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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 54 (1970)

Issue: 3. (March)

First Page: 561

Last Page: 562

Title: Previous HitMagneticNext Hit Grain Fabric of Sedimentary Rocks: ABSTRACT

Author(s): H. Ab Iorwerth

Article Type: Meeting abstract


It is well known that measurement of Previous HitmagneticNext Hit anisotropy indicates the dimensional grain fabric of natural rocks. Although the directional results are easily interpreted, the quantitative descriptive parameters of the Previous HitmagneticNext Hit fabric require more care--but they can give valuable information as to the nature of the grain fabric. In direct grain-shape-related Previous HitmagneticNext Hit anisotropy, e.g., in magnetite, it is possible to compare Previous HitmagneticNext Hit and optical fabric results by using a density function to describe the distribution of the dimensional axes of an aggregate of similar particles. The data are tested with sand deposited at the angle of repose. By using this method to produce a standard depositional

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mechanism, it is seen that the Previous HitmagneticNext Hit fabric resulting from magneto-crystalline anisotropy within particles such as hematite has similar directional properties, but the descriptive parameters differ from the magnetite example. In natural sedimentary rocks the source mineral grains causing the Previous HitmagneticTop fabric are more elusive. Nevertheless, simple deposition tests with crushed samples confirm that the directional data are correct. Also the descriptive parameters can be used to distinguish between primary and various deformational fabrics.

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