Structure and petrology of the Fountain Quarry Granite / Michael T. Christopher.
| Author/creator | Christopher, Michael T. author. |
| Other author | Mauger, Richard L. (Richard Leroy), 1936- degree supervisor. |
| Other author | East Carolina University. Department of Geology. |
| Format | Theses and dissertations |
| Production | 1979. |
| Description | vi, 74 leaves, 5 unnumbered leaves of plates : illustrations, maps (4 folded in pocket) ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | The Fountain Quarry Granite is a small, elongate pluton unconformably overlain by Pleistocene sediments at Fountain, on the coastal plain of North Carolina. Petrologic analysis of the rock indicates that it is a fine- to medium-grained peralkaline granite containing riebeckite, aegirine, orthoclase, and nearly pure albite. Chemical analyses of the granite show that it is comparable to other peralkaline granites worldwide. The rock contains a large, fine-grained aplite vein and several small, poorly-developed pegmatites, which occur as riebeckite-bearing quartz veins. The pegmatites also contain small amounts of fluorite, ilmenite, sphalerite, and molybdenite. Structural features in the granite include a prominent flow foliation defined by mafic minerals and wallrock xenoliths, and well-developed sets of cross joints and longitudinal joints. The two joint sets are roughly perpendicular, and the average strike of the longitudinal joints is parallel to the north-south axis of the pluton. The pluton contains no major faults, although small movements have occurred along joint planes in response to regional tectonism. However, the rock does not appear to have been regionally metamorphosed. A preliminary Rb-Sr whole-rock age date suggests a late Paleozoic origin 87 86 for the granite. The high initial Sr /Sr ratio (about 0.730) indicates that the partial melting of crustal rocks may have been involved. Peralkaline magmas are characteristically associated with zones of crustal rifting. The preliminary age date calculated for the Fountain Quarry Granite does not coincide veil with known periods of rifting along the eastern margin of North America. This suggests that either the rock is older than late Paleozoic, or that zones of tensional tectonics remained near the edge of the continent prior to the collision with Africa about 280 m.y. ago. |
| Local note | Joyner-"Submitted to the graduate faculty of the Department of Geology ... in partial fulfillment of the requirements for the degree Master of Science in Geology." |
| General note | Submitted to the Graduate faculty of the Department of Geology |
| General note | Advisor: Richard L. Mauger |
| Dissertation note | M.S. East Carolina University |
| Bibliography note | Includes bibliographical references (leaves 71-74). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |