D. Sannemann, 1983. "Migration of Salt-Induced Structures", 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 deformation of sediments overlying a salt layer can result in the buildup of salt pillows, salt domes, and/or elongated salt walls. Depending on the event which triggers the deformation of the salt, different types of rim synclines on the flanks of the salt structures may occur. If the movement is purely halokinetic, the sedimentary cover over a saltpillow will be thinnest over the top, the thickening down the flanks resulting in a wedge-shaped primary rim syncline. in the piercing stage of the salt-dome a secondary rim syncline is formed with its thickest part toward the salt dome because of the salt withdrawal in the area surrounding the dome. If the salt movement is triggered by a tectonic event (e.g., by a displacement of the layers including the salt), usually no primary rim syncline is formed, since there is no salt pillow stage as the salt rises up along the faultplane.
In the Upper Permian Zechstein salt basin of northwest Germany the salt-induced deformation of the sediments is seen in a number of cases to start from a central "mother salt dome" and proceed outward in both directions. The seismic section shows one side of a salt dome "family," with the central salt dome at the righthand side of the profile. The rim synclines become progressively younger from right to left, showing an overlapping of the sediment wedges. The absence of a primary rim syncline points to a tectonic trigger for the generation of the "mother" salt dome.
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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.