ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00798.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00799.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The sedimentary rock sequence in the oilfield areas of Interior Oman ranges from the Late Proterozoic through Paleozoic, Mesozoic and Tertiary. A number of major gaps or changes in sedimentation are recognised, and these punctuate a subdivision into major rock units ranked as groups. Eleven named groups are recognised: in stratigraphic order from oldest, Huaf (Upper Proterozoic), through Haima (Lower Paleozoic), Misfar (Devonian), Haushi and Akhdar (Carboniferous to Triassic), Sahtan (Jurassic), Kahmah (Lower Cretaceous), Wasia (“Middle Cretaceous”), Aruma (Upper Cretaceous), Hadhramaut (Paleogene) to Fars (Neogene). Most of these groups are further subdivided and 35 named formations are described giving lithologic characteristics, boundaries, inferred age span and variability. These descriptions, together with reference well sections indicating wire‐line log characteristics, provide a sufficient basis for consistent future use of the rock units.Hydrocarbon occurrence within this sedimentary sequence is primarily controlled by the presence of good impermeable sealing units, particularly those of sufficient thickness to be least breached by faulting. Seven important sealing units are recognised, ranging from the evaporites of the Huaf Group to the basal shale of the Hadhramaut Group.Commercial hydrocarbon accumulations are retained by all these seals. Reservoirs are in both carbonate and clastic units, and in South Oman are commonly in much older units than the seal, which overlines unconfor

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00800.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The petroleum geochemistry of Oman provides a picture of considerable variey, since crude oils and their source rocks are found both throughout the country and throughout the stratigraphic column from the Infra‐Cambrian to the Tertiary. This paper reviews the geological history history of the area and places the petroleum geochemistry within the geological context.The oils can be geochemically classified into five groups. Three groups can be related to god oil source rocks found in the pre‐Cambrian Huqf Group, the Silurian Safiq and the Cretaceous Natin Formation. Another group of oils probably originates from the Upper Jurassic Diyab Formations, while the fifth group of crudes (named ‘Q’) cannot be correlated to a known source rock, but is inferred to have originated from an unsampled Huqf level.The “Huqf oils” are those that have been correlated to known Infra‐Cambrian Huaf source rocks, and are characterized by a strong C29sterane predonominance and very light carbon isotope values of around‐36.0%. In contrast, the ‘Q’ crudes, drived from the unknown source are characterized by a C27strerane predominance and carbon istope ratios of around ‐30.5%. Both the Huaf and ‘Q’ crudes also contain a series of characteristic compounds referred to as the ‘X’ compounds (all isomers of methyle and dimethyl alkanes). Oils reasoned to originate from Silurian Safiq source rocks have a week C29sterane precominance, a significant content of rearranged steranes and carbon isotope ratios of ‐30.5%. The oils thought to originate from the Jurassic Diyab Formation have a similar sterane distribution but heavier carbon isotope values of around ‐26.5%. Finally, the crude oils from the mid‐Cretaceous Naith Formation source rocks are characteirzed by steranes with an equivalent distribution of C27, C28and C29isomers, and carbon isotope values of around ‐26.9%.These variations in biomarker distributions and carbon isotope values are sufficiently distinct to ensure a high degree of certai

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00801.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The most massive basal diamictite of the Murbat Sandstone Formation exhibits many sedimentary features which indicate its subglacial deposition. Some of the most important features are: (1)straited and grooved sandstone slivers within the diamictete;(2)striated and faceted clasts; (3)small stratified sandstone lenses within the diamictite; (4)“dropstones” or “out‐of‐size clasts” in the shale; and (5) the large lateraal and vertical extent of the diamictite.The overlying sequence of the Murbat Sandstone Formation consits of an alternating succession of conglaomerate and sandstone followed by silstone and shale, whose sedimentary structures, however, suggest their deposition in deeper‐water basins.The Murbat Sandstone Formation has been assigned to various ages ranging from Infra‐Cambrian to Ordovician by different workers, in view of its isolated occurence and the absence of flora and fauna. The Metal Mining Agency of Japan, however, has dated the Murbat Sandstone Formation as Permo‐Carboniferous, as it uncomfomably overlies Lower Carboniferous dikes of the crystalline Basement. The dikes have been dated b

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00802.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The stratigraphic sequence of the “Middle” Cretaceus Wasia Group in the Arabian Gulf, and the terminology used, is reviewed. Type sections and synonyms are established for the succession in the United Arab Emirates. An historical introduction provides a key to the understanding of the varied formational and member names in currnet use.Facies distribution maps show tha shallow‐water, predomantly carbonate belts extend across the whole region. Two clastic‐carbonate cycles are apparent in the NE part of the Gulf, the lower Nahr Umr‐Mauddud cycle and an upper Wara‐Mishrif cycle. The Upper cycle is surrounds a slightly deeper intracratonic basin which developed in late Albian‐Earllly Ce

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00803.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00804.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Book reviewed in this article:“Development of the oil and gas resources of the UK”(1987). Editor: M.J. Robinson.“The Athabasca oil sands: Northern Resource Exploration 1875–1951”, by B. G. Ferguson.“Fundamentals ofpetroleum maps”: by D.P. McElroy.“Profession: Geologue petrolier”, by AIain Perrodon.“Principles ofphysical sedimentolog

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00805.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00806.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1988.tb00807.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY