R.J. Schroder, 1983. "Structural Interpretation of Line P81-U4, Amadeus Basin, Northern Territory, Australia", Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces, A. W. Bally
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The Amadeus Basin is an intracratonic basin of some 50,000 sq km (19,305 sq mi) at the geographic center of Australia. Line P81-U4 is a dip line over a faulted anticlinal feature close to the McDonnell ranges, which fringe the northern margin of the basin. Hydrocarbons were discovered within the basin at Mereenie oil field, Palm Valley gas field, Ooraminna-1, and Dingo-2. Line P81-U4 is located 50 km (31 mi) northeast of the Mereenie oil field. The reservoir rock at Mereenie is the Pacoota Sandstone. The locality diagram shows the seismic line with respect to mapped outcrop.
Stratigraphic section in the Amadeus basin is of late Proterozoic to Early Paleozoic age. The Bitter Springs Formation to Base Mereenie Sandstone is an interbedded paralic and deep marine sequence containing clastics, evaporites, carbonates, and glacigene sediments. Formations that have a major bearing on the structural style are the evaporitic Bitter Springs and Chandler formations (Wells et al, 1970). Evidence for Bitter Springs diapirism is documented at Stokes Pass Diapir (McNaughton et al, 1968) with which the Undandita anticlinal anomaly is on trend.
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Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces
Until a few decades ago, structural and regional geology were traditionally the preserve of field geologists. They usually mapped areas of outcropping deformed rocks and supplemented their work by laboratory studies of rock deformation and by theoretical work. Structural geology became tied to the geology of uplifts, folded belts, and underground mines, all of which were accessible to direct observation. Since World War II we have witnessed a tremendous development of geophysics in oceanography and in petroleum geology. Academic geophysicists in oceanography led their geological colleagues into modern plate tectonics and industry geophysicists developed reflection seismology into a superb structural mapping tool that penetrated the subsurface.
Today we are facing a situation where instruction and textbooks in structural geology are almost entirely dedicated to rock deformation, analytical techniques in detailed field geology and summaries of plate tectonics. Illustrations based on reflection seismic profiles are virtually absent in textbooks of structural geology. These texts illustrate only the parts of the proverbial elephant, together with some conjecture, but without ever offering a glimpse of the whole elephant.
Some of the reason cited for the relative scarcity of published reflection profiles are: 1) the confidentiality of exploration data; 2) difficulties in the photographic reduction and reproduction of seismic profiles for a book format; 3) the two-dimensional nature of vertical reflection profiles; and 4) the obvious distortions in reflection profiles that are typically recorded in time.
The AAPG leadership felt that it was time to attempt to correct the situation and to produce this picture and work atlas. The first volumes, of what may become a series of volumes, are addressing an audience that includes: petroleum geologists concerned with structural interpretations; exploration companies that provide in-house training; the AAPG continuing education program; and academic colleagues interested in updating their curricula in structural geology by inclusion of reflection profiles from the “real world” in their teaching.
The atlas is not meant to be a textbook in reflection seismology (instead we listed some at the end of this introduction) nor a text in structural and/or regional geology. Our intent is simply to provide a teaching tool.