摘要:

The Earth has replenished its surface with carbon throughout geologic time. The supply may have come from hydrocarbons originally included in the body and outgassing largely through faults in the crust. Combustible gases are frequently released in earthquakes and seem to be an essential part of that phenomenon. New sources of fuel and improved earthquake prediction may come from a better understanding of the processes.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00616.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The Canadian Arctic Islands are underlain by the Cambrian‐Devonian Franklinian geosyncline, which is exposed in several areas, including the Parry islands fold belt, a part of the Paleozoic Arctic fold belt; and by the Mississippian‐Tertiary Sverdrup successor basin. Since 1969, one oilfield has been found in the Parry Islands fold belt and seven gasfields have been found in the Sverdrup basin. Only the gasfields are considered here.A total of 12.0 Tcf of proved and probable marketable gas reserves has been established in Early Jurassic and Triassic sandstones of the Sverdrup basin. These are mainly in structural traps, although some stratigraphic trapping has been established. Two of the fields–Hecla and Drake Point–are giants. Most of the gas reserves are in the Early Jurassic Borden Island Formation. Prospects for the future, largely offshore, are considered to be ve

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00617.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Island arcs are commonly depicted as smoothly curved or sinuous structures. This presentation almost certainly is incorrect. Most island arcs, perhaps all, are composed of more or less straight segments whose trend changes direction suddenly at specific hinge or boundary zones; these zones seem to consist of multiple transverse faults. Each straight segment itself is cut by transverse faults. The presence of the transverse structural systems is evident from geological and geophysical data.Examples of segmentation include island arcs in Indonesia, the Philippines, Solomons, New Hebrides, Kuril‐Kamchatka, Lesser Antilles, Central America, Mexico, Tonga, Alaska, Japan, Chile, Andaman‐Nicobar Islands, New Britain, Marianas, Greece, and the Himalayas. The fracture system may be related to structural, morphological, or movement aspects of an underthrusting slab, or it may be the result of movement in the backdeep or of the overthrusting sheet in general. Some of the transverse faults may be old ones that have been rejuvenated within the island‐arc area.Transverse structural systems seem to have had a pronounced effect on the petroleum accumulations of island‐arc regions, both from a stratigraphic and structural viewpoint; they therefore affect petroleum‐exploration procedures. Such systems are also likely to be found in ancient basins that went through an island‐arc stage. Knowledge of the segmentation of island arcs should aid future

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00618.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

In Permian Rotliegend aeolian sandstones in the Dutch sector of the North Sea, kaolinite dominates over poorly crystallised, pore‐lining illite in areas of shallow burial. Fibrous, bridging illite dominates over kaolinite in the areas of deeper burial.This distribution of diagenetically formed interstitial clay minerals coincides with a regional permeability trend. Higher permeabilities occur in the area where kaolinite dominates over poorly crystallised, pore‐lining illite; lower permeabilities occur in the area where fibrous, bridging illite dominates over kaolin

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00619.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Theories on crustal evolution have been developed from geologic investigations in orogenic belts and in the less deformed foreland or epeirogenic areas. In this paper, it is suggested that, because one global mechanism must govern the evolution of both orogenic and epeirogenic areas, the two must be closely related. Because the interpretation of orogenic belts is complicated so greatly by extreme deformation, metamorphism, and loss of data through erosion, it is logical to seek interpretative leads on their orogenic style and timing by precise observations and analyses of structural “monitors” in the less complex borderlands.The three foreland monitors considered are: (1) block faulting, (2) salt diapirism, and (3) volcanicity. All three monitors support the concept that tectonic pulses during measurable geologic time have been short lived and synchronous around the globe. They also indicate that the dominant structural stress which triggered these tectonic pulses has been extensional.If extensional stress also has governed the evolution of orogenic belts, then the interpretations which advocate fundamental vertical tectonics, secondary gravity sliding, and intrusion by mantle diapirism are more acceptable than those which advocate crustal shortening and compression. Moreover, if tensional tectonics has governed both orogenic and epeirogenic areas as well as the ocean‐spreading centers, then the hypothesis of global expansion is more logical and harmonious than the popular and heuristic assumptions on crustal subduction.For the successful resolution of regional tectonic problems, geologists must free themselves of dogmatic constrictions and broad generalisations. As in the exploration for hydrocarbons, what is needed is a scrupulous and patient attention to geologic detail, set within the most precise time framework attai

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00620.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A radically new method of structural analysis is proposed which relates the deformation of all rocks to a three‐dimensional model of close‐packed spheres and deformation ellipsoids. All rocks exist under variable stress conditions and are deformed, but the principles of three‐dimensional deformation are poorly understood by many geologists and geophysicists. An understanding of rock deformation in three dimensions is a very valuable aid in geological interpretation and in the search for hydrocarbons. The method proposed provides the geologist, geophysicist and associated scientific disciplines with a means of understanding complex, three‐dimensional deformation and attempts to explain all deformational phenomena from mud cracks to plate tectonics. Deformation is a spherical harmonic waveform which, although complex in detail, is intrinsically no more mathematically complicated than the reciprocal of the square root of three. The analysis is illustrated by examples of “compressive” deformation from the Tertiary fold belt of Spitsbergen and the “tensional” or “gravitational” deformation in the Viking Graben of the

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00621.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

“Recent Advances in Geomathematics. An International Symposium”. Computers and Geology, Vol. 2, Edited by D. F. Merriam.“The Geology of the Lake District”, ed. F.

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00622.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00623.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00624.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0141-6421    

DOI:10.1111/j.1747-5457.1979.tb00625.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY