HR: 1340h
AN: U33A-0033    [Abstracts]
TI: Remagnetized Paleopoles: Problems and Applications
AU: * Elmore, R D
EM: delmore@ou.edu
AF: School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd St., Norman, OK 73019 United States
AB: Since remagnetized poles were first suspected by Creer and his coworkers in the 1960s, paleomagnetists have made considerable advances in our knowledge of how rocks become remagnetized. Creer published the "remagnetization hypothesis" in 1968, proposing that the formation of secondary iron oxides in red beds as a result of tropical weathering can explain why some paleopoles from early Paleozoic units in North American and Europe were acquired in the late Paleozoic. Subsequent studies have demonstrated that remagnetization is widespread and can be caused by many diagenetic processes such as weathering fluids, basinal/mineralizing fluids, orogenic fluids, hydrocarbons, burial diagenetic processes (e.g., clay diagenesis and maturation of organic matter), as well as other processes. Several geologic controversies such as the origin of magnetization in red beds, the Laurentia/Northern Appalachians megashear hypothesis, and the Cambrian loop hypothesis have also emphasized the importance of recognizing remagnetization. Although some of these geologic hypotheses have been shown to be incorrect because of remagnetization, they were ultimately very useful because they drove research and led to a much better understanding of how rocks become remagnetized. Whereas remagnetization may complicate the interpretation of depositional magnetizations, we now understand that secondary magnetizations can be tangible evidence of chemical and/or thermal events in the diagenetic history of a rock. Paleopoles for such magnetizations, when combined with other information, can provide valuable information on the nature and timing of diagenetic events. Although considerable progress has been made in understanding remagnetization, more work is needed to test different mechanisms and several major issues (e.g., origin of synfolding magnetizations) remain to be completely resolved.
DE: 1527 Paleomagnetism applied to geologic processes
DE: 1533 Remagnetization
SC: Union [U]
MN: 2004 AGU Fall Meeting