Investigation of metasedimentary and metaigneous units of the northern Alabama Piedmont has revealed the following evidence: (1) stratigraphic continuity exists between previously uncorrelated lithotectonic blocks, (2) petrogenesis of synmetamorphic Rockford-type granite was controlled by the anatectic melting of metasedimentary units of greywacke composition producing S-type geochemical signatures, (3) estimates of pressure and temperature from metamorphic mineral assemblages yield Barrovian-type geothermal gradient terminated by a subsequent near-isothermal decompression event producing a clockwise P-T-time path in P-T space, and (4) estimates of the fluid composition in equilibrium with mineral assemblages of metasedimentary compositions indicate a metamorphic fluid composed of 0.90 H$\sb2$O, and 0.05 CO$\sb2$ and CH$\sb4,$ with the other fluid phases CO, COH, S$\sb2,$ O$\sb2,$ S$\sb8,$ H$\sb2$S being present in trace quantities. Metamorphic total fluid pressure was essentially equivalent to lithostatic pressure during peak metamorphic conditions (P$\sb{\rm T}$ = P$\sb{\rm F}).$ / Analysis of micro-, meso- and megascopic structural relationships has revealed 5 phases of deformation. Previous investigations have established the internal stratigraphy of structural blocks composing the northern Alabama Piedmont. This study identifies the conformable relationships between stratigraphy of the Coosa and Tallapoosa blocks. Because of thermal and structural correlation across the eastern-western Blue Ridge boundary (Hollins Line fault), the Ashland-Wedowee belt may have been proximal to the North American margin prior to the Acadian dynamothermal events. / Source: Dissertation Abstracts International, Volume: 53-09, Section: B, page: 4552. / Major Professor: James F. Tull. / Thesis (Ph.D.)--The Florida State University, 1992.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76734 |
| Contributors | Allison, David Theodore., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 401 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.0016 seconds