Weathering effects on the magnetic properties of the Milledgeville granite, Georgia
One of the major problems in paleomagnetic sampling of granites in the southeastern United States is finding fresh outcrop. Since most outcrops are weathered to some extent, it is important to quantify the effect of weathering on the magnetic properties of individual samples. The Lake Sinclair dam site near Milledgeville, Georgia, was chosen for this study, where a very fresh, stable granite outcrops in the excavated spillway. Lying immediately above is the weathered equivalent. Drilled samples were obtained from fresh and weathered portions at one outcrop, and the remanent and induced magnetizations measured. With AF demagnetization, it was possible to obtain the stable remanent directions, exhibited by fresh samples, from all weathered samples. The induced and remanent magnetic behavior can be explained by maghemitization during weathering and the development of a secondary low oxidation magnetic phase and the reduction in domain size of primary magnetite. © 1981.
Publication Source (Journal or Book title)
Earth and Planetary Science Letters
Ellwood, B. (1981). Weathering effects on the magnetic properties of the Milledgeville granite, Georgia. Earth and Planetary Science Letters, 55 (2), 311-316. https://doi.org/10.1016/0012-821X(81)90110-2