ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00377.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Detailed organic geochemistry has been performed on a large number of Lower Mississippian‐Upper Devonian Bakken shales from the North Dakota portion of the Williston Basin, and 28 oils mainly from Mississippian Madison Group rocks from different basinal areas. Here we report results of Rock‐Eval pyrolysis and vitrinite reflectance (Ro) analyses. Variable paleoheat flows in the Williston Basin caused the threshold of intense hydrocarbon generation to occur at different depths in different basinal areas. In higher paleogeothermal gradient basinal areas, this event occurred at depths of 7,650‐8,000 ft, and at 10,000 ft or deeper in lower paleogeothermal gradient areas of the Basin. Distinct organic metamorphic imprints in Williston Basin sediments were also caused by extreme, but variable, paleoheat flows in the basin, as well as secondary migration of crude oils from deep basinal source areas. The high paleoheat flows are postulated as being due to a Late Cretaceous — Paleocene aborted rift event. Only a small volume of Bakken shales in restricted areas of the Williston Basin was responsible for the oil found reservoired in Mississippian Madison Group rocks. However, this small shale volume has been responsible for a relatively large amount of crude oil.R0profiles in the Tertiary through Middle Jurassic rocks in the Williston Basin had steep, linear Roversus depth gradients, with strong reversals of R0values occurring in the Lower Jurassic rocks. The lower Mesozoic through Paleozoic rocks of the Basin had strongly suppressed R0values compared to the values in the Tertiary through Middle Jurassic rocks. This was especially true of the R0values in the Bakken shales. This R0suppression was due to a change in organic matter (OM) type from oxygen‐rich terrestrially derived OM in the younger rocks, to a hydrogen‐rich marine derived OM in the deeper, older rocks. The threshold of intense oil generation (TIHG) occurred in the Bakken shales of the Williston Basin at R0values somewhere between 0.9 and 1.7% (best estimate 0.9), as would be read in oxygen‐rich OM. Much higher burial temperatures (and consequently R0values) than usually held to be necessary were required for both the TIHG as well as mainstage hydrocarbon generation in the Bakken shales. These results are most likely applicable in general to source rocks with hydrogen‐rich OM. The data of this study have major implications to petroleum exploration as well as to petroleum reso

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00378.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A significant contribution to regional studies in the Amazonas Basin has been provided by the morphostructural analysis of MSS‐LANDSAT and SLAR imagery. The interpretation of remote sensing data led to the detection of many morphostructural anomalies in the Upper Amazonas Basin. A comparison between these anomalies and the available geological and geophysical data permitted the definition of two distinct morphostructural domains in this region. The first comprises a set of E‐W anomalies, located in a thinner sedimentary cover portion of the Upper Amazonas Basin. This feature was tentatively attributed to a prominent basement hinge line. The second morphostructural domain embraces anomalies situated where the sedimentary pile exceeds 1,600 m. In this domain, many anomalies seem to be related to ENE‐striking reverse faults. These morphostructural anomalies are arranged along ENE and E‐W aeromagnetic trends forming morphostructural trends.Analysis of MSS‐LANDSA T and SLAR imagery near the boundary between the Middle and Lower Amazonas basins indicates that several morphostructural anomalies are aligned in well‐defined directions, also suggesting the presence of morphostructural trends. These trends, often striking ENE, lie among zones with sharp magnetic gradients interpreted as expressions of basement compositional boundaries. Such morphostructural trends are also found near positive small‐wavelength magnetic anomalies, interpreted as possible grabenty

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00379.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The surface appearance and nature of lineaments showing on Landsat images are described, together with their likely causes. A computer model, based on the finite element method, is employed to show that the strain and stress effects over a deep underlying vertical fault are conducive to the development of two classes of faults, which are usually observed at the Earth's surface as lineaments. Some aspects of the involvement of these failure zones in mineral and petroleum prospecting, water supply and engineering geology are outlined.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00380.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A study of surface sections of Upper Jurassic rock units near the city of Riyadh has revealed a total thickness of 500 m. These rock units are the Tuwaiq Mountain Limestone, Hanifa Formation, Jubaila Limestone, Arab Formation and Hith Anhydrite. The characteristic microfacies of Tuwaiq Mountain Limestone include spicular biomicrites in the lower part of the formation, and corals, stromatoporoids and algal biomicrites in the upper part. The characteristic microfacies of the Hanifa, Jubaila and Arab Formations include spicular biomicrites with some argillaceous shales alternating with pelsparities and oosparites. Conglomeratic micrites, dolomites and breccia are found in the upper Jubaila Limestone and the Arab Formation.The total thickness of these rock units increases in the east to more than 900 m where the Arabian and Gotnia Basins are defined. Central Saudi Arabia is best described as being the site of differential carbonate shelf deposition during Upper Jurassic time. Intra‐shelf basins with euxinic conditions were formed. Over these basins, petroleum source rocks were deposited within each rock uni

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00381.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Evidence has accumulated steadily during recent years to show that ocean basins are quite young, certainly younger than Paleozoic and PreCambrian. The most common mechanism invoked to explain the relatively youthful age of ocean basins is through sea‐floor spreading, i.e. by the theory of plate‐tectonics; however, the Author believes that it can be explained more logically by a process of “oceanization”, for which clear evidence was shown in 149 of the first 493 DSDP† boreholes. The oceans began to form during the Middle Jurassic (the oldest marine strata penetrated in the boreholes), about 170 MM years‡ ago. Beginning in the Paleogene, the oceans began to deepen more rapidly. This deepening was accompanied by the effusion of great thicknesses of plateau basalt. The sinking process was made possible by the thickening of the asthenosphere beneath the ocean basins, a process which is continuing towards the continents as these become “oceanized”. It is to be expected that the entire process will be completed within the next 30

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00382.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Anhydrite, gypsum and halite evaporites of Middle Miocene age occurring in the Gulf of Suez area constitute more than 50% of the total rock components. They are intercalated mainly with shales and also subordinate carbonate and sandstone layers. Examination of several evaporite samples under both binocular and petrographic microscopes reveals the presence of inclusions of various types hosted by gypsum crystals. Solid inclusions are composed mainly of minute calcareous particles, fine pyrite crystals and residual organic matter, while liquid inclusions, which are more frequent, exist in a uniphase or biphase state. A light hydrocarbon in the form of oil or gas constitutes one of these phases, while the other is a brine. Most of these inclusions are of primary origin and have been developed during the growth of the hosted minerals.Based on the assemblage of these inclusions, it can be assumed that the evaporitic environment of deposition, with its reducing condition and high salinity, is favourable for the generation of oil from accumulated organic matter. Also, the presence of a carbonate mineral trapped by gypsum indicates the possible mixing of marine water with a brine of restricted occurrence.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00383.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00384.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00385.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Energy for the USA “Energy for ourselves and our posterity”, edited by R. L. Perrine and W. G. Ernst.CO2flooding in EOR “Carbon dioxide flooding: basic mechanisms and project design”, by M. A. Klins.“Biomarkers”“Fossil fuel biomarkers: Applicatons and spectra”, by R. P. Phelp.Preferred orientations “Preferred Orientation in Deformed Metals and Rocks: An Introduction to Modern Texture Analysis” edited by Hans‐Rudolph Wenk.Synthetic fuels “Handbook of Synfuels Technology”, by R. A. Meyers.Cycles in time “Geological and cosmogenic cycles” by F. Benkö.Oil industry phraseology “Handbook of Oil Industry Terms and Phrases”, D. R. Langenkamp.Golden Adventure “A golden adventure: the first 50 years of Ultramar”, by P. Atterbury and J. MacKenzie“Story of the Earth”“The story of the Earth”, by P. Cattermole and P. Moore.Great Oil Discoveries “Histoire des grandes découvertes pétrolières”, by Alain Perrodon.“Encyclopedia of Well‐Logging”“Encyclopedia of Well‐Logging” by R. Desbrandes.Index of Conodonts “A stratigrap

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1986.tb00386.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY