositional succession. Boogaert & Kouwe 1994–1997). The revision of the The impact of the uplift of the Central North Sea Jurassic involved two working groups: Permian – Middle thermal dome during the Aalenian–Bathonian is most

218 Sandstein Rothenberg- (Hilston Fm) Germany Macrocephalenton Minumuston Rhätkeuper Neokom-Schieferton (western part) Münder Fm Gigasschichten Lower Saxony Basin Heersumer Schichten Eimbeckhäuser Plattenkalk Bückeberg Fm (‘Wealden’) Serpulit Mb Ornatenton Bentheimer Sandstein Kimmeridgekalke & -mergel Sandstein Gildehäuser

984)

Dogger eprLias Keuper 1 Malm 959), 1 975), 1 ( oolith Korallen- et al. Osning grønsand Fm 976), Klassen ( Flammenmergel 1 Vlieland Sandstone Casey Fm quarzit

Sleen Fm equals Kimmeridgian

source: Brinkmann ( Weiteveen Fm Coevorden Fm Aalburg Fm Osningsandstein Vlieland

Wiehengeb.- Claystone Werkendam Fm

Holland Fm Kemper( Netherlands ‘Cornbrash’ Aspidoides- Sandstein Württembergicus- Sandstein Posidonia Shale Fm Posidonienschiefer Porta-Sandstein (Macroceph. sst)

Niedersachsen Gp Niedersachsen Rijnland Group Rijnland (north-)eastern sector sensu lato Fm Fm Poul Fm Vyl Heno

Bryne Fm Altena Group Altena ) ountries. Kimmeridgian ? Sola Fm 986), 1 1991 Rødby Fm Tuxen Fm Lola Fm ( Fjerritslev Fm Winterton Fm Valhall Fm Fm Sand et al. Lower Graben Shale Fm Farsund Fm Middle Graben Denmark

Michelsen & Wong (

source: Jensen

Cromer Knoll Group Knoll Cromer Central Graben Gp Graben Central

Danish Central Graben

Subgroup Rijnland Group Rijnland Scruff Group Scruff Central Graben Central Fm Upper Graben Lower Graben Fm (2003, this volume). Modified from van Adrichem Boogaert & Kouwe (1994–1997). Middle Graben Fm Fm Hole Puzzle et al. Clay Fm Scruff Kimmeridge Sleen Fm Fm Aalburg Fm Front Holland Fm Friese Vlieland Claystone Fm Greensand Fm

Netherlands

Posidonia Shale Fm Zurich Fm Zurich

Werkendam Fm Fm Fm Breeveertien

Vlieland Sandstone Fm Nieuwerkerk

Brabant Fm central and western sectors composite for the northern,

Delfland Subgroup Delfland

Schieland Group Schieland Altena Group Altena 992) 74), 1 19 ( = hiatus et al. ? United Kingdom Southern North Sea

source: Rhys (

Cameron

Group Cromer Knoll Group Knoll Cromer Group Humber Group Sole West Lias Group Lias Penarth ) . For recent revisions of the Danish scheme, see Michelsen Age Albian Aptian Bajocian Aalenian Rhaetian Toarcian Callovian sensu lato Ryazanian Bathonian Oxfordian Barremian Hettangian ( Valanginian Sinemurian Portlandian

Hauterivian

Pliensbachian Kimmeridgian

Epoch Cretaceous Early Jurassic Middle Late Jurassic Late Early Jurassic Early Triassic L. sensu anglico Fig. 1. Regional lithostratigraphic correlation chart of the Jurassic – Lower Cretaceous for Netherlands and neighbouring c

219 Winterton Fm Red Chalk Fm Oxford Clay Fm Speeton Clay Fm Kimmeridge Clay Fm Fm Corallian Fm Spilsby Sandstone A Ringkøbing–Fyn A Mid North Mid North Sea Outer High Ringkøbing–Fyn Sea High High Rough Basin High Elbow Spit High B B Elbow Spit

High E F E F 100 km

Step Graben 100 km G G Central Graben Schill Grund High Cleaver Bank Rifgronden fault zone

Central Graben High 54°N 54°N K 1 2 3 LMN K L M N Terschelling Basin Ameland 4 5 6 Block 7 8 9 Vlieland 10 11 12 Sole Pit High Hantum fault zoneLauwerszee Groningen Sole Pit Basin Trough High Basin 13 14 15 Indefatigable fault zone Vlieland Broad Basin 16 17 18 Netherlands Fourteens Texel–IJsselmeer Swell Basin Noord–Holland Friesland P Q Q P Platform High Platform Off-Holland IJmuiden Lower Saxony Low Winterton High Basin High Gouwzee South Trough Hewett Ems Low Zandvoort Ridge Shelf Central Netherlands Gronau fault zone West Netherlands Basin West Netherlands O Basin East Netherlands O 52°N 52 N Basin R S High ° R S Maas- bommel High

Roer Valley Roer Valley Graben Peel Block Krefeld High Graben

London–Brabant Rhenish London–Brabant Massif Massif Massif Rhenish Massif 3°E 5°E 7°E 3°E5°E7°E

Structural high/subaerial landmass Fig. 3. Middle–Late Jurassic to Early Cretaceous structural elements in the Netherlands. For legend, see Fig. 2. Modified from van N Platform/occasionally flooded Adrichem Boogaert & Kouwe (1994–1997). UK DK G Basin NL Major normal fault (zone)

Seismic line shown in Fig. 6 regime triggered Callovian–Kimmeridgian rifting, result- Fig. 2. Main Triassic to Early Jurassic structural elements in the ing in the formation of the North Sea Central Graben Netherlands. The K-quadrant shows the block numbering system rift system. used for the Netherlands’ continental shelf. Each complete quad- The uplift phase terminated the uniform subsidence rant (1°N x 1°E) is divided into 18 blocks measuring 10´N x 20´E, and sheet-like deposition that characterised the Early numbered from NW to SE. Incomplete quadrants are numbered and Middle Jurassic. Rifting induced structural differ- as if they were complete (e.g. the O-quadrant only comprises entiation into rapidly subsiding basins with high sedi- blocks 12, 15, 17 and 18). National sectors of the North Sea: DK, Denmark; G, Germany; N, Norway; NL, the Netherlands; UK, ment infill rates and more stable, sediment-starved, United Kingdom. Modified from van Adrichem Boogaert & Kouwe platform areas. This differentiation persisted until the (1994–1997). Early Cretaceous. Outside the main basins depicted in Figure 3, Upper Jurassic deposits are rare and thin, and associated with salt domes (rim synclines) or transverse evident in the northern offshore area of the Netherlands, fault zones. where Lower Jurassic successions are deeply truncated. The north-eastern part of the Netherlands formed the The combination of initial cooling of the thinned crust western fringe of the German Ems Low – Lower Saxony under the dome and an overall transtensional tectonic Basin system. The Ems Low, a north–south elongated,

220 fault-bounded basin during Carboniferous–Triassic times, With the available data and time, the construction of evolved into the slightly east–west-trending, sag-like a specific, local sequence framework fell outside the Lower Saxony Basin during the Middle Jurassic. A rel- scope of the working group. Instead, the group tied the atively undisturbed, continuous Jurassic succession is recognised transgressive and regressive events to the found in the central parts of the basin in Germany (Fig. best-fitting sequences in the cycle chart published by 1). In the eastern Netherlands’ development, a hiatus Haq et al. (1988). This Haq et al. (1988) time-scale has spanning the Aalenian – Early Kimmeridgian reflects the been recalibrated numerically to the scale of Harland situation along the western margin of the basin. et al. (1990), which was chosen as the current standard The West Netherlands Basin, the Roer Valley Graben for Dutch stratigraphy. For the sake of completeness, and the Broad Fourteens Basin formed a different depo- Figures 4 and 5 (facing pages 226 and 227, respectively) sitional province, connected with the Sole Pit Basin of indicate the Haq et al. (1988) sequence subdivision for the UK sector of the North Sea. Since Permian–Triassic the whole of the Jurassic; Figure 5 provides an overview salts are largely absent in the subsurface here, these of some significant biostratigraphic marker horizons basins demonstrate a pure block-faulted nature. The that were used for calibration of Dutch lithostratigraphy three mentioned provinces merge in the onshore with the cycle chart. Sequence stratigraphic analysis Netherlands, where the Central Netherlands Basin and was carried out using concepts defined by the Exxon the Vlieland Basin (a small pull-apart basin) were posi- school, viz. sequences are stratal units bounded by tioned. The transitions between these provinces are unconformities and their correlative conformities (Van now obscured as a result of later erosion which has Wagoner et al. 1988). In contrast, concepts of genetic stripped Jurassic sediments from most of the country. sequence stratigraphy (sensu Galloway 1989), in which genetic sequences are bounded by maximum flooding surfaces, are commonly invoked for regional correlation studies. An example of this approach is found in Application of sequence stratigraphy Partington et al. (1993), for their regional correlation of In connection with the revision of the existing litho- the Jurassic of the North Sea area. It should be noted stratigraphic nomenclature for the Netherlands (van that their interpretation of Dutch Jurassic sediments was Adrichem Boogaert & Kouwe 1994–1997), sequence based on obsolete ideas derived from NAM & RGD stratigraphic analysis was seen as a valuable additional (1980). Figure 4 presents the most modern ideas on the tool for a better understanding of the complex geo- Dutch chrono-lithostratigraphic development in the logical settings and stratigraphic relationships. The context of the development in the surrounding coun- Lower and Middle Jurassic successions in the Netherlands tries. are of open marine origin, and developed in region- ally uniform facies. Depositional cycles are commonly discerned in this interval, and some of these were already incorporated in the old lithostratigraphic sub- Depositional history division by NAM & RGD (1980). In the recent revisions, The Jurassic succession of the Netherlands can be sub- therefore, it was not considered necessary to improve divided into three depositional megasequences. Mega- this scheme by incorporation of results from new bio- sequence I (Rhaetian–Aalenian) reflects the period stratigraphic or sequence stratigraphic analyses. In the between the early and the mid-Cimmerian tectonic (Middle–)Upper Jurassic, however, the common inter- phases. Megasequence II (Aalenian – Middle Callovian) calation of continental and marine deposits makes covers the period of activity of the mid-Cimmerian sequence stratigraphy especially effective. Therefore phase. Megasequence III (Middle Callovian – Ryazanian) all available data (well and seismic correlations, bio- corresponds to the period between the mid-Cimmerian stratigraphic and palynological data) were integrated into and the late Cimmerian (pulse II) phases (RGD 1991a). a regional sequence stratigraphic framework. This framework was used to select those units which were suit- able candidates for lithostratigraphic units. Criteria for unit selection included mappability, relevance for explo- Rhaetian–Aalenian (Megasequence I) ration geology and the existence of diagnostic lithological This period was characterised by the deposition of a and/or biostratigraphical criteria for their recognition. very uniform blanket of marine shales across large parts of Northwest Europe. In the Netherlands, these deposits

221 are placed in the Altena Group. After a long period of The impact of the mid-Aalenian Central North Sea restricted marine to continental deposition in the Triassic, uplift is negligible in the southern basins (Broad the last pulse of the early Cimmerian extensional phase Fourteens Basin, West Netherlands Basin, Roer Valley in the earliest Rhaetian caused a marine transgression Graben). Werkendam Formation deposition continued, across large parts of Europe. Very fine-grained deposits with an important Bajocian influx of marine sandstones of Rhaetian age, containing abundant lacustrine and along the southern basin margin. Depositional facies marine fossils, are placed in the Sleen Formation. changed to shallow marine, sandy carbonates and marls Hettangian–Pliensbachian or lowermost Toarcian sed- during the Bathonian (Brabant Formation, ‘Cornbrash iments, consisting of a uniform succession of dark grey facies’). At least three carbonate–marl cycles were or black silty claystones with abundant pyritised fossil deposited in the Bathonian to Oxfordian, which are at remains, are called the Aalburg Formation. Towards present only preserved as erosional remnants in the the London–Brabant Massif (the southern basin fringe southern basins. during the Early Jurassic), an increasing number of thin In the Dutch Achterhoek (eastern onshore), on the limestone beds are intercalated in this unit. south-western fringe of the Lower Saxony Basin, a spe- Basin circulation became restricted during the cial development is found (Herngreen et al. 1984). The Toarcian, with anoxic bottom waters and deposition of sedimentary succession up to the Middle Bathonian a bituminous shaly claystone, called the Posidonia shows strong parallels with successions of the Roer Formation, over large parts of Northwest Europe. It Valley Graben and the German Lower Saxony Basin constitutes the most prominent oil source rock in the proper (Fig. 1). The whole area appears to have been Netherlands. Basin circulation returned to normal dur- a single depositional province during this period. At the ing the Late Toarcian – Bajocian, as indicated by the transition to the Late Bathonian, however, a differenti- deposition of the Werkendam Formation, consisting of ation occurred. During the Late Bathonian – Callovian, marine silty mudstones and greensands. an open marine claystone facies was deposited in Germany and the Achterhoek (informally termed the Klomps member, Fig. 4). In contrast, deposition of shallow marine sandy carbonates and marls in the Roer Aalenian – Middle Callovian (Megasequence II) Valley Graben and the West Netherlands Basin per- This was a period of significant tectonic activity, which sisted into the Oxfordian. caused important structural differentiation (Figs 2, 3). The main effect of the tectonic phase traditionally addressed in the Netherlands as ‘mid-Cimmerian’ was the uplift of the Central North Sea dome. The defor- Middle Callovian – Ryazanian mation front gradually shifted southwards with time, (Megasequence III) resulting in a considerable delay between the timing of Upper Jurassic – Lower Cretaceous deposits in Northwest deformation of the dome crest in the Central North Sea Europe demonstrate a step-by-step overall transgression (mid-Aalenian) and the southernmost Dutch provinces from north to south. Periods of marine transgression alter- (Kimmeridgian). The amount of intra-Jurassic truncation nated with phases of short-term progradation of, partly decreases away from the dome (Underhill & Partington tectonically controlled, continental siliciclastics. The 1993), and consequently is most severe within the area continuous shifting of marine and terrestrial realms in of this study in the Dutch Central Graben, the northern- response to syndepositional tectonism and sea-level most province of the Netherlands, where open marine fluctuations is reflected by the recurrent intertonguing deposition of the Altena Group ceased in the Bajocian. of marine and continental sediments. The predomi- The Dutch part of the Central Graben remained non- nantly marine Scruff Group (Upper Jurassic – Ryazanian) depositional during the Bathonian – Early Callovian. In and Rijnland Group (Lower Cretaceous) interfinger with the Middle Callovian, deposition gradually resumed, in the mainly continental Schieland Group (Upper Jurassic a continental facies. The uplift event probably also – Barremian) and the paralic to restricted marine affected the Terschelling Basin, the Dutch Lower Saxony Niedersachsen Group (Upper Jurassic – Ryazanian). Basin and the Central Netherlands Basin. However, the Differential movement of fault blocks was caused by a evidence for the impact of this phase was removed by combination of oblique-slip effects in an overall exten- later, more severe truncation in the Jurassic successions sional regime and halokinesis in areas with salts in the of these basins. subsurface (Wong et al. 1989). Together with a high sed-

222 iment input, this resulted in complex sediment distrib- the end of the Oxfordian (sequence LZA-4.4 of Haq et ution patterns and continuously shifting depocentres. al. 1988). By this time, Kimmeridge Clay deposition The cyclic alternation of marine and continental sedi- also invaded the Step Graben, onlapping the Upper ments indicates that sediment deposition was also Permian Zechstein Group. strongly controlled by sea-level changes. Non-marine deposition of the Schieland Group had already commenced in the Dutch Central Graben during the Callovian, but deposition of the marine Brabant Formation (Altena Group, Oisterwijk Limestone Mem- Middle Callovian – Oxfordian (Stage IIIa) ber) persisted into the Early–Middle Oxfordian in the In the Middle–Late Callovian, predominantly continen- southern Netherlands (Haanstra 1963; NAM & RGD tal sedimentation (Schieland Group) resumed along the 1980). Cessation of marine Altena Group deposition in axis of the northern Dutch Central Graben (Fig. 4). The the Roer Valley Graben, the West Netherlands Basin, the basal alluvial plain deposits are referred to the Lower Broad Fourteens Basin and probably the Central Graben Formation. This unit displays huge thickness vari- Netherlands Basin – Lower Saxony Basin during the ations due to onlap onto syndepositional topography, Late Oxfordian – earliest Kimmeridgian was triggered and due to differential subsidence. The depositional by tectonic pulse I of the late Cimmerian. In the Roer area gradually extended into the southern Dutch Central Valley Graben and the West Netherlands Basin, the Graben in the course of the latest Callovian, Oxfordian Brabant Formation is locally overlain unconformably by and Kimmeridgian. Deposition in the latest Callovian erosional remnants of Late Oxfordian – Portlandian started with the marginal marine Rifgronden Member deposits in continental floodplain facies (Schieland of the Friese Front Formation. It indicates connections Group, Nieuwerkerk Formation). to open marine areas in the northern Central Graben (Central North Sea), or possible links with the marine realm in the southern and central Dutch basins. The shift to deposition of the Middle Graben Early–Late Kimmeridgian (Stage IIIb) Formation in the latest Callovian – Early Oxfordian During the Kimmeridgian and Portlandian, the northern reflects an abrupt change to more fine-grained, lake- Dutch Central Graben became a major depocentre, and swamp-dominated sedimentation. This shift was accumulating a thick succession of increasingly marine accompanied by a short-lived, marine incursion into sediments. The area of deposition once more expanded the whole Dutch Central Graben, which is correlated significantly. Deposition resumed in continental facies with the maximum flooding surface of sequence LZA- in the Broad Fourteens Basin, the Dutch Lower Saxony 4.1 of Haq et al. (1988). During the Middle Oxfordian, Basin and the Vlieland Basin (Fig. 4). The depositional lacustrine conditions prevailed throughout the Dutch style in the Broad Fourteens and Vlieland Basins Central Graben. Marine incursions were scarce and remained continental (floodplain, lacustrine, with occa- restricted to the far north during the rest of the Oxfordian. sional sandy fluvial intercalations), with a few marine The Oxfordian was a period of significant trans- incursions. The Vlieland Basin was the site of volcanic gression and onlap. Areas adjacent to the northern activity in the Middle–Late Jurassic, as the Zuidwal vol- Dutch Central Graben, such as the southern Dutch canic dome formed (Perrot & van der Poel 1987; Central Graben, Terschelling Basin and Step Graben Herngreen et al. 1991). Depending on the time-scale were incorporated into the depositional area. Simul- used, volcanic activity (dated radiometrically at 155–143 taneously, the open marine realm started to expand Ma) may have taken place somewhere between the southwards into the Dutch Central Graben, first into Callovian and the Early Ryazanian. block F03 (Middle–Late Oxfordian, sequence LZA-4.2 In the course of the Kimmeridgian, deposition of the of Haq et al. 1988). Initially, a stacked prograding paralic Puzzle Hole Formation in the central Dutch coastal-barrier sand complex (Upper Graben Formation) Central Graben gradually gave way to the open marine developed, behind which a paralic delta plain formed, Kimmeridge Clay Formation in the area of blocks represented by the deposits of the Puzzle Hole Formation F08–F11. Thin marine sand bodies are found locally in (blocks F08–F14). North of the barrier complex, the the uppermost parts of the Puzzle Hole Formation, sug- Kimmeridge Clay Formation represents the open marine gesting the existence of a backstepping coastal-barrier environment. The coastal sand bodies of the Upper system. However, much of the character of the trans- Graben Formation in the area of block F03 drowned at gression cannot be reconstructed due to Subhercynian

223 and/or Laramide erosion (Late Cretaceous – Paleocene). mation, Fig. 4). Two distinct transgressive phases are To the south (blocks F15–F17), the paralic Puzzle Hole identified; in the early Late Kimmeridgian, the trans- Formation grades into deposits characterised by conti- gression reached block F18, while block L02 became nental alluvial plain facies (Delfland Formation of transgressed by the latest Kimmeridgian. These events Herngreen & Wong, 1989; now called Friese Front are tentatively correlated with the transgressive systems Formation). In the southern Dutch Central Graben, allu- tracts of sequences LZA-4.7 and LZB-1.1 of Haq et al. vial plain deposition replaced the predominantly lacus- (1988). The latter flooding event is associated with trine deposition around the end of the Oxfordian. During onlap onto exposed Triassic and Permian rocks in the the Early Kimmeridgian (LZA-4.4 of Haq et al. 1988), Terschelling Basin (Oyster Ground Member in block the depositional area in the southern Dutch Central F15) and the Vlieland Basin – Central Netherlands Basin Graben expanded. Seismic and palaeogeographic infor- area (continental Zurich Formation). At the same time, mation suggest that the boundaries between the areas tectonic tilting and associated halokinesis caused the of deposition of the Puzzle Hole Formation, the depocentre of the Dutch Central Graben to shift from Kimmeridge Clay Formation and the Friese Front the central–eastern axis (from block F03, extending Formation were determined by faults. southwards into blocks L03–F18) to the western graben In the Broad Fourteens Basin, widespread deposi- margin (block F02–L05). The seismic cross-section of tion commenced in the Early Kimmeridgian (LZA-4.5 the graben system shows this westwards shift (Fig. 6). of Haq et al. 1988), with the accumulation of sandy During the Late Kimmeridgian – Portlandian, silici- alluvial plain sediments referred to the Aerdenhout clastic deposition in the Lower Saxony Basin was peri- Member of the Breeveertien Formation (Fig. 4). This odically replaced by accumulation of evaporites and member unconformably overlies deposits of the Altena carbonates (evaporitic and marl members of the Group or the Upper Germanic Triassic. The progres- Weiteveen Formation, Fig. 4). These cycles may be cor- sive transgression observed in the Central Graben coin- relatable with the alternation of coarser clastics and cides with a shift from alluvial plain (Aerdenhout fines with minor evaporites found in the Broad Fourteens Member) to lacustrine and lagoonal deposition Basin (Breeveertien Formation, several members). The (Fourteens Claystone Member) in the Broad Fourteens lithofacies (carbonates, marls, evaporites, coals) of the Basin (associated with the maximum flooding surface Zurich Formation in the remnants of the Central of sequence LZA-4.6 of Haq et al. (1988). Deposition Netherlands Basin (‘Voorthuizen subbasin’ of Haanstra of the Basal Weiteveen Clastic Member in the Dutch 1963; Gouwzee Trough of RGD 1993a) are similar to Lower Saxony Basin (= Niedersachsen Basin) seems to those in the Niedersachsen Group in the Dutch Lower have started close to the end of the Early Kimmeridgian. Saxony Basin. The introduction of coarser siliciclastics in the Dutch In the West Netherlands Basin and the Roer Valley Central Graben (main Friese Front member, Puzzle Hole Graben, lacustrine and alluvial plain deposition was Formation and Upper Graben Formation), the Broad restricted to those fault blocks undergoing strongest Fourteens Basin (Breeveertien Formation, Aerdenhout subsidence. A progressive depositional onlap is seen Member) and the Dutch Lower Saxony Basin (Weiteveen in the Portlandian–Ryazanian section. In each consec- Basal Clastics Member) coincided with the start of the utive depositional sequence, higher basin-fringe fault late Cimmerian phase (Haanstra 1963; ’t Hart 1969; ‘Late blocks became part of the depositional area. Very thick Kimmerian I pulse’ of RGD 1991b). The resulting uplift successions of proximal alluvial plain deposits can be terminated the first depositional phase of the Nieuwer- found in places. kerk Formation in the most rapidly subsiding areas of In the Portlandian and Ryazanian, deposition resumed the Roer Valley Graben and the West Netherlands Basin. in the Central Netherlands Basin. The depositional style is transitional between the mainly lacustrine and evaporitic facies of the Lower Saxony Basin and the paralic and restricted marine facies of the Central Graben – Vlie- Late Kimmeridgian – earliest Portlandian (Stage IIIc) land Basin. Deposition in the southern province (West In the Late Kimmeridgian, the ongoing transgression led Netherlands Basin and the western Roer Valley Graben) to the first marine influence on sedimentation in the ceased due to uplift in the Kimmeridgian (around the southern Dutch Central Graben and the Terschelling lower sequence boundary of LZB-1.1 of Haq et al. 1988). Basin. This is witnessed by the deposition of the marine- Non-deposition lasted until the latest Portlandian – influenced Oyster Ground Member (Friese Front For- Ryazanian. From then on, continental sediments were

224 deposited; marine conditions did not reach this area until Basin and Central Netherlands Basin, which had thus the Late Hauterivian – Barremian. far remained exposed, became inundated by the sea. In the latter basin, the depositional area expanded to the north-west. In the Broad Fourteens Basin, this overall regressive Portlandian (Stage IIId) tendency is reflected by the transition within the During the Early Portlandian, the ongoing transgres- Breeveertien Formation from lacustrine and lagoonal sion resulted in deposition of the Terschelling Member coastal plain fines (Fourteens Claystone Member and of the Friese Front Formation, reflecting coastal depo- Driehuis Mottled Claystone Member) to widespread sition along the southern fringe of the Dutch Central sandy alluvial plain deposits (Bloemendaal Member). Graben (blocks L09–L12, sequences LZB-1.2, -1.3 of In the Dutch Lower Saxony Basin, the Late Portlandian Haq et al. 1988). To the north, the Friese Front Formation shoaling trend is demonstrated by the Serpulite Member grades into the open marine Scruff Greensand Formation of the Weiteveen Formation. This widespread carbon- in the southern Dutch Central Graben. Thick, sand-dom- ate deposit marks the culmination of clastic starvation inated successions of Portlandian–Ryazanian age were in this area. deposited here (blocks F15–F18, sequences LZB-1.3 to Deposition of evaporites and carbonates with sub- -1.5 of Haq et al. 1988). Equivalent, thinner sand tongues ordinate siliciclastics (Weiteveen Formation) in the Lower are found in the eastern Terschelling Basin, the Vlieland Saxony Basin was replaced by open water lacustrine Basin and the northern Dutch Central Graben (blocks deposition (Coevorden Formation) at the beginning of F03–F05). During this period, the Vlieland Basin became the Ryazanian. This event is interpreted as indicative divided into two subbasins, separated by the Zuidwal of a flooding phase that correlated with the transition volcanic dome (Herngreen et al. 1991). During the Early from the sandy fluvial Bloemendaal Member to the Portlandian, marine conditions only prevailed in the lagoonal Neomiodon Claystone Member (both of the northern subbasin. The southern subbasin was char- Breeveertien Formation) in the Broad Fourteens Basin. acterised by continental (lacustrine to lagoonal) depo- This period was also marked by widespread deposition sition. of sediments referred to the Nieuwerkerk Formation in The Scruff Greensand Formation grades into the the Roer Valley Graben and West Netherlands Basin; Kimmeridge Clay Formation in the northern Dutch thick successions of locally coarse alluvial plain sedi- Central Graben. The depocentre of the open marine ments were deposited on rapidly subsiding fault blocks Kimmeridge Clay Formation, which prior to the along the axes of the basins. The depositional area con- Portlandian was situated in this northern area, abruptly tinued to expand gradually. The basin margins were shifted to the southernmost Central Graben and the either covered by a thin, condensed succession (e.g. northern Vlieland Basin. In the southern B-quadrant, locally in the province of Groningen), or remained basin circulation stagnated during the Portlandian. This exposed and non-depositional. resulted in deposition of the bituminous claystones of the Clay Deep Member. Euxinic marine conditions became more widespread in the northern Dutch Central Graben during the Ryazanian (sequence LZB-1.5 and Late Ryazanian (Stage IIIf) particularly LZB-1.6 of Haq et al. 1988). During the Ryazanian (sequence LZB-1.6 of Haq et al. 1988), the stagnant marine basin area in the northern Dutch Central Graben expanded southwards into block F05. Deposition of the Clay Deep Member completely Late Portlandian – Ryazanian (Stage IIIe) superseded Scruff Greensand Formation deposition During the Late Portlandian (sequence LZB-1.5 of Haq around the mid-Ryazanian. This change in depositional et al. 1988), marine conditions (Scruff Greensand For- style coincided with the first signs of tectonic pulse II mation) briefly reached the entire Vlieland Basin. In of the late Cimmerian (RGD 1991a). This also caused the southern Dutch Central Graben, the marine basin local truncation of the Scruff Greensand Formation and became shallower, inducing the northwards prograda- the Friese Front Formation in the southern Central tion of shallow marine, spiculitic greensands (Scruff Graben (parts of blocks L02–05). Initially, sedimenta- Spiculite Member). Even the more elevated areas (for tion of the Scruff Greensand Formation resumed briefly example over salt domes) of the Dutch Lower Saxony (Stortemelk Member, correlated with the lowstand of

225 sequence LZB-1.6 of Haq et al. 1988). Subsequently, the deep marine basin expanded markedly southwards, Petroleum geology depositing Kimmeridge Clay Formation sediments (Schill Several Jurassic formations have economic significance Grund Member) in the previously shallow marine to con- in the Netherlands, either as reservoirs or as oil source tinental realm. This marine incursion also reached the rocks. Figures 1 and 4 show the stratigraphic positions Vlieland Basin, where the Stortemelk Member is found of the units mentioned in this context below, and their intercalated with lagoonal–lacustrine deposits of the equivalents in neighbouring countries. The Toarcian Zurich Formation. In the Broad Fourteens Basin, tec- Posidonia Formation is the most prominent oil and wet tonic pulse II of the late Cimmerian is expressed as two gas source rock in the Dutch subsurface (Bodenhausen minor unconformities (base and intra-Neomiodon & Ott 1981), to which the majority of the oil reserves Claystone Member, Breeveertien Formation). in the country can be attributed. Additional oil sourc- In the Dutch Central Graben, large-scale differen- ing potential can be attributed to certain lacustrine strata tial subsidence ended with tectonic pulse II of the late of the Coevorden Formation (Ryazanian) in the Lower Cimmerian (mid-Ryazanian and earliest Valanginian). Saxony Basin. This interval is also known to act as an From then on (sequence LZB-2.1 of Haq et al. 1988), oil source rock in adjacent parts of Germany. The highly a more uniform sedimentation pattern started, associ- bituminous Clay Deep Member (Ryazanian) of the ated with the post-rift thermal sag phase. This is illus- Kimmeridge Clay Formation in the northern sector of trated by the contrast between the highly variable the Dutch Central Graben has oil-sourcing potential. thickness of the succession underlying the Stortemelk However, the areal distribution and stratigraphic range Member and the more uniform development of the of this deposit is much smaller than that of equivalent post-uplift succession (Clay Deep Member, Stortemelk bituminous intervals in the Kimmeridge Clay Formation Member and Schill Grund Member). In the Broad (and equivalents) in the UK, Danish and Norwegian off- Fourteens Basin, the West Netherlands Basin and the shore, where it constitutes one of the major oil source Roer Valley Graben, the highly differential subsidence rocks. patterns continued at least throughout the Valanginian. Coal occurrences in the Lower Graben Formation (Middle–Upper Callovian), the Middle Graben Formation (Oxfordian), the Puzzle Hole Formation (mainly Kimmeridgian) and the Friese Front Formation (upper- Subsequent history most Callovian – Portlandian) may locally have sourced The expansion of the marine sedimentation area con- wet gas. However, in most areas, burial was insuffi- tinued during the Cretaceous, until eventually the cient to reach the gas window (Wong et al. 1989). On London–Brabant Massif became flooded in the the other hand, gas source rocks of Late Carboniferous Campanian–Maastrichtian. The Jurassic successions in age are more or less ubiquitous throughout the the Dutch subsurface were deformed by several later Netherlands. The main problem for gas generated from tectonic phases. The Santonian–Campanian (Subher- these older rocks is to pass through the cover of Permian cynian) and Early Paleogene (Laramide) inversion phases salts and reach the Jurassic. Furthermore, the maximum had the most severe impact. During these compressive burial depths of the Carboniferous strata, for instance events, the Jurassic depocentres were inverted (van in the Central Graben, may have caused these rocks to Wijhe 1987). Practically all Jurassic sediments were become overmature. removed along the inversion axes of these basins. At At present, oil and gas reserves have been discov- present, the occurrences of Jurassic rocks are restricted ered in the Lower Graben Formation (Middle–Upper to the basinal areas (Fig. 3). Subsequent Tertiary sub- Callovian), Upper Graben Formation (uppermost sidence in the Netherlands was more or less evenly Oxfordian), Scruff Greensand Formation (Portlandian) distributed. Subsidence rates were highest in the nor- and Friese Front Formation (uppermost Callovian – thern Dutch offshore, however, and Tertiary (particu- Portlandian) in the Central Graben area. Some sandstone larly Neogene) sediment distribution patterns are domi- members of the Breeveertien Formation (Kimmeridgian– nated by large-scale progradation in this direction. Ryazanian) in the Broad Fourteens Basin were found to be oil-bearing. In the West Netherlands Basin, the Ryazanian and younger levels of the Nieuwerkerk Formation are prospective. The Middle Werkendam Member (Bajocian) and carbonate members of the

226 ENE Puzzle Hole Fm ENE Base Lower Germanic Trias Group (base Buntsandstein Formation) Intra-Triassic level II (Muschelkalk Evaporite Member) Intra-Triassic level III (near-base Middle Buntsandstein Subgroup) Euxinic restricted marine claystones (Clay Deep Mb (Kimmeridge Clay Fm), Posidonia Shale Fm) Open marine claystone (Vlieland Claystone Formation) Open marine & lagoonal claystone (Kimmeridge Clay Formation, Altena Group) Open marine argillaceous sandstone/greensand (Scruff Greensand Formation) Shallow marine/coastal sandstone (Upper Graben Formation) Coal-rich coastal plain (Puzzle Hole Formation) Fine-grained fluvial plain, overbank dominated (Middle Graben Formation) Sandy fluvial plain, channel dominated (Lower Graben Formation) F09-01 Salt Fm Zechstein taceous section has been colour-coded accordingtaceous section has been colour-coded Depositional setting/seismic facies Altena Gp F08-02 Lower Graben Fm Middle Graben Fm Posidonia Shale Fm Puzzle Hole Fm. Upper Graben Fm F11-03 Intra-Triassic level I (near-base Keuper Formation) Base North Sea Groups Base Chalk Group Base Valanginian Base Scruff Greensand Formation Base Kimmeridge Clay Formation; Oyster Ground Mb Base Upper Graben Formation Base Middle Graben Formation Base Lower Graben Formation Base Puzzle Hole Formation, Friese Front Formation Base/top Posidonia Shale Formation Base Altena Group (base Sleen Formation) Kimmeridge Clay Fm WSW Reflectors Fig. 6. Seismic cross-section, running WSW–ENE across the Dutch sector of Central Graben (Fig. 2). The Jurassic – Lower Cre to the main depositional facies.

1.0 2.0 3.0 TWT sec TWT

227 Clay Deep Mb. Lower North Sea Gp Upper Germanic Trias Gp Scruff Greensand Fm. Salt Fm Zechstein Rijnland Gp Lower Germanic Trias Gp Chalk Gp Brabant Formation (Callovian–Oxfordian) have locally Casey, R., Allen, P., Dörhöfer, G., Gramann, F., Hughes, N.F., been shown to be oil-bearing in the Roer Valley Graben Kemper, E., Rawson, P.F. & Surlyk, F. 1975: Stratigraphic sub- and the West Netherlands Basin. division of the Jurassic–Cretaceous boundary beds in NW Exploration of the Jurassic in the Netherlands has Germany. Newsletter on Stratigraphy 4, 4–5. reached a mature stage. The acquisition of high-qual- Galloway, W.E. 1989: Genetic stratigraphic sequences in basin ity seismic and well data and the good biostratigraphic analysis I: architecture and genesis of flooding-surface bounded control obtained in recent years have resulted in a clear depositional units. American Association of Petroleum Geologists Bulletin 73, 125–142. regional geological picture. These data also allow, for Haanstra, U. 1963: A review of Mesozoic geological history in the the first time, the application of sequence stratigraphy. Netherlands. Geologie en Mijnbouw 21, 35–57. Integration of sequence stratigraphic concepts into the Haq, B.U., Hardenbol, J. & Vail, P.R. 1988: Mesozoic and Cenozoic revision of Dutch lithostratigraphy (van Adrichem chronostratigraphy and cycles of sea-level change. In: Wilgus, Boogaert & Kouwe 1994–1997) has resulted, in partic- C.K. et al. (eds): Sea-level changes – an integrated approach. ular, in a far better understanding of the Upper Jurassic Society of Economic Paleontologists and Mineralogists Special stratigraphy of the Netherlands. Publication 42, 71–108. Harland, W.B., Armstrong, R.L., Cox, A.V., Craig, L.E., Smith, A.G. & Smith, D.G. 1990: A geologic time scale 1989, 263 pp. Cambridge: Cambridge University Press. Acknowledgements Herngreen, G.F.W. & de Boer, K.F. 1984: Palynology of the ‘Upper Jurassic’ Central Graben, Scruff and Delfland Groups in the The authors wish to thank the Geological Survey of the Dutch part of the North Sea continental shelf. In: Michelsen, Netherlands (Rijks Geologische Dienst – RGD/NITG) for O. & Zeiss, A. (eds): International Symposium on Jurassic permission to publish the presented data. The authors stratigraphy (Erlangen 1984) 3, 695–714. Copenhagen: are indebted to R. Rijkers, A. Hollen and F. Rispens (all Geological Survey of Denmark. RGD) for providing information on the regional distri- Herngreen, G.F.W. & Wong, Th.E. 1989: Revision of the ‘Late Jurassic’ stratigraphy of the Dutch Central North Sea Graben. bution and petroleum exploration successes in the Geologie en Mijnbouw 68, 73–105. Dutch Jurassic. H.A. van Adrichem Boogaert and M.C. Herngreen, G.F.W., de Boer, K.F., Romein, B.J., Lissenberg, T. & Geluk (RGD) gave valuable comments to the manuscript Wijker, N.C. 1984: Middle Callovian Beds in the Achterhoek, and its precursors. Similarly, the manuscript has bene- eastern Netherlands. Mededelingen Rijks Geologische Dienst fited significantly from earlier discussions with the var- 37, 95–123. ious members of the working group on the Upper Herngreen, G.F.W., Lissenberg, T. & Witte, L.J. 1988: Dinoflag- Jurassic – Lower Cretaceous Stratigraphy for the new ellate, sporomorph, and micropalaeontological zonation of Callovian to Ryazanian strata in the North Sea Central Graben, Stratigraphic Nomenclature of the Netherlands. the Netherlands. 2nd International Symposium on Jurassic stratigraphy (Lisbon 1987) 2, 745–762. Lisbon: Universidade Nova de Lisboa. Herngreen, G.F.W., Smit, R. & Wong, Th.E. 1991: Stratigraphy References and tectonics of the Vlieland Basin, the Netherlands. In: Bodenhausen, J.W.A. & Ott, W.F. 1981: Habitat of the Rijswijk Oil Spencer, A.M. (ed.): Generation, accumulation and produc- Province, onshore, the Netherlands. In: Illing, L.V. & Hobson, tion of Europe’s hydrocarbons. European Association of G.D. (eds): Petroleum geology of the continental shelf of Petroleum Geoscientists Special Publication 1, 175–192. North-West Europe, 301–309. London: Institute of Petroleum. Heybroek, P. 1974: Explanation to tectonic maps of the Nether- Brinkmann, R. 1959: Abriss der Geologie, 8th edition, 360 pp. lands. Geologie en Mijnbouw 53, 43–50. Stuttgart: Enke Verlag. Jensen, T.F., Holm, L., Frandsen, N. & Michelsen, O. 1986: Jurassic Brown, S. 1990: Jurassic. In: Glennie, K.W. (ed.): Introduction to – Lower Cretaceous lithostratigraphic nomenclature for the the petroleum geology of the North Sea, 219–255. Oxford: Danish Central Trough. Danmarks Geologiske Undersøgelse Blackwell Scientific Publications. Serie A 12, 65 pp. Burgers, W.F.J. & Mulder, G.G. 1991: Aspects of the Late Jurassic Kemper, E. 1976: Geologischer Führer durch die Grafschaft and Cretaceous history of the Netherlands. Geologie en Mijn- Bentheim und die angrenzenden Gebiete mit einem Abriss der bouw 70, 347–354. emsländischen Unterkreide, 5th edition, 206 pp. Nordhorn– Cameron, T.D.J., Crosby, A., Balson, P.S., Jeffery, D.H., Lott, G.K., Bentheim: Verlag Heimatverein der Grafschaft Bentheim. Bulat, J. & Harrison, D.J. 1992: United Kingdom offshore Klassen, H. (ed.) 1984: Geologie des Osnabrücker Berglandes, regional report: The geology of the southern North Sea, 152 672 pp. Osnabrück: Naturwissenschaftliches Museum. pp. London: Her Majesty’s Stationery Office for the British Michelsen, O. & Wong, Th.E. 1991: Discussion of Jurassic litho- Geological Survey. stratigraphy in the Danish, Dutch and Norwegian Central Graben areas. In: Michelsen, O. & Frandsen, N. (eds): The

228 Jurassic in the southern Central Trough. Danmarks Geologiske RGD 1995: Geological atlas of the subsurface of the Netherlands. Undersøgelse Serie B 16, 20–28. Explanation to map sheet III, 113 pp. Haarlem: Geological Michelsen, O., Nielsen, L.H., Johannessen, P.N., Andsbjerg, J. & Survey of the Netherlands (RGD). Surlyk, F. 2003: Jurassic lithostratigraphy and stratigraphic Rhys, G.H. (compiler) 1974: A proposed standard lithostrati- development onshore and offshore Denmark. In: Ineson, J.R. graphic nomenclature for the southern North Sea and an out- & Surlyk, F. (eds): The Jurassic of Denmark and Greenland. line structural nomenclature for the whole of the (UK) North Geological Survey of Denmark and Greenland Bulletin 1, Sea. Institute of Geological Sciences Report 74/8, 14 pp. 147–216 (this volume). London: Her Majesty’s Stationery Office. NAM & RGD 1980: Stratigraphic nomenclature of the Netherlands. ’t Hart, B.B. 1969: Die Oberjura- und Unterkreide-Sedimentation Verhandelingen van het Koninklijk Nederlands Geologisch en in den nördlichen und östlichen Niederlanden. Erdöl und Mijnbouwkundig Genootschap 32, 77 pp. (Nederlandse Kohle, Erdgas, Petrochemie 22, 253–261. Aardolie Maatschappij & Rijks Geologische Dienst). Underhill, J.R. & Partington, M.A. 1993: Jurassic thermal doming NITG–TNO 1998: Geological atlas of the subsurface of the and deflation in the North Sea: implications of the sequence Netherlands. Explanation to map sheet X, 142 pp. Haarlem: stratigraphic evidence. In: Parker, J.R. (ed.): Petroleum geol- Netherlands Institute of Applied Geoscience – National ogy of Northwest Europe: proceedings of the 4th conference, Geological Survey. 337–345. London: Geological Society. Partington, M.A., Copestake, P., Mitchener, B.C. & Underhill, J.R. van Adrichem Boogaert, H.A. & Kouwe, W.F.P. (compilers) 1993: Biostratigraphic calibration of genetic stratigraphic 1994–1997: Stratigraphic nomenclature of the Netherlands, sequences in the Jurassic – lowermost Cretaceous (Hettangian– revision and update by RGD and NOGEPA. Mededelingen Ryazanian) of the North Sea and adjacent areas. In: Parker, J.R. Rijks Geologische Dienst 50, sections A–J (sections paginated (ed.): Petroleum geology of Northwest Europe: proceedings independently). of the 4th conference, 371–386. London: Geological Society. Van Wagoner, J.C., Posamentier, H.W., Mitchum, R.M., Vail, P.R., Perrot, J. & van der Poel, A.B. 1987: Zuidwal – a Neocomian gas Sarg, J.F., Loutit, T.S. & Hardenbol, J. 1988: An overview of field. In: Brooks, J. & Glennie, K.W. (eds): Petroleum geology the fundamentals of sequence stratigraphy and key defini- of North West Europe, 325–335. London: Graham & Trotman. tions. In: Wilgus, C.K. et al. (eds): Sea-level changes – an inte- RGD 1991a: Geological atlas of the subsurface of the Netherlands. grated approach. Society of Economic Paleontologists and Explanation to map sheet I, 79 pp. Haarlem: Geological Survey Mineralogists Special Publication 42, 39–45. of the Netherlands (Rijks Geologische Dienst). van Wijhe, D.H. 1987: Structural evolution of inverted basins in RGD 1991b: Geological atlas of the subsurface of the Netherlands. the Dutch offshore. In: Ziegler, P.A. (ed.): Compressional intra- Explanation to map sheet II, 87 pp. Haarlem: Geological plate deformations in the Alpine Foreland. Tectonophysics Survey of the Netherlands (RGD). 137, 171–219. RGD 1993a: Geological atlas of the subsurface of the Netherlands. Wong, Th.E., van Doorn, Th.H.M. & Schroot, B.M. 1989: ‘Late Explanation to map sheet IV, 127 pp. Haarlem: Geological Jurassic’ petroleum geology of the Dutch North Sea Central Survey of the Netherlands (RGD). Graben. Geologische Rundschau 78, 319–336. RGD 1993b: Geological atlas of the subsurface of the Netherlands. Ziegler, P.A. 1990: Geological atlas of western and central Europe, Explanation to map sheet V, 126 pp. Haarlem: Geological 2nd edition, 239 pp. Amsterdam: Elsevier for Shell Internation- Survey of the Netherlands (RGD). ale Petroleum Maatschappij.

Manuscript received 11 September 1995; revision accepted 17 January 1997.

229 LZB-1 et al. Depositional facies Time Stratigraphy S N

(Ma) ) Marl after Roer Valley West Netherlands Broad Fourteens Central Netherlands Lower Saxony Dutch Central Graben Harland Achter- Open marine clay (Cretaceous) Berrias. Graben Basin Basin Basin Basin et al. hoek (1990) 1988 Open marine clay (Jurassic) Global Substages Sequences after Haq ( Valang. KN 140.7 LZB-2.1 KN KN Bituminous marine clay/shale Boreal 1.6 Neomiodon Mb GSS Schill Grund Mb Clay Deep Mb Portlandian

Ryaz. Coevorden Fm Open marine argillaceous greensand 142.8 Tethys Bloemendaal Mb GSP 1.5 Zurich Fm Weiteveen Fm F Scruff Greensand Shallow marine greensand E Kim. GSA Fm 145.6 1.4 Driehuis Mb LZA-21.3 LZA-3 LZA-4 D Clay Coastal sand

1.2 Schieland Gp GSB 147.8 Santpoort C Fm Tithonian Coal-rich coastal plain heterolithics 1.1 Mb Nieuwerkerk Nieuwerkerk B CFT CFO γ−ζ Sandy coastal/fluvial plain heterolithics 4.7 Fm Fm Breeveertien Fm Niedersachsen Gp

A Scruff Group

Schieland Group Fourteens Claystone Mb

Schieland Group Fine-grained coastal plain and lacustrine heterolithics 152.1 Malm 4.6 Friese Front Fm Kimmeridge Clay Fm Kimmeridgian 4.5 Aerdenhout Mb Lagoonal claystones/siltstones 154.7 Kim. β 4.4 4.3 ATBRO Puzzle Hole Fm U. Graben Fm Lacustrine/highly restricted marine carbonates Oxford. α 4.2 CFR M. Graben Fm CMS 157.1 4.1 ATBRU Highly restricted marine salts L. Graben Fm ATBR3 ζ LZA-1 Highly restricted marine anhydrite/carbonates Callov. 3.2 Schieland ATBRM ε Klomps mb Shallow marine sandy limestone 161.3 7 ATBR2 ? ε6 3.1 ATBRL 2.4 2.3 Brabant ? ε5 ATBR1 Fm Abbreviated stratigraphic terms 166.1 Bathonian 2.2 ε1-4 Brabant Formation ATBRO: Oisterwijk Limestone Mb Dogger δ2 Upper Werkendam 2.1 Claystone Mb ATBRU: Upper Brabant Marl Mb

δ1 ATBR3: Upper Brabant Limestone Mb γ ATBRM: Middle Brabant Marl Mb 173.5 Middle Werkendam Mb ATBR2: Middle Brabant Limestone Mb β2-4 1.1 Werkendam Fm ? ATBRL: Lower Brabant Marl Mb Bajocian Lower Werkendam β1 Claystone Mb ATBR1: Lower Brabant Limestone Mb α 178.0 4.6 ζ 4.5 Middle Graben Formation 4.4 CMS: Middle Graben Sandstone Mb

ε2 Friese Front Formation 4.3 Posidonia CFO: Oyster Ground Claystone Mb Shale Fm ε1 CFT: Terschelling Sandstone Mb Aalenian 187.0 δ CFR: Rifgronden Claystone Mb 2 4.2 δ 1 4.1 Weiteveen Formation γ3 3.4 F: Serpulite Mb γ 2 E: Upper Marl Mb γ1 3.3 D: Upper Evaporite Mb 194.5 β3 C: Lower Marl Mb

β2 B: Lower Evaporite Mb

UAB-33.2 UAB-4 Toarcian A: Basal Clastic Mb β1 Aalburg Fm Scruff Greensand Formation α3 GSS: Stortemelk Mb 3.1 203.5 GSP: Scruff Spiculite Mb α2 GSA: Scruff Argillaceous Mb UAB-2 GSB: Scruff Basal Sandstone Mb α1 208.0 Altena Group Rhaetian UAB-1 Sleen Fm KN: Rijnland Gp 209.5 Norian UAA-4 RN RN: Upper Germanic Trias Gp

Fig. 4. Litho-chronostratigraphicLias scheme of the Rhaetian–Ryazanian succession of the five main Jurassic basin systems in the Netherlands: (1) Roer Valley Graben – West Netherlands Basin, (2) Off-Holland Low – Broad Fourteens Basin, (3) Central Netherlands Basin, (4) Ems Low – Lower Saxony Basin and (5) Vlieland Basin, Terschelling Basin and Dutch Central Graben. Abbreviated stage names are given in full in Fig. 1; Berrias., Berriasian. Compiled and modified from van Adrichem Boogaert & Kouwe (1994–1997, sections F, G). Sinemurian Hettangian Pliensbachian Fig. 5.AselectionofdiagnosticbiomarkerhorizonsfortheRhaetian–Valanginian, correlatedwiththeNorthwestEuropeanstand has beenrecalibratedtofitthetime-scaleofHarland divisions asdepictedinthevariousfiguresareusedordertoshow thestratigraphicpositionofsedimentsfoundin in.Cmie n oiidfo a dihmBoar ow 19–97 etosF G). tions. CompiledandmodifiedfromvanAdrichemBoogaert&Kouwe (1994–1997,sectionsF, Time (Ma) 210 205 200 195 190 185 180 175 170 165 160 155 150 145 140 135

Triassic Early Jurassic Middle Jurassic Late Jurassic Cretaceous Stratigraphy Rhaetian

Norian Kimm. Tithonian Berriasian Hettangian Sinemurian Pliensbachian Toarcian Aalenian Bajocian Bathonian Callovian Oxfordian Valanginian Kimmeridgian s.l. Portlandian Ryazanian

base occurrence top occurrence E L E L E MLELM E M L EL‘E’‘L’ E L EL Lias Dogger Malm β α α β α β β ε δ γ δ δ γ γ ε β δ ε

2–4 1–4 3 2 1 2 2 3 1 1 1 2 1 1 2 2 3 1 UAA-4 UAB-1 UAB-2 UAB-3 UAB-4 LZA-1 LZA-2 LZA-3 LZA-4 LZB-1 LZB-2 Sequences 3.2 4.3 4.4 4.5 4.6 1.1 2.1 3.1 3.3 3.4 4.2 3.2 4.4 4.6 4.7 1.1 1.2 1.3 1.4 2.1 1.5 2.2 2.3 1.6 2.3 3.1 4.5 2.2 4.1 4.2 4.3 2.1

2.4 (Haq et al. base acme top acme 4.1 1988) pallasioides primitivus rotunda preplicomphalus albani glaucolithus lamplughi okusensis kerberus ‘oppressus’/anguiformis runctoni icenii stenomphalus albidum Paratollia Polyptychites Dichotomites unnamed fittoni kochi macer suessi marshi planorbis liasicus angulata bucklandi semicostatum turneri obtusum oxynotum raricostatum ibex davoei margaritatus spinatum tenuicostatum serpentinus bifrons variabilis thouarsense dispansum pseudoradiosa aalensis opalinum murchisonae bradfordensis concavum discites laeviuscula propinquans humphriesianum niortense garantiana parkinsoni zigzag tenuiplicatus progracilis subcontractus morrisi hodsoni orbis discus jamesoni rosenkrantzi/regulare macrocephalus calloviense coronatum athleta lamberti cordatum/mariae densiplicatum tenuiserratum serratum/glosense baylei cymodoce mutabilis eudoxus autissiodorensis elegans scitulus wheatleyensis hudlestoni pectinatus jason Standard Ammonite NW European Zonation rare consistent r c ostracod foraminifer et al. c Rhynchodiniopsis regalis;Valvaeodiniumspinosum Ctenidodinium combazii/ornatumplexus Nannoceratopsis spiculata;N.gracilis c Lithodinia jurassica; C. continuum L. scarburghensis L. scarburghensis N. pellucida;S.crystallinum Stephanelytron; S.fasc./penic. E. luridum T. daveyi E. pharo T. apatela Rhaetogonyaulax Dapcodinium priscum Liasidium variabile Luehndea spinosa Scriniocassis weberi Wallodinium cylindricum Nannoceratopsis dictyambonis;N.triceras; Susadinium Parvocysta Meiourogonyaulax valensii c P. pannosum Gonyaulacysta D. spinosum;E.torynum;K.porosispinum B. radiculatum O. patulum r c Bejuia polygonalis Carpathodinium predae S. inritibilum c C. panneum;G.dimorphum G. virgula A. dictyota;P.pannosum Pareodiniaprolongata P. ‘eopelliferum’sensu G. jurassica; P. pannosum Cribroperidinium Muderongia (1989). Kimmeridgian Selected dinoflagellatedatums spp.; disappearances areapproximate sporomorph appearancesand spp.;c (o) (f) r sp.A sp.A; O. patulum Reutlingia spp. sp.A/B; Phallocysta eumekes R. thula RRI(1987) spp.; E. polyplacophorum Wanaea c S. jurassica G. mutabilis; R. aemula; M. extensiva s.l. equals Kimmeridgian c Neoraistrickia truncata;Uvaesporitesargenteaeformis; Calliasporites segmentatus;Lycopodiaciditesrugulatus; Tsugaepollenites pseudomassulae;Zebrasporiteslaevigatus Triancoraesporites reticulatus; Rhaetipollis germanicus;Semiretisporis Densosporites fissus;Lunatisporites rhaeticus; Cingulizonates rhaeticus;Cornutisporites seebergensis; Chasmatosporites major Calliasporites segmentatus Leptolepidites Calliasporites argenteaeformis Neoraistrickia gristhorpensis;Uvaesporites (incl. Ischyosporites variegatus;Staplinisporites Sestrosporites pseudoalveolatus Parvisaccites radiatus Ovalipollis pseudoalatus Cerebropollenites Ricciisporites tuberculatus; Zebrasporites interscriptus Contignisporites problematicus c Trilites Circulina meyeriana Precicatricosisporites Precicatricosisporites Classopollis echinatus/hammeniiplexus c Classopollis Classopollis Aequitriradites; Plicatella Clavifera triplex various c Raistrickisporites brevitruncatus c c Lycopodiumsporitessemimuris Heliosporites altmarkensis Cicatricosisporites Rogalskaisporites cicatricosus Trilobosporites; Kraeuselisporites Concavissimisporites; Coronatisporites spp. Trilobosporites spp.; spp.; Selected sporomorphdatums ; c spp. Densoisporites; Neoraistrickia truncata Sestrosporites pseudoalveolatus spp. ) c spp. Impardecispora; Protocythere pseudopropria Ammovertella cellensis Paranotacythere elongatata Fabanella ansata Galliaecytheridea postsinuata Cypridea carinata Schuleridea juddi Galliaecytheridea teres Mandelstamia sexti Exophthalmocythere gigantea Macrodentina rugulata Eocytheridea eusarca Saracenaria oxfordiana Galliaecytheridea spinosa Galliaecytheridea polita sensu anglico sp. spp .; (o) (o); (o); tubbergensis Kraeuselisporites (o); (o); Mantelliana purbeckensis (f); (o); C. granulosa (o); (f); (o); Cytheropterina triebeli (o); Galliaecytheridea volgaensis Protocythere hannoverana (o) (o); Aaleniella inornata Paranotacythere speetonensis Macrodentina transiens Paralesleya perforata (o); (o); Mandelstamia tumida Galliaecytheridea compressa Klieana dictyota Klieana calyptroides (o) . The terms Lias,DoggerandMalmtheirclassicregionalsub- . Theterms (o) (o); (o) (o)

(o) Netherlands inaEuropeancontextofwell-establishedzona- (o); (o); (o); (o); (o) (o); ard ammonitezonation.TheHaq (o) Cytherelloidea pulchella Ogmoconchella ellipsoidea Ogmoconcha hagenowi Eripleura eleanorae Galliaecytheridea punctata Pleurocythere richteri Oligocythereis fullonica Micropneumatocythere subconcentrica Saracenaria sublaevis Ogmoconcha contractula Wicherella semiora Rhombocythere penarthensis Lutkevichinella Cytherelloidea buisensis Ektyphocythere triebeli Lophodentina pumicosa Klinglerella variabilis Camptocythere praecox Otocythere callosa Camptocythere foveolata Camptocythere media Praeschuleridea decorata Glyptocythere polita Progonocythere polonica Progonocythere stilla Pseudohutsonia tuberosa Frondicularia terquemi Lingulina tenera Kinkelinella persica Fuerbergiella primitiva Pleurocythere regularis Glyptocythere auricula Pleurocythere connexa Lophocythere scabra Lophocythere interrupta Epistomina mosquensis Lophocythere flexicosta Eucytherura horrida Schuleridea triebeli Mandelstamia rectilinea Nophrecythere cruciataoxfordiana Lophocythere multicostata Vernoniella sequana Mandelstamia maculata Pleurocythere impar Ammopalmula infrajurensis Eucytherura costaeirregularis Pseudoperissocytheridea parahieroglyphica Ogmoconcha amalthei Ogmoconchella bispinosa Pleurifera harpa Ljubimovella piriformis Glyptocythere scitula Selected foraminifer/ostracoddatums sp.(o) group(f); (o); (o); (o); (o) (o); (o) (o) (o); (o) (o) (o); (o); (o) (f); Gammacythere ubiquita (o) (o) (o) (o); (f) (o) (o) (o); (o) (o); (o); (f) (o); (o); (o); Aphelocythere kuhni (o); (o); (o) Galliaecytheridea wolburgi (o); (o); Galliaecytheridea dissimilis (o) (o); (o) (o); (o); Glyptocythere tuberodentina Glyptocythere guembeliana Bolivina liasica Fuhrbergiella horrida (o); (o) (o); (f); Marginulina prima Lenticulina quenstedti Bairdia clio (o); (o); Lophodentina lacunosa Nanacythere elegans Nophrecythere cruciata Klinglerella translucens Lingulina teneracollenoti (o) (o) Ektyphocythere betzi Lenticulina foveolata Lophocythere plena Epistomina nuda Trachycythere tubulosa Camptocythere pusilla Gramannicythere bachi Cytherelloidea circumscripta Macrodentina cicatricosa Fuhrbergiella gigantea L. bipartita Gramannella apostolescui (o) (o) (o); (o); (o); (o); (o); Polycope cincinnata (o); group(f) (f) (f) (o) (f) (o) (f) (o); (o) (o) (o) (o) (o) (o) (o); (o) (f); (o); (o); (o); (o); (o) (o); et al (o); (o) . (1988)cyclechart