The complex, polyphase structural, metamorphic, and magmatic history of the Alabama Tin Belt has been studied in order to yield unique solutions to the petrogenetic evolution of this region. The structural setting of the study area is interrelated with the metamorphic and igneous processes and provides temporal relationships between kinematic phases of deformation and the thermochemical aspects of orogenesis. / The metamorphic history of the study area is quantitatively characterized through mineral equilibria. The Wedowee, Hatchet Creek, and Higgins Ferry Groups' metamorphic rocks of the study area have experienced kyanite-sillimanite facies series regional metamorphism during the Acadian orogeny. A Barrovian geothermal gradient is defined in P-T space which is abruptly terminated by isothermal decompression associated with migmatization and S-type, Rockford Granite intrusion. The composition of the prograde metamorphic fluid is dominantly a H(,2)O-CO(,2)-CH(,4)-H(,2)S fluid phase. / The kinematic response to the polymetamorphic history of the area and later Alleghenian faulting in the Northern Alabama Piedmont involves at least three phases of foliation and four episodes of folding. The study area is subdivided into five structural domains in order to analzye the structures in each domain stereographically. This yields important information on the temporal, genetic, and geometric relationships between foliations, folds, and various lineations in the study area. / Geochemical characterization of the Rockford Granite indicates that it is a peraluminous, trondhjemite-granite suite. The trondhjemites are interpreted to be produced via Na-metasomatism where a pervasive, infiltrating, (delta)('18)O- and Na-rich metamorphic fluid alters an original granite. The predominant mineral reaction associated with the metasomatism involved a one-to-one, Na for K replacement in the feldspar and mica phases. The relatively unaltered Rockford Granite's granite is interpreted to be the result of 40% partial melting of a metasedimentary source. Differentiation within the granites involved restite-melt separation processes and minor fractionation. The Elkahatchee Quartz Diorite in the study area is characterized as a granodiorite-tonalite batholith. / Source: Dissertation Abstracts International, Volume: 47-05, Section: B, page: 1900. / Thesis (Ph.D.)--The Florida State University, 1986.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75824 |
| Contributors | DRUMMOND, MARK STEPHEN., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 509 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.002 seconds