Mylonite zones associated with thrust faults, Madison County, North Carolina / by Keith R. Masil.
| Author/creator | Marsil, Keith R. author. |
| Other author | Lawrence, David P., 1943- degree supervisor. |
| Other author | East Carolina University. Department of Geology. |
| Format | Theses and dissertations |
| Production | 1992. |
| Description | 91 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | The Meadow Fork and Rector Branch thrust faults are subparallel northeast-trending, southeast-dipping zones of ductile deformation bordering the southern margin of the Hot Springs Window in the North Carolina Blue Ridge. The faults are characterized by subzones of protomylonites and mylonites. Mylonite protoliths are regionally metamorphosed greenschist-grade granite and granodiorite gneiss. Grain size reduction begins at fault zone margins and continues through zones of increasing deformational intensity. Grain size reduction processes included ductile deformation in quartz, ductile/brittle deformation in feldspars, and chemical alteration in the feldspars and micas. Sense of shear was determined with microstructural criteria (sigma and theta porphyroclast systems; shear bands; subgrain fabrics in quartz ribbons; fractured and displaced feldspar grains). Fluid-chemical processes contributed to microstructural development and to changes in chemical composition as evidenced through XRF spectrometry. Microstructural criteria record thrust motion (upper plate moved NW) along both faults and localized post-thrust backslip (normal fault motion) along the Rector Branch fault. Textural evidence ( e.g. symmetrical and asymmetrical porphyroclast systems) suggests that the mylonites are the products of heterogeneous deformation. The microstructural behavior of quartz and feldspar and the metamorphic mineral assemblages suggest that deformation temperatures were near 450 degrees Celsius. |
| General note | Submitted to the faculty of the Department of Geology. |
| General note | Advisor: David P. Lawrence |
| Dissertation note | M.S. East Carolina University 1992 |
| Bibliography note | Includes bibliographical references (leaves 86-91). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |
Availability
| Library | Location | Call Number | Status | Item Actions |
|---|---|---|---|---|
| Joyner | University Archives | ASK AT SPECIAL COLLECTIONS DESK | ✔ Available | Request Material |
| Electronic Resources | Access Content Online | ✔ Available |