scholarly journals Early Cretaceous (Neocomian-Cenomanian) Palynomorphs

1985 ◽  
Vol 4 (1) ◽  
pp. 131-149 ◽  
Author(s):  
B. Thusu ◽  
J. G. L. A. Van Der Eem
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Age Determination ◽  
Marine Environments ◽  
Dinoflagellate Cysts ◽  
Shallow Marine ◽  
The North ◽  
Close Proximity ◽  
Pollen And Spores ◽  
Early Late

Abstract. INTRODUCTIONThis study is primarily concerned with the Neocomian to Aptian palynomorphs recorded in selected exploration wells (See Fig. 9). In order to document a complete Early Cretaceous microfloral succession in the studied wells, a reconnaissance of Aptian to Early Cenomanian palynomorphs was also undertaken. Details of the results from this younger interval appear in a later section.Palynomorph assemblages vary in preservation and character. To the north, sandstone, siltstone and shale deposited in shallow-marine environments, contain well-preserved assemblages of dinoflagellate cysts, pollen and spores which can be used for stage-level age determination. A majority of the samples analysed, however, contain moderate numbers of dinoflagellate cysts, but fewer miospores. The abundance of land derived detritus indicates the relatively close proximity of the shoreline. In the central and southern parts of the study area, sandstone and siltstone that are deposited in non-marine, fluvial, lacustrine or lagoonal environments show a general paucity of well-preserved palynofloras. Miospores of stratigraphic value are generally rare or absent although the majority of the samples are dominated by land derived detritus.PALYNOMORPH SUCCESSIONThe majority of the wells from northern Cyrenaica show a hiatus at the Jurassic Cretaceous boundary. Late Neocomian or Aptian sediments occur immediately above Middle or early Late Jurassic sediments. Well preserved Neocomian palynomorphs were recorded in wells A1-36, B1-36, Bla-18 and A1-45. The stratigraphical ranges of palynomorphs presented on the plate explanations are local ranges and are based on the studied intervals only. A preliminary palynological zonation of Late Jurassic (Late Kimmeridgian) to . . .

scholarly journals Early Cretaceous

1982 ◽  
Vol 8 ◽  
pp. 45-49
Author(s):  
Jens Morgen Hansen ◽  
Arne Buch
Keyword(s):  
North Sea ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Late Jurassic ◽  
Significant Feature ◽  
Marine Clay ◽  
The North ◽  
Marine Sand ◽  
The North Sea ◽  
Early Late

The Early Cretaceous sea primarily covered the same basinal regions as the Late Jurassic sea but, late in the Early Cretaceous the sea also covered Late Jurassic land masses. During Early Cretaceous time the topography of the North Sea region became gradually buried. The following major transgression comprises the transition Early/Late Cretaceous. At the Jurassic/ Cretaceous transition, the Late Cimmerian unconformity is a significant feature (fig. 24), known from large parts of the North Sea region. The subsequent transgression and sedimentation of marine clay (the Valhall Formation), and marine sand (the LC-1 Unit), started late in Late Jurassic. Therefore, the formations described in the present chapter also comprise sediments of Late Jurassic age. Thicknesses of the Lower Cretaceous sediments are given in fig. 15.

Late Jurassic-Early Cretaceous sandstones of Algan formation: composition, genesis, sources (North-West of Koryak Highland)

2020 ◽  
pp. 48-58
Author(s):  
M. U. Gushchina ◽  
A. V. Moiseev ◽  
M. I. Tuchkova
Keyword(s):  
Early Cretaceous ◽  
High Speed ◽  
Late Jurassic ◽  
Small Distance ◽  
Marine Environments ◽  
North West ◽  
The North ◽  
Medium Speed ◽  
Mineralogical Compositions

The article presents the results of studying the petrographic and mineralogical compositions of the sandstones of the Algan formation. Sandstones represented by pelitic-fine-medium-grained quartz-feldspar lithic arenites. Two tectonically combined sandstones lithotypes found. Lithotypes were formed in two heterochronous basins by high-speed and medium-speed turbidity flows, in moderately deep marine environments, in a relatively small distance from the coast. Sedimentation was near the deltas and prodeltas. The sources of these basins were different, related to the heterochronous volcanic areas in the north of the researched region.

scholarly journals Middle – Late Jurassic (Late Bathonian – Tithonian) Palynomorphs

1985 ◽  
Vol 4 (1) ◽  
pp. 113-129 ◽  
Author(s):  
B. Thusu ◽  
J. O. Vigran
Keyword(s):  
Marine Environment ◽  
Marine Sediments ◽  
Late Jurassic ◽  
Precambrian Basement ◽  
Shallow Marine ◽  
Sedimentary Environments ◽  
The North ◽  
Close Proximity ◽  
Jurassic Rocks ◽  
Shallow Marine Sediments

Abstract. INTRODUCTIONJurassic palynomorph assemblages have been recovered in numerous wells in northeast Libya. Jurassic rocks reflect changing sedimentary environments which have greatly influenced the composition of the palynological assemblages.In the northernmost area, Jurassic sediments unconformably overlie the Palaeozoic or Triassic and show a mixed marine and continental influence. In the northeastern part of the area thicker and deeper water marine sediments are known, while shallow marine sediments overlie the platform facies immediately to the south. Pollen and miospores are fairly well preserved and are dominant in most samples. Dinoflagellate cysts are richly represented especially in the deposits of the north and northeast. Most samples contain abundant variably sorted cuticular debris and structured wood fragments. This significant influx of terrestrial debris together with the associated palynomorph assemblages indicate deposition in a shallow marine environment in close proximity to the shoreline for most of the Jurassic deposits in the northern area.In the central and southern region, sandstone, silt stone and red shale deposited in non-marine fluvial to lacustrine or lagoonal environment, unconformably overlie the metamorphic or igneous Precambrian Basement. These sediments show a general lack of well preserved palynomorphs. Miospores, though present are generally long ranging and terrestially derived detrital kerogen dominate the assemblages.MICROFLORAL SUCCESSIONMiospore assemblages present in most of the samples investigated are dominated by small gymnosperm pollen. Classopollis spp., Exesipollenites spp., Sphaeripollenites spp., and nonaperturate pollen assigned to Araucariacites spp. Saccate pollen assigned to Concentrisporites spp., Perinopollenites spp., Callialasporites spp., and Inaperturopollenites spp., are often common . . .

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

Origin and genesis of Late Jurassic to Early Cretaceous granites of the North Qinling Terrane, China

Lithos ◽  
2019 ◽  
Vol 336-337 ◽  
pp. 242-257 ◽  
Author(s):  
Yuan-Shuo Zhang ◽  
Wolfgang Siebel ◽  
Song He ◽  
Yan Wang ◽  
Fukun Chen
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
The North ◽  
North Qinling

Late Jurassic - Early Cretaceous paleoenvironmental evolution of the Transbaikal basins (SE Siberia): implications for the Mongol-Okhotsk orogeny

2017 ◽  
Vol 188 (1-2) ◽  
pp. 9 ◽  
Author(s):  
Marc Jolivet ◽  
Anastasia Arzhannikova ◽  
Andrei Frolov ◽  
Sergei Arzhannikov ◽  
Natalia Kulagina ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Tectonic Setting ◽  
Alluvial Fan ◽  
Crustal Thickening ◽  
Compressive Deformation ◽  
Transbaikal Region ◽  
Meandering River ◽  
The North

The Late Jurassic - Early Cretaceous tectonic evolution of SE Siberia was marked by the closure of the Mongol-Okhotsk ocean. While this geodynamic event led to compressive deformation and denudation in a wide area encompassing the North-Altay, Sayan and Baikal Patom ranges, it was contemporaneous to widespread extension from the Transbaikal region situated immediately north of the suture zone to the Pacific plate, affecting eastern Mongolia and northeastern China. In this study we review the paleontological and sedimentological data available in the Russian literature and provide new macro-floral and palynological data from the Mesozoic sediments of three Transbaikal basins. These data are used to describe the paleoenvironmental and paleoclimatic evolution of the Transbaikal area in order to assess the topographic evolution of the region in relation with the closure of the Mongol-Okhotsk ocean. We establish that the Transbaikal basins evolved in a continuously extensional tectonic setting from at least the Early-Middle Jurassic to the Early Cretaceous. The associated sedimentary environments are characterized by retrogradation from alluvial fan–braided river dominated systems prevailing during the Early to Middle Jurassic initial opening of the basins to meandering river– lacustrine systems that developed during the Late Jurassic - Early Cretaceous interval. No evidence of high relief topography was found and we conclude that, while compression and denudation occurred in the North Altai, Sayan and Patom ranges, in the Transbaikal region, the docking of the Mongolia-North China continent to Siberia was a “soft collision” event, possibly involving a major strike-slip displacement that did not lead to an orogenic event implying strong compressive deformation, crustal thickening and topography building.

scholarly journals Palaeoecology and depositional environments of the Tendaguru Beds (Late Jurassic to Early Cretaceous, Tanzania)

Fossil Record ◽  
2002 ◽  
Vol 5 (1) ◽  
pp. 19-44 ◽  
Author(s):  
M. Aberhan ◽  
R. Bussert ◽  
W.-D. Heinrich ◽  
E. Schrank ◽  
S. Schultka ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Jurassic ◽  
Tidal Flats ◽  
Depositional Environments ◽  
Coastal Plains ◽  
Fair Weather ◽  
Shallow Marine ◽  
Plant Fossils ◽  
Sand Bar ◽  
Formed Part

The Late Jurassic to Early Cretaceous Tendaguru Beds (Tanzania, East Africa) have been well known for nearly a century for their diverse dinosaur assemblages. Here, we present sedimentological and palaeontological data collected by the German-Tanzanian Tendaguru Expedition 2000 in an attempt to reconstruct the palaeo-ecosystems of the Tendaguru Beds at their type locality. Our reconstructions are based on sedimentological data and on a palaeoecological analysis of macroinvertebrates, microvertebrates, plant fossils and microfossils (ostracods, foraminifera, charophytes, palynomorphs). In addition, we included data from previous expeditions, particularly those on the dinosaur assemblages. <br><br> The environmental model of the Tendaguru Beds presented herein comprises three broad palaeoenvironmental units in a marginal marine setting: (1) Lagoon-like, shallow marine environments above fair weather wave base and with evidence of tides and storms. These formed behind barriers such as ooid bar and siliciclastic sand bar complexes and were generally subject to minor salinity fluctuations. (2) Extended tidal flats and low-relief coastal plains. These include low-energy, brackish coastal lakes and ponds as well as pools and small fluvial channels of coastal plains in which the large dinosaurs were buried. Since these environments apparently were, at best, poorly vegetated, the main feeding grounds of giant sauropods must have been elsewhere. Presumably, tidal flats and coastal plains were visited by dinosaurs primarily during periods of drought. (3) Vegetated hinterland. Vegetation of this environment can only be inferred indirectly from plant material transported into the other depositional environments. Vegetation was dominated by a diverse conifer flora, which apparently formed part of the food source of large herbivorous sauropods. Evidence from various sources suggests a subtropical to tropical palaeoclimate, characterised by seasonal rainfall alternating with a pronounced dry season during the Late Jurassic. In Early Cretaceous times, sedimentological and palaeontological proxies suggest a climatic shift towards more humid conditions. <br><br> Die Tendaguru-Schichten von Tansania in Ostafrika (Oberjura bis Unterkreide) sind als Lagerstätte oberjurassischer Dinosaurier seit nahezu einem Jahrhundert weltweit bekannt. Anhand von sedimentologischen und paläontologischen Daten, die während der Deutsch-Tansanischen Tendaguru Expedition 2000 im Typus-Gebiet der Tendaguru-Schichten gewonnen wurden, werden Paläo-Ökosysteme rekonstruiert. Grundlage der Rekonstruktionen sind die Auswertung sedimentologischer Daten sowie die paläo-ökologische Analyse von Makroinvertebraten, Mikrovertebraten, pflanzlichen Fossilien und Mikrofossilien (Ostrakoden, Foraminiferen, Charophyten, Palynomorphen). Darüber hinaus werden Informationen über Dinosaurier berücksichtigt, die bei früheren Expeditionen gewonnen wurden. <br><br> Das hier vorgestellte Ablagerungsmodell der Tendaguru-Schichten umfaßt drei Teilbereiche eines randlich marinen Sedimentationsraumes, die wie folgt gekennzeichnet werden können: (1) Lagunen-artige, marine Flachwasserbereiche, die oberhalb der Schönwetter-Wellenbasis lagen und unter deutlichem Einfluß von Gezeiten und Stürmen standen. Sie waren vom offenen Meer durch Barrieren, wie Ooidbarren und siliziklastischen Sandbarrenkomplexen, getrennt und wiesen einen leicht schwankenden Salzgehalt auf. (2) Ausgedehnte Wattgebiete und flache Küstenebenen. Dort befanden sich niedrig-energetische, brackische Strandseen und Teiche sowie Tümpel und kleinere Flußrinnen, in denen die großen Dinosaurier eingebettet wurden. Da diese Lebensräume bestenfalls dürftig bewachsen waren, müssen die Nahrungsquellen und der eigentliche Lebensraum der riesigen Sauropoden anderswo gelegen haben. Vermutlich wurden die Wattgebiete und Flachküsten von Dinosauriern vorrangig in den Trockenzeiten aufgesucht. (3) Bewachsenes Hinterland. Die Vegetation dieses Lebensraumes kann nur indirekt aus Pflanzenresten erschlossen werden, die in die anderen Ablagerungsraume transportiert wurden. Die Vegetation wurde von einer diversen Koniferenflora dominiert, die zumindest teilweise die Nahrungsgrundlage der großen, herbivoren Sauropoden bildete. Sedimentologische und paläontologische Indikatoren sprechen für ein subtropisches bis tropisches Klima wahrend der späten Jurazeit mit einem jahreszeitlichen Wechsel von Regenfällen und ausgeprägten Trockenzeiten. In der frühen Kreidezeit deutet sich ein Wechsel zu starker humiden Bedingungen an. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20020050103" target="_blank">10.1002/mmng.20020050103</a>

scholarly journals Phanerozoic Vertical Movements in Morocco

2020 ◽  
Author(s):  
Remi J.G. Charton
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Numerical Models ◽  
Vertical Movements ◽  
The Past ◽  
Basement Rocks ◽  
Exhumation Rates ◽  
Early Late

Our understanding of the Earth’s interior is limited by the access we have of its deep layers, while the knowledge we have of Earth’s evolution is restricted to harvested information from the present state of our planet. We therefore use proxies, physical and numerical models, and observations made on and from the surface of the Earth. The landscape results from a combination of processes operating at the surface and in the subsurface. Thus, if one knows how to read the landscape, one may unfold its geological evolution.In the past decade, numerous studies have documented km-scale upward and downward vertical movements in the continental rifted margins of the Atlantic Ocean and in their hinterlands. These movements, described as exhumation (upward) and subsidence (downward), have been labelled as “unpredicted” and/or “unexpected”. ‘Unpredicted’ because conceptual, physical, and numerical models that we dispose of for the evolution of continental margins do not generally account for these relatively recent observations. ‘Unexpected’ because the km-scale vertical movements occurred when our record of the geological history is insufficient to support them. As yet, the mechanisms responsible for the km-scale vertical movements remain enigmatic.One of the common techniques used by geoscientists to investigate the past kinematics of the continental crust is to couple ‘low-temperature thermochronology’ and ‘time-temperature modelling’. In Morocco alone, over twenty studies were conducted following this approach. The reason behind this abundance of studies and the related enthusiasm of researchers towards Moroccan geology is due to its puzzling landscapes and complex history. In this Thesis, we investigate unconstrained aspects of the km-scale vertical movements that occurred in Morocco and its surroundings (Canary Islands, Algeria, Mali, and Mauritania). The transition area between generally subsiding domains and mostly exhuming domains, yet poorly understood, is discussed via the evolution of a profile, running across the rifted continental margin (chapter 2). Low-temperature thermochronology data from the central Morocco coastal area document a km-scale exhumation between the Permian and the Early/Middle Jurassic. The related erosion fed sediments to the subsiding Mesozoic basin to the northwest. Basement rocks along the transect were subsequently buried between the Late Jurassic and the Early Cretaceous. From late Early/Late Cretaceous onwards, rocks present along the transect were exhumed to their present-day position.The post-Variscan thermal and geological history of the Anti-Atlas belt in central Morocco is constrained with a transect constructed along strike of the belt (chapter 3). The initial episode occurred in the Late Triassic and led to a km-scale exhumation of crustal rocks by the end of the Middle Jurassic. The following phase was characterised by basement subsidence and occurred during the Late Jurassic and most of the Early Cretaceous. The basement rocks were then slowly brought to the surface after experiencing a km-scale exhumation throughout the Late Cretaceous and the Cenozoic. The exhumation episodes extended into the interior of the African tectonic plate, perhaps beyond the sampled belt itself. Exhumation rates and fluxes of material eroded from the hinterlands of the Moroccan rifted margin were quantified from the Permian (chapter 4). The high denudation rates, obtained in central Morocco during the Early to Middle Jurassic and in northern Morocco during the Neogene, are comparable to values typical of rift flank, domal, or structural uplifts. These are obtained in central Morocco during the Early to Middle Jurassic and in northern Morocco during the Neogene. Exhumation rates for other periods in northern to southern Morocco average around ‘normal’ denudation values. Periods of high production of sediments in the investigated source areas are the Permian, the Jurassic, the Early Cretaceous, and the NeogeneThe Phanerozoic evolution of source-to-sink systems in Morocco and surroundings is illustrated in several maps (chapter 5). Substantial shifts in the source areas were evidenced between the central and northern Moroccan domains during the Middle-Late Jurassic and between the Meseta and the Anti-Atlas during the Early-Late Cretaceous. Finally, the mechanisms responsible for the onset and subsistence of the unpredicted km-scale vertical movements are discussed (chapter 6). We propose that a combination of the large-scale crustal folding, mantle-driven dynamic topography, and thermal subsidence, superimposed to changes in climates, sea level and erodibility of the exposed rocks, were crucial to the timing, amplitude, and style of the observed vertical movements.The km-scale vertical movements will continue to be studied for years to come. Expectantly, this Thesis will deliver sufficiently robust grounds for further elaborated and integrated studies in Morocco and beyond.

Palynostratigraphy and palaeoclimate of the Valanginian– Cenomanian subsurface succession in Hamza-1X well, Matruh Basin, Egypt

2020 ◽  
Vol 297 (2) ◽  
pp. 173-191 ◽  
Author(s):  
Ibrahim M. Ied ◽  
Sameh S. Tahoun ◽  
Walid A. Makled
Keyword(s):  
Age Determination ◽  
Pollen Grains ◽  
Point Of View ◽  
Western Desert ◽  
Dinoflagellate Cysts ◽  
Spores And Pollen ◽  
Dinoflagellate Cyst ◽  
The North ◽  
Assemblage Zone ◽  
Stratigraphic Succession

Diverse palynomorph assemblages of spores, pollen grains and dinoflagellate cysts have been yielded from the palynological analyses of 115 ditch cutting samples covering the Valanginian– Cenomanian succession encountered in Hamza-1X well, Matruh Basin, north Egypt. The complex sit- uations in the north Western Desert requires more revisited palynozones for better understanding of the subsurface successions therein. Consequently, the first downhole palyno-events will be very helpful in solving some issues concerning the age determination and correlation. Seventy palynomorph species (47 spores and pollen grains; 23 dinoflagellate cyst species) were identified from all the productive samples which used to divide the studied succession into numerous sporomorph and dinoflagellate biozones based on the last occurrence datum for the recovered marker taxa. Four sporomorph inter- val biozones and six dinoflagellate cyst interval biozones were differentiated from the same studied stratigraphic succession. The four sporomorph biozones are presented, in ascending order as follows: Aequitriradites spinulosus and Impardecispora apiverrucata Interval Zone (late Valanginian– early Barremian), Pilosisporites trichopapillosus I. Z. (late Barremian), Murospora florida I. Z. (early Aptian–late Aptian), and Elaterosporites klaszii I. Z. (early Albian– early Cenomanian). The seven dinoflagellate cysts biozones are Muderongia simplex I. Z. (late Valanginian–early Barremian), Pseudoceratium anaphrissum I. Z. (late Barremian– early Aptian), Cribroperidinium edwardsii I. Z. (early Aptian), Subtilisphaera perlucida I. Z. (late Aptian), Oligosphaerdium complex I. Z. (early– late Albian), Dinopterygium cladoides and Coronifera oceanica Assemblage Zone (early Cenomanian). From the palaeoclimatic point of view, the studied interval could be differentiated into two climatic intervals; the lower arid interval that comprises the Alam El Bueib Formation and dominated by the arid xerophyte elements like Sphaeripollenites and Classopollis. The upper humid interval represents the Alamein, Dahab, Kharita and Bahariya formations that is dominated by the humid hygrophyte elements, such as Murospora, Crybeolsporites, Elaterosporites, Afropollis and Deltoidospora.

AN EARLY CRETACEOUS SOURCE ROCK IN THE KENDREW TERRACE, DAMPIER SUB-BASIN?

1996 ◽  
Vol 36 (1) ◽  
pp. 477 ◽  
Author(s):  
S. Ryan-Grigor ◽  
C. M. Griffiths
Keyword(s):  
Source Rock ◽  
North Sea ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Large Scale ◽  
Free Water ◽  
Organic Content ◽  
Source Rocks ◽  
The North ◽  
Northern North Sea

The Early to Middle Cretaceous is characterised worldwide by widespread distribution of dark shales with high gamma ray readings and high organic contents defined as dark coloured mudrocks having the sedimentary, palaeoecological and geochemical characteristics associated with deposition under oxygen-deficient or oxygen-free bottom waters. Factors that contributed to the formation of the Early to Middle Cretaceous 'hot shales' are: rising sea-level, a warm equable climate which promoted water stratification, and large scale palaeogeographic features that restrict free water mixing. In the northern North Sea, the main source rock is the Late Jurassic to Early Cretaceous Kimmeridge Clay/Draupne Formation 'hot shale' which occurs within the Viking Graben, a large fault-bounded graben, in a marine environment with restricted bottom circulation and often anaerobic conditions. Opening of the basin during a major trans-gressive event resulted in flushing, and deposition of normal open marine shales above the 'hot shales'. The Late Callovian to Berriasian sediments in the Dampier Sub-basin are considered to have been deposited in restricted marine conditions below a stratified water column, in a deep narrow bay. Late Jurassic to Early Cretaceous marine sequences that have been cored on the North West Shelf are generally of moderate quality, compared to the high quality source rocks of the northern North Sea, but it should be noted that the cores are from wells on structural highs. The 'hot shales' are not very organic-rich in the northern Dampier Sub-basin and are not yet within the oil window, however seismic data show a possible reduction in velocity to the southwest in the Kendrew Terrace, suggesting that further south in the basin the shales may be within the oil window and may also be richer in organic content. In this case, they may be productive source rocks, analogous to the main source rock of the North Sea.

Sign in / Sign up

Export Citation Format

Share Document