T.D. Crutcher, 1983. "Southeast Georgia Embayment", 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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This seismic section is located on the Atlantic continental shelf about 60 mi (96.5 km) from the Georgia coast. The line crosses a half-graben containing steeply-dipping rocks sub-cropping at, and truncated by, a regional unconformity. The half-graben probably formed during the early Mesozoic rifting cycle which preceded the separation of the North America and Africa plates. The oldest rocks overlying the unconformity at this location are early Early Cretaceous in age. The dipping section beneath the unconformity is inferred to be composed of Triassic or Paleozoic clastics. Onshore wells in northern Florida and southern Georgia have drilled unmetamorphosed lower Paleozoic sandstone and shale beneath the lower Mesozoic Unconformity. These sediments have a greater lithologic and paleontologic similarity to lower Paleozoic rocks in Senegal, West Africa, than to the age-equivalent section on the west side of the Appalachians. Most pre-drift restorations of Africa and North America show Senegal and the southeastern United States more or less in juxtaposition.
Lippert, R.H., 1983, The "Great Stone Dome" - a compaction structure, in A.W. Bally, ed., Seismic expressions of structural styles, vol. 1: AAPG Studies in Geology Series No. 15, v. 1, p. 1.3-1 - 1.3-4.
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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.