THE REGIONAL GEOLOGY OF THE BONAPARTE GULF TIMOR SEA AREA

1974 ◽  
Vol 14 (1) ◽  
pp. 77 ◽  
Author(s):  
Robert A. Laws ◽  
Gregory P. Kraus
Keyword(s):  
Late Cretaceous ◽  
Late Jurassic ◽  
Oil And Gas ◽  
Upper Jurassic ◽  
Structural Configuration ◽  
Structural Pattern ◽  
Source Areas ◽  
Timor Sea ◽  
Early Palaeozoic ◽  
Sea Area

The present structural configuration of the Bonaparte Gulf-Timor Sea area is essentially the result of Mesozoic and Tertiary fragmentation of a once relatively simple Permo-Triassic Basin. A northwest-southeast Palaeozoic structural grain in the southeastern portion of the area resulted from early Palaeozoic faulting, possibly tied to aborted rift development. This faulting effectively controlled sedimentation throughout the Phanerozoic. Pronounced northeast-southwest Jurassic to Tertiary structural trends dominate the central and northern area, paralleling the present edge of the continental shelf and swinging south southwest into the northern extension of the Browse Basin. Post-Palaeozoic epeirogenies which had the greatest effect on the regional structural pattern occurred in the mid-Jurassic, Early Cretaceous, within the Eocene and in the Plio-Pleistocene.The Kimberley and Sturt Blocks flanking the basin to the south and east constituted the most important source areas for clastic sedimentation throughout the Phanerozoic. Periodic contributions during the Mesozoic were derived from a postulated source to the northwest in the vicinity of the present-day Timor Trough.The maximum thickness of Phanerozoic sediments present within the Bonaparte Gulf-Timor Sea area exceeds 50,000 ft (15,000 m). Early Palaeozoic to Carboniferous evaporites, carbonates and clastics are unconformably overlain by a thick sequence of Permian deltaic sediments in the southeastern Bonaparte Gulf Basin. This is succeeded by a Triassic to Middle Jurassic transgressive-regressive clastic sequence, grading northwestward to marginal marine and marine clastics and carbonates. The Permian to mid-Jurassic sediments are unconformably overlain by Upper Jurassic sands and shales, mainly fluvial in the southeast and north, becoming more marine westward. These clastics are everywhere succeeded by a monotonous sequence of Cretaceous shales and shaly limestones followed by a generally north to northwesterly thickening wedge of Tertiary carbonates and minor elastics.Hydrocarbon shows have been noted offshore in rocks of Carboniferous, Permian, Late Jurassic, Late Cretaceous and Eocene age. Porous clastics in conjunction with thick and laterally-extensive, organically-rich shales are present within the Palaeozoic and Mesozoic sequences. These sediments, in association with fault- and diapir-related anomalies and stratigraphic plays, combine to make certain provinces of the Bonaparte Gulf-Timor Sea area prospective in the search for viable oil and gas reserves.

scholarly journals POLA ANOMALI GAYABERAT DAERAH TALIABU-MANGOLE DAN LAUT SEKITARNYA TERKAIT DENGAN PROSPEK MINYAK BUMI DAN GAS

2016 ◽  
Vol 12 (2) ◽  
pp. 65
Author(s):  
Saultan Panjaitan ◽  
Subagio Subagio
Keyword(s):  
Gravity Anomaly ◽  
Late Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Oil And Gas ◽  
Research Area ◽  
Black Shales ◽  
Reservoir Rocks ◽  
Gas Seepage ◽  
Anomaly Pattern

Anomali gayaberat di daerah penelitian merupakan anomali tertinggi di Indonesia, secara umum dikelompokkan ke dalam 2 (dua) satuan, yaitu: kelompok anomali gayaberat 160 mGal hingga 260 mGal membentuk pola rendahan/cekungan anomali, dan kelompok anomali gayaberat 260 mGal hingga 620 mGal membentuk pola tinggian anomali. Anomali sisa 0 mGal hingga 5 mGal membentuk tinggian anomali, diduga merupakan gambaran antiklin dengan diameter 10 – 15 kilometer. Perangkap struktur migas di daerah Minaluli, Madafuhi dan Lekosula Pulau Mangole berdekatan dengan lokasi rembesan migas, sehingga diusulkan untuk dilakukan pemboran eksplorasi. Sedangkan di Pulau Taliabu, Tolong, Pena, Samuya dan Teluk Jiko masih perlu dilakukan penambahan data. Batuan reservoir terdiri dari batupasir dan batugamping Formasi Tanamu berumur Kapur Akhir, menempati daerah beranomali sisa 0 mGal hingga 5 mGal, dengan rapat massa batuan sekitar 2.65 gr/cm³. Batuan induk adalah Formasi Buya umur Jura Tengah - Jura Akhir dari serpih hitam dengan rapat massa 2.71 gr/cm³, dan dapur migas terbentuk di sekitar daerah beranomali sisa -4 mGal hingga -28 mGal yang membentuk sub-cekungan di utara lepas pantai Pulau Mangole. Kata kunci: gayaberat, dapur minyak, cekungan, migas, serpih hitam, anomali sisa, rapat massa, antiklin, batuan induk. The gravity anomaly of research area is the highest anomaly in Indonesia, generally it can be grouped into 2 (two) units, that are 160 mGal up to 260 mGal anomaly groups formed low anomaly pattern, and 260 mGal up to 620 mGal anomaly groups formed high anomaly pattern. 0 mGal to 5 mGal residual anomaly formed high anomaly pattern, it is interpreted as anticline with diameter are 10-15 kilometers. The trap oil and gas structures of this area at Minaluli, Madafuhi, and Lekosula are near the location of oil and gas seepage, that is propose to explore and drill in that area. Whereas in Taliabu Island, Tolong, Pena, Samuya, and Jiko Gulf still need increasing datas. Reservoir rocks consist of sandstones and limestones of Tanamu Formations were Late Cretaceous age, that occupied the location of 0 mGal to 5 mGal residual anomaly with density 2.65 g/cm ³. Hostrock are Buya Formation are Middle Jurassic - Late Jurassic from black shales with density 2.71 g/cm³, and kitchen oil were formed in the area - 4 mGal to -28 mGal residual anomaly that formed low anomaly in the northern offshore of Mangole Island. Keyword: gravity, oil kitchen, basin, oil and gas, black shales, recidual anomaly, density, anticline, hostrocks.

Source Rocks of Somalia – A Regional Assessment

2016 ◽  
Author(s):  
Daniel Trümpy ◽  
Jan Witte ◽  
Immanuel Weber ◽  
João P. Da Ponte Souza
Keyword(s):  
Source Rock ◽  
Late Cretaceous ◽  
Late Jurassic ◽  
High Heat ◽  
Upper Jurassic ◽  
Source Rocks ◽  
Long Distance ◽  
The North ◽  
Geological Information ◽  
Well Data

ABSTRACT In total, some 60 wells have been drilled onshore and less than 10 offshore Somalia*, none of which in deep water. Several prospective basins remain undrilled, such as the offshore Jubba and Mid Somali High basins and the onshore Odewayne basin. In view of the gas discoveries offshore Mozambique and Tanzania, and also of encouraging results offshore Kenya (sub-commercial oil discovery Sunbird-1) and in Madagascar, the Somalian offshore and onshore basins were re-evaluated. As to the Somali onshore basins, the extension of the Yemeni Jurassic and Cretaceous rifts into Somalia highlights their prospectivity. Seeps abound (Odewayne and Nogal basins) and some wells encountered good shows. Late Jurassic and Upper Cretaceous marine shales are source rock candidates. Gas in the area of Mogadishu may be associated with the Early Triassic Bokh Fm. source rock. Seeps in western Somalia are rare, and may result either from long-distance migration out of the Calub Graben or from locally mature Lower Cretaceous or Upper Jurassic. We establish an inventory of proven and possible source rock occurences in Somalia by integrating publicly available data on slicks and seeps, geological and gravity maps, literature data, well data and geological information from adjoining basins. Our data indicate that in the Somali part of the Gulf of Aden, high heat-flow may critically affect the Late Jurassic source rock. However, Late Cretaceous or even Eocene sources may be locally oil-mature. The presence of source rocks on the Somali Indian Ocean margin remains presently speculative. Abundance of slicks in the area south of Mogadishu may not relate to hydrocarbons. Of more interest are reported isolated slicks further to the north, in deeper waters of the Mogadishu and Mid-Somalia High Basins. These slicks may be related to Lower/Mid-Jurassic, Late Jurassic, Late Cretaceous or Eocene sources. Analysis of onshore seeps in northern Somalia (Nogal, Daroor, Odewayne basins), integrated with seismic data, will allow to determine the origin of these oils and an assessment of the size of prospective kitchen areas. In the offshore, 3D-Basin-modelling will be required to determine which areas are prospective for gas or, especially, for oil.

scholarly journals Distributional patterns of ?Mawsoniidae (Sarcopterygii: Actinistia)

2014 ◽  
Vol 86 (1) ◽  
pp. 159-170 ◽  
Author(s):  
RAPHAEL MIGUEL ◽  
VALÉRIA GALLO ◽  
JUAN J. MORRONE
Keyword(s):  
Southern Hemisphere ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
Upper Triassic ◽  
Late Triassic ◽  
Tectonic Events ◽  
Distributional Patterns ◽  
Track Analysis

Mawsoniidae are a fossil family of actinistian fish popularly known as coelacanths, which are found in continental and marine paleoenvironments. The taxon is considered monophyletic, including five valid genera (Axelrodichthys, Chinlea, Diplurus, Mawsonia and Parnaibaia) and 11 genera with some taxonomical controversy (Alcoveria, Changxingia, Garnbergia, Heptanema, Indocoelacanthus, Libys, Lualabaea, Megalocoelacanthus, Moenkopia, Rhipis and Trachymetopon). The genera restricted to the Northern Hemisphere (Diplurus and Chinlea) possess the oldest records (Late Triassic), whereas those found in the Southern Hemisphere (Mawsonia, Axelrodichthys, and Parnaibaia) extend from Late Jurassic to Late Cretaceous, especially in Brazil and Africa. We identified distributional patterns of Mawsoniidae, applying the panbiogeographical method of track analysis, and obtained three generalized tracks (GTs): GT1 (Northeastern Newark) in strata of the Newark Group (Upper Triassic); GT2 (Midwestern Gondwana) in the Lualaba Formation (Upper Jurassic); and GT3 (Itapecuru-Alcântara-Santana) in the Itapecuru-Alcântara-Santana formations (Lower Cretaceous). The origin of Mawsoniidae can be dated to at least Late Triassic of Pangaea. The tectonic events related to the breakup of Pangaea and Gondwana and the evolution of the oceans are suggested as the vicariant events modeling the distribution of this taxon throughout the Mesozoic.

scholarly journals Hydrocarbon geological aspects of subsidence curves: interpretations based on released wells in the Danish Central Graben

1983 ◽  
Vol 31 ◽  
pp. 159-169
Author(s):  
Jens Morten Hansen ◽  
Naja Mikkelsen
Keyword(s):  
Late Cretaceous ◽  
Late Jurassic ◽  
Present Model ◽  
Upper Jurassic ◽  
Early Tertiary ◽  
Late Neogene ◽  
Well Data

The lithostratigraphy of the Danish Central Graben sequence is briefly outlined and the lithostratigraphic subdivision tabulated for 23 released wells. A simple subsidence model for the periode from Triassic to Recent is established exclusively with reference to the presented well data. The model points to pro-nounced changes in the rate of subsidence through Mesozoic and Cenozoic times with major changes taking place during late Jurassic and late Neogene. Based on the subsidence model it is suggested, that possible sourcerocks of Carboniferous or older ages were mature by late Cretaceous time. The presum­ably most promising sourcerock of the Central Graben, the upper Jurassic J-4 unit, reached the hydro­carbon generating level during early Tertiary in the deeper parts of the Graben whereas extensive hydro­carbon generation in the shallower parts did not reach a maximum before Neogene according to the present model.

scholarly journals Salt and fault interactions in the northeastem Danish Central Graben: observations and inferences

1993 ◽  
Vol 40 ◽  
pp. 197-255
Author(s):  
J. A. Korstgard ◽  
I. Lerche ◽  
T. E. Mogensen ◽  
O. Thomsen
Keyword(s):  
Thermal History ◽  
Late Jurassic ◽  
Vitrinite Reflectance ◽  
Upper Jurassic ◽  
Structural Configuration ◽  
Early Tertiary ◽  
Fault Interactions ◽  
Well Data ◽  
Zechstein Salt ◽  
Reflectance Data

Korstgard, J. A., Lerche, I., Mogensen, T. E. & Thomsen, R. 0.: Salt and fault interactions in the northeastem Danish Central Graben: observations and inferences. Bulletin of the Geological Society of Denmark, Vol. 40, pp. 197-255. Copenhagen, 1993-12-30. Salt structures in the Spgne Basin and the Tail End Graben, the northeastern part of the Danish Central Graben, have been studied using a 1/2-1 km spaced seismic grid together with publically available well data. The investigated area has been divided into three main basin areas: the northern part of the Spgne Basin, a plateau area; the southern part of Spgne Basin, a shallow halfgraben; and the Tail End Graben, a deep halfgraben. These basins are flanked by the Ringkpbing-Fyn High and the Manda! High. Pre-Zechstein, and/or Pre-Permian normal faults, together with the shape of reflectors in the northernmost Spgne Basin, indicate an Early, possibly Late Carbon­iferous, extension phase. The structural configuration of the sediments above the Zechstein salt pillows in the shallow halfgraben part of Spgne Basin, when compared with the structural configuration of the sediments in the much deeper Tail End Graben, indicates deeply buried salt pillows in the Tail End Graben. The salt structures fall into two basic groups, graben boundary salt pillows/diapirs and salt pillows/diapirs updip in halfgrabens. The evolution of these Zechstein salt structures is complex and intimately related to fault activity. Development of Triassic depocentres was primarily controlled by halokinesis with large thicknesses of sediments being deposited in primary and secondary rim synclines in the Spgne Basin. Middle Jurassic rift initiation was associated with synrift sediments along the Coffee Soil Fault and Late Jurassic rifting caused a separation of the Spgne Basin and the Tail End Graben, and the formation of a ramp dipping to the south at the Coffee Soil Fault, which was· a pathway for sediments from the deeply eroded Ringkpbing-Fyn High footwall. This ramp has high sand potential. In the Early Cretaceous the Spgne Basin and Tail End Graben were separate depositional areas and the position of the Lower Cretaceous sediments were controlled by the Late Jurassic footwall uplift of the Manda! High, the southernmost part of the Spgne Basin, and the Ringkpbing-Fyn High. Upper Cretaceous deposits were the first sediments to overlay the Ringkpbing-Fyn High and the Manda) High footwalls, indicating a change of the structural framework and in the Late Cretaceous and Early Tertiary inversion occurred in the area with renewed halokinesis, especially in the Tail End Graben. Continued halokinesis in the Late Miocene is indicated by the position of Late Miocene channels. Using vitrinite reflectance measurements from the Lulu-I well, drilled on top of a salt structure, it is possible to determine the excess maturity caused by the focusing of heat due to the higher thermal conductivity of salt. A method is presented for assessing the time of onset of diapirism and salt flow-speed. The method is based on calculation of the thermal anomaly surrounding a rising salt diapir. For a given salt speed, predicted vitrinite reflectance values are calculated and compared with the observed values at given depths. In this way salt migration rates are determined by forward modelling. The method can easily be tailored to thermal indicators other than vitrinite reflectance, thereby enhancing the resolution of the thermal history, and constraining both the onset of salt rise as well as the speed. In addition geohistory, thermal history, source capacity and oil generation have been examined in the northwestern part of the Danish Central Graben using a one-dimen­sional fluid flow-compaction model. The burial history suggests that this part of the Danish Central Trough developed through three stages of subsidence, a Late Jurassic differential stage, a Late Cretaceous-Early Tertiary uniform stage and a Late Miocene­Quaternary uniform stage. Pseudo-wells "drilled" on seismic sections in areas without well data are used to improve the spatial distribution of wells. The palaeotemperature and palaeoheat flow have been modelled by inversion of vitrinite reflectance data. The inversion was carried out on wells with available vitrinite reflectance data and was based on known bottom hole temperatures, some temperature measurements with depth and the surface temperature. The thermal history assessed by inversion of vitrinite reflectance data gives a consistently cooler past; the available data's resolution of the thermal history is also discussed. The modelled maturation history of the Upper Jurassic shale in terms of vitrinite reflectance suggests that the shale reached maturity some 5-50 Ma ago. A geochemical study of the Upper Jurassic shales shows that these shales contain a mixture of type II and type III kerogens and have good to excellent source potential. Modelling of the hydrocarbon generation data indicates that the peak generation took place some time between 10 Ma BP and the present day. Possible migration paths are determined from modelled excess fluid pressure, and four areas of possible accumulation of hydrocarbons are indicated. The hydrocarbon potentials of the areas are evaluated and an area along the eastern boundary fault between the Tail End Graben and the Ringk!Zlbing-Fyn High is suggested as a target for further explora­tion.

scholarly journals Isolated pliosaurid teeth from the Albian–Cenomanian (Cretaceous) of Annopol, Poland

2017 ◽  
Vol 67 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Daniel Madzia ◽  
Marcin Machalski
Keyword(s):  
Cross Section ◽  
Late Cretaceous ◽  
Type Species ◽  
Late Jurassic ◽  
Morphological Variability ◽  
Original Material ◽  
Tooth Crown ◽  
Similar Morphology ◽  
Faunal Turnover ◽  
Early Late

AbstractBrachauchenine pliosaurids were a cosmopolitan clade of macropredatory plesiosaurs that are considered to represent the only pliosaurid lineage that survived the faunal turnover of marine amniotes during the Jurassic- Cretaceous transition. However, the European record of the Early to early Late Cretaceous brachauchenines is largely limited to isolated tooth crowns, most of which have been attributed to the classic Cretaceous taxon Polyptychodon. Nevertheless, the original material of P. interruptus, the type species of Polyptychodon, was recently reappraised and found undiagnostic. Here, we describe a collection of twelve pliosaurid teeth from the upper Albian-middle Cenomanian interval of the condensed, phosphorite-bearing Cretaceous succession at Annopol, Poland. Eleven of the studied tooth crowns, from the Albian and Cenomanian strata, fall within the range of the morphological variability observed in the original material of P. interruptus from the Cretaceous of England. One tooth crown from the middle Cenomanian is characterized by a gently subtrihedral cross-section. Similar morphology has so far been described only for pliosaurid teeth from the Late Jurassic and Early Cretaceous. Even though it remains impossible to precisely settle the taxonomic distinctions, the studied material is considered to be taxonomically heterogeneous.

Radiolarian assemblages of Middle and Late Jurassic to early Late Cretaceous (Cenomanian) ages from an olistolith record pelagic deposition within the Bornova Flysch Zone in western Turkey

2012 ◽  
Vol 183 (4) ◽  
pp. 307-318 ◽  
Author(s):  
Ugur Kagan Tekin ◽  
M. Cemal Göncüoglu ◽  
Seda Uzuncimen
Keyword(s):  
Late Cretaceous ◽  
Middle Jurassic ◽  
Late Jurassic ◽  
Western Turkey ◽  
Oceanic Basin ◽  
Platform Margin ◽  
Lowermost Part ◽  
Early Late ◽  
Radiolarian Assemblages

Abstract The Bornova Flysch Zone (BFZ) in NW Anatolia comprises several olistoliths or tectonic slivers, representing various parts of the Izmir-Ankara ocean. Radiolarian assemblages extracted from one of the olistoliths of the BFZ, cropping out along the Sögütlü section, to the NE Manisa city, were studied in detail. The lowermost part of the section contains latest Bajocian – early Callovian radiolarian taxa, followed by radiolarian assemblages indicating Late Jurassic to early Late Cretaceous (Cenomanian) ages. Previous studies reveal that the Izmir-Ankara oceanic basin was initially opened during late Ladinian – early Carnian. The new radiolarian data obtained from this olistolith reveals that relatively condensed, and possibly more or less continuous, pelagic sedimentation took place during the late Middle Jurassic to early Late Cretaceous in a non-volcanic oceanic basin closer to the Tauride-Anatolide platform margin.

Calculation of Technical Characteristics of the Technical Fleet Vessels Involved in Ensuring Safety of the Offshore Facilities of Oil and Gas Complex

2021 ◽  
pp. 7-13
Author(s):  
S.V. Matsenko ◽  
◽  
V.M. Minko ◽  
A.A. Koshelev ◽  
V.Yu. Piven ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil Pollution ◽  
Raw Materials ◽  
Experimental Studies ◽  
Industrial Safety ◽  
Theoretical Studies ◽  
Physical Processes ◽  
Oil Spill Response ◽  
Sea Area

Violation of industrial safety rules during the operation of offshore facilities for the production, storage and transportation of the hydrocarbon raw materials leads in the most cases to pollution of the marine environment with oil and its components. The works on localization and elimination of such pollution are carried out with the help of vessels of the technical support fleet and booms. When developing oil spill response plans at such facilities, a calculated determination of the technical characteristics of vessels and booms is required that are sufficient to carry out the planned activities. The basic design principles for determining the towing capacity of the technical fleet vessels involved in the localization and elimination of oil and oil product spills by trawling methods are given in the article. The calculation is based on theoretical studies performed by the authors of the physical processes occurring during the movement of objects of a mobile trawling order in the sea area. The results obtained during the course of theoretical studies were confirmed by the experimental studies carried out by the authors personally using the real pieces of equipment in the actual development of tasks for training spill containment by trawling. As a result, the empirical dependencies were obtained and experimentally confirmed, which can be used to calculate technical characteristics of the ships as part of the mobile orders and anchor systems as part of stationary orders intended for the localization and elimination of oil pollution. These results can be used, among other things, for the calculated substantiation of the technical characteristics of the technical fleet vessels designed to ensure safety of the offshore facilities for production, storage, and transportation of the hydrocarbon raw materials.

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