This study focuses on exocontact mineral assemblages to determine composition, thermal signatures, and the extent of exomorphism that occurred between the Mt. Mica pegmatite and the migmatite host rock at the contact. Biotite-garnet thermometry of country rock samples resulted in an average temperature estimate of 630 °C. Measured biotite Fe/(Fe+Mg) ratios were used to calculate an fO2 of -18. The results indicate that the country rock and pegmatite formed under similar oxidizing conditions near the quartz-fayalite-magnetite (QFM) equilibria buffer. Whole rock (REE) analysis indicates an interaction trend between the country rock and pegmatite. Exomorphism does not appear to have been significant at Mt. Mica, likely due to the moderately evolved nature of the pegmatite. Minor B leakage into the surrounding country rock is constrained to within 15 cm from the contact. Results indicate no enrichment of alkali elements (Li, Rb, Cs), As, U, or F occurred in minerals analyzed.
| Identifer | oai:union.ndltd.org:uno.edu/oai:scholarworks.uno.edu:td-2856 |
| Date | 16 May 2014 |
| Creators | Clark, Kimberly T |
| Publisher | ScholarWorks@UNO |
| Source Sets | University of New Orleans |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of New Orleans Theses and Dissertations |
Page generated in 0.0024 seconds