Crustal xenolith magnetic properties and long wavelength anomaly source requirements

Geophysical Research Letters - Tập 9 Số 4 - Trang 329-332 - 1982
P. J. Wasilewski1, M. A. Mayhew2
1 NASA, Goddard Space Flight Center Laboratory for Extraterrestrial Physics, Greenbelt, Md., United States
2Business and Technological Systems, Inc. Seabrook, MD, United States

Tóm tắt

Granulite xenoliths, probable components of the lower continental crust, are a primary source of information about the magnetization of the lower crust. Magnetization values for lower crustal xenoliths from three tectonic settings (converging plate margin, rift valley, and continental intraplate region) demonstrate that metabasic rocks in the granulite facies have magnetization values consistent with magnetizations inferred for modeled sources of long wavelength anomalies. Measured Curie points for granulite xenoliths are near 560‐570°C except for those from rift zones and other regions where anhydrous, probably reducing lower crustal conditions exist in a steep geothermal gradient. In samples from the reducing environments Curie points <300°C are measured. The lower crust could be the most magnetic crustal layer. Satellite magnetic anomalies may serve to delineate magnetization provinces which may be related to the tectonic and chemical evolution of continents.

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Tài liệu tham khảo

10.1016/0012-821X(69)90003-X

10.1016/0016-7142(76)90005-3

10.1139/e77-150

10.5636/jgg.31.545

Dunlop D. J., 1974, Thermal enhancement of magnetic susceptibility, J. Geophys., 40, 4339

10.1080/11035897609454379

10.1111/j.1365-2478.1976.tb00926.x

Hall D. H., 1974, Long‐wavelength aeromagnetic anomalies and deep crustal magnetization in Manitoba and north‐western Ontario, Canada, J. Geoph., 40, 403

10.1139/e79-162

10.1029/RG019i002p00271

10.1139/e77-239

Krutikhovskaya Z. A., 1979, Longwavelength magnetic anomalies as a source of information about deep crustals structure, J. Geoph., 46, 301

10.1139/e79-087

Mayhew M. A., Application of satellite magnetic anomaly data to Curie isotherm mapping, J. Geoph. Res.

Mayhew M. A., An equivalent layer magnetization model for the United States derived from satellite altitude magnetic anomalies, J. Geoph. Res.

Mayhew M. A., An equivalent layer magnetization model for the United States derived from Magsat data, Geoph. Res. Lett

Mayhew M. A., in press, Satellite and surface geophysical expression of anomalous crustal structure in Kentucky and Tennessee, Earth Plan Sci. Lett

10.1029/JB077i035p07022

Padovani E. R., 1979, The Earth's Crust. Amer. Geoph. Union Mon., 19

10.1139/e72-018

10.1038/256015a0

10.5636/jgg.11.125

10.1130/0091-7613(1973)1<107:AATTBT>2.0.CO;2

10.1007/BF02597385

10.1029/GL006i007p00541

Wasilewski P. J. E. R.Padovani Crustal magnetization beneath the southern Rio Grande Rift based on xenoliths from Kilbourne Hole and Pti M A stra ts)Conference on Processes of Planetary Rift 153–155 1981.

Wasilewksi P. J., The Ivrea Zone as a model for the distribution of magnetization in the continental crust

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Geophysical Research Letters

Tập 9 Số 4

329-332

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