ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00122.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The Perth Basin is localised by reactivation of Neoproterozoic shear zones on the western margin of the Archaean Yilgarn Craton in Western Australia. While Ordovician to Silurian sandstones were deposited in the northern Perth Basin, the earliest sediments elsewhere are Middle Carboniferous to Permian in age. A sinistral transtensional regime, during which the main architecture of the basin was established, developed during NE‐SW extension between Greater India and Western Australia in the Permo‐Triassic. NW‐SE shortening with continued NE‐SW extension resulted in sinistral transpression in the late‐Early to Middle Triassic. Sag‐phase sedimentation in the LateTriassic followed this oblique rifting event.An analogy may be made between the Perth Basin and the Permo‐Carboniferous to Jurassic Karoo basins in southern and central Africa and Madagascar. Deposition of the Karoo sequence took place within pull‐apart and transtensional basins resulting from sinistral reactivation of basement shear zones. The Indian Gondwana Supergroup, and an equivalent sequence in Antarctica, were deposited within normal fault‐bounded graben. The Late Paleozoic to Early Mesozoic formation of the Perth Basin, the Karoo basins of Africa and Madagascar, and the Gondwana basins of India was due to intraplate stress resulting from convergence along the Panthalassa margin of Gondwanaland. Late‐Early to Middle Triassic compressional events in all basins mark terminal collision along the Panthalassa margin.The latest Triassic to Early Jurassic marks a new rifting event due to regional east‐west to WNW‐ESE extension, producing dextralplus normal displacements on many NW‐to NNW‐striking structures, and essentially normal displacements on north‐ to NNE‐striking faults. NW‐SE extension during the Upper Jurassic culminated in the NW separation of Greater India and the formation of oceanic crust in the Neocomian, and resulted in the superposition of structures developed in a dextral transtensional regime. Conjugate strike‐slip faults and minor thrust faults formed during the post‐Neocomian, with approximately north‐south compression and east‐west extension. Precambrian gneisses, granitoids and metasediments of SW Western Australia have been deformed during basin development, and dole rite dyke intrusion during the Carboniferous to Middle Triassic is restricted to these terranes.The sequence of events proposed herein for the Perth Basin is in agreement with the tectonic framework of a large portion of Gondwanaland. A better knowledge of the structural history of the Perth Basin may aid the interpretation of seismic and remote‐sensing data in the

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00123.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Three wells in the Seychelles offshore indicate the existence of four potential source‐rock intervals within the Mesozoic succession. Two of these originated during the rift phase that eventually cleaved Gondwana into Eastern and Western blocks — namely, Middle Triassic lacustrine mudstones, and Early/Middle Jurassic deltaic‐lagoonal mudstones. The other two source‐rock intervals were deposited on passive marine shelves during continental drift phases — namely, Late Jurassic to Early Cretaceous mudstones and siltstones during the East‐West Gondwana drift, and Maastrichtian to Paleocene mudstones during the later Seychelles‐India drift.These source rocks are dominated by terrestrial organic matter. Although TOCs are generally good (greater than 1.0%) and range to excellent (7.82%), potential hydrocarbon yields are generally only poor to fair (less than 6 kg HC/tonne of rock). One good potential yield of 10 kg/tonne has been measured. Maturity data (R0and Tmax) indicate that, in the wells, the youngest source rock is immature, while the oldest lies in the gas “window”. The Jurassic/Cretaceous source rocks, on the other hand, lie within the oil “window”.Analyses of numerous beach‐stranded tarballs that are believed to be of indigenous origin reveal, in addition to a source dominated by terrestrial organic matter, the presence of a source rock dominated by marine algal organic matter. Such a source rock may have developed during a Middle Jurassic phase of shallow‐marine carbonate deposition, which shows some affinity to source‐rock quality, and is characterized by an oolitic marker limestone in each well. This oolitic limestone is also a component fades of the carbonate succession that contains the prolific oil‐prone source

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00124.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A thick succession of sedimentary rocks, comprising mainly Paleozoic shallow‐marine and fluvial deposits, and Mesozoic and Paleogene marine carbonates, with subordinate elastics and evaporites, occurs in Jordan. These are preserved in several basins, including: Late Paleozoic inverted basins with thick, Infra‐Cambrian to Silurian successions in the south, east and NE; and younger, Late Cretaceous and/or Tertiary basins in the centre and west, in which Mesozoic marine shelf sediments and/or thick, rift‐related Neogene sediments are well‐developed.Two regional, organic‐rich source‐rock levels occur. They comprise Upper Ordovician/ Lower Silurian shales in the SE half of the country, and Upper Cretaceous, bituminous chalky marls in the western/central sectors; the former range from immature in the SW to locally over‐mature in the NE, whereas the latter are mainly immature, except where deeply buried, as in the Jordan Valley/Dead Sea rift and part of the Azraq rift. Subordinate source‐rock levels occur in the Triassic and Middle Cretaceous. Numerous hydrocarbon indications, including seeps and floating asphalt blocks, occur in the Dead Sea area and have been correlated with the Upper Cretaceous source rocks.In spite of these positive indications, only 13 exploration wells have been drilled since drilling first began in the mid‐1950s. The Natural Resources Authority (NRA) has established modest oil and gas production in two fields, mainly through the drilling of well clusters in encouraging areas. Hydrocarbons potential, however, remains good, with play concepts related to the major source levels. Detailed local and regional analytical studies, together with extensive and sophisticated seismic acquisition and processing/reprocessing, are required, however, prior to further drilling, with clear and separate strategies for

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00125.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The petroleum geology of Cambodia has been studied less than has that of the neighbouring countries in Indochina. Nevertheless, the results of recent geological, remote‐ sensing and limited seismic investigations (the latter on the Cambodian Shelf area of the Gulf of Thailand) have allowed identification of sedimentary basins favourable for hydrocarbons exploration (both on‐ and offshore), and, consequently, the delineation of prospective areas. Six possibly oil‐ and gas‐bearing basins have been identified, namely: the Siam (northern portion: in the Gulf of Thailand), Tonle Sap, Khorat (southern portion), Preah, Chung and Svairieng

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00126.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

This paper provides an overview of the current state of knowledge concerning the inclusion and transformation of nitrogen in sedimentary organic matter (SOM). The main focus is on petroleum‐forming systems, although some mention is also given to coa

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00127.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The ultimate oil and gas resources of the Niagaran pinnacle‐reef belt of northern Michigan, and the likely outcome of future exploration drilling in this play, were estimated using the Arps‐Roberts discovery process model. For each of ten field‐size classes, the parameters of the model are the ultimate number of fields, and a discovery efficiency coefficient (DEC). The parameters are derived from the actual historic exploration record, consisting of a time‐ordered list of exploration drilling and the sizes of the field discoveries. The data‐base consisted of 539 fields that were discovered during 1968–1982 by the drilling of 1,965 new‐field wildcats. The parameters were estimated both by nonlinear least‐squares curve fitting, and by a heuristic “back‐forecasting” calibration procedure. The DECs were found to increase with field size. Within the historic data, the model's emulation was shown to be excellent. The ultimate recoverable oil and gas‐reserves of the belt are estimated at about 1,200 million brls oil‐equivalent (MM brls o.e.), predicted to be distributed in some 920 fields. Of this amount, 1,030 MM brls, reservoired in 539 fields, had already been discovered by the end of 1982. All the fields in the three largest size‐classes were duly discovered by end‐1986. The approximately 200 MM brls undiscovered by that date were believed to reside in about 380 small fields, more than half of which are smaller than 0.25 MM brls. The play is clearly in a very mature stale, and the cost per barrel of finding new rese

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00128.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00130.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00131.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Book reviewed in this article:“AAPG Treatise of Petroleum Geology”, Reprint Series. Volume 16, Formation Evaluation 1; volume 17, Formation Evaluation II both compiled by N.H. Foster and E.A. Beaumont“Foreland Basins and Fold Belts”, edited by R.W. Macqueen and D.A

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1994.tb00132.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY