Application to Stratigraphy and Diagenesis
Published:January 01, 1993
Paleomagnetic, petrographic, and geochemical results, as well as field relationships, are used to relate Late Paleozoic chemical remanent magnetizations (CRMs) to the migration of basinal fluids in Ordovician carbonates in the Arbuckle Mountains, southern Oklahoma. The Viola Limestone contains a pervasive Pennsylvanian synfolding CRM residing in magnetite and a localized Permian CRM which resides in hematite and occurs in alteration zones around veins mineralized with calcite and Mississippi-Valley-type oxides and sulfides. The vein mineralization precipitated from basinal fluids that were warm, saline, and radiogenic. Radiogenic 87Sr/86Sr ratios of the limestones in the alteration zones and the fact that there is more significant alteration closer to the veins suggest that the basinal fluids were also responsible for alteration in the limestones. The coincidence of the geochemical and remagnetization trends suggest that the Permian CRM dates the migration of the basinal fluids in the veins. Geochemical results from the Viola with pervasive CRM indicate that it is relatively unaltered, with no evidence for radiogenic basinal fluids. This suggests that a mechanism that does not necessarily require exotic externally-derived fluids is needed to explain the origin of the pervasive CRM.
Liesegang-banded carbonate around calcite-filled fractures in the Kindblade Formation also contains a Permian CRM residing in hematite. The fluid that precipitated the hematite liesegang bands emanated from the fractures and, based on geochemical results, was basinal in origin.
The results of this study suggest that basinal fluids migrated through the carbonates in the Arbuckle Mountains during the Permian, although perhaps in several episodes. The flow of basinal fluids was focused in veins and only locally altered the host carbonates.
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Applications of Paleomagnetism to Sedimentary Geology
Applications of Paleomagnetism to Sedimentary Geology - Based on the 1991 SEPM Research Symposium, the results are directed towards bringing the disciplines of Paleomagnetism and sedimentary geology closer together. Advances in the field of sedimentary geology will likely result from continued development of new ideas, questioning of old dogma, and, most importantly, providing means for testing these new hypotheses. It is hoped that the union of these two disciplines will help address many fundamental geological questions, such as the perennial problems of precise age-dating, stratigraphic correlation and geometries, understanding the timing and nature of post-depositional diagenetic fabrics, and the intriguing relationship between hydrocarbons and magnetization. The reader will find an unusual diversity of research topics presented in this volume. This diversity serves as a testimony to the potential applications awaiting the sedimentary geologist willing to explore these new paleomagnetic tools.