Paleomagnetism of Silurian‐Ordovician sediments from the Valley and Ridge Province, northwest Georgia
The remanent magnetism (RM) for 93 specimens has been determined in 34 independently oriented samples from 20 sites at Ringgold Gap, Georgia, in the Valley and Ridge Province of the Southern Appalachians. Lithologies sampled include Middle Ordovician through Silurian fossiliferous limestones and hematitic sandstones and siltstones. The section is confined within a single thrust slice. Thermal demagnetization results indicate that hematite is the dominant RM carrier although detrital magnetite has also been identified optically in some specimens. Both normal and reversed polarities are present and the resulting paleopole is 28°N, 142°E (α95 = 7.3°). This pole falls within the cluster of published Lower Paleozoic Valley and Ridge poles but rather than clarifying the distribution of poles it augments the scatter. Three factors are thought to contribute to this scatter: (1) unresolved components of rotation, possibly introduced during folding and thrust faulting, which result in declination anomalies, (2) true vertical axis tectonic rotations during deformation, and (3) insufficient knowledge of the timing of magnetization. In light of these uncertainties, caution should be exercised in constructing a Lower Paleozoic apparent polar wander path with paleopoles from the Valley and Ridge Province. Copyright 1986 by the American Geophysical Union.
Publication Source (Journal or Book title)
Geophysical Research Letters
Morrison, J., & Ellwood, B. (1986). Paleomagnetism of Silurian‐Ordovician sediments from the Valley and Ridge Province, northwest Georgia. Geophysical Research Letters, 13 (3), 189-192. https://doi.org/10.1029/GL013i003p00189