Abstract

The Cambrian Royer Dolomite in the Arbuckle Mountains, Oklahoma, contains an early Paleozoic magnetization and a nonpervasive, late Paleozoic remagnetization caused by meteoric fluids. The Royer was uplifted and underwent karst conditions, and eroded clasts were deposited in the Collings Ranch Conglomerate during the Pennsylvanian. An early Paleozoic, depositional or chemical remanent magnetization (Dec. = 109°, Inc. = 10°, tilt corrected) residing in magnetite is found in gray-brown, ferroan dolomite. A Pennsylvanian-Permian chemical remanent magnetization (CRM) residing in hematite (Dec. = 147°, Inc. = 4°, in situ) is associated with dedolomitized rocks in an alteration zone around and below the karst features. Clasts of the Royer in the Pennsylvanian Collings Ranch Conglomerate, correlated with the parent rock by petrographic, isotopic, and rock magnetic methods, also contain two magnetizations. The clast centers contain a predepositionai magnetization, whereas the clast margins contain a postdepositional CRM (Dec. = 152°, Inc. = 4°, in situ). Conglomerate tests using these magnetization components constrain the timing of remanence acquisition in the Royer Dolomite.

Field relations and the results of oxygen and carbon stable-isotope analyses indicate that the dedolomitization events were caused by near-surface, meteoric fluids that altered the Royer around the margin of the karst dissolution caves and the outer rims of Royer Dolomite clasts. Remagnetization was not pervasive, and an early Paleozoic magnetization is preserved in the dolomite below the zone affected by weathering.

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