Origin of chert in the middle Ordovician Lincolnshire limestone, Tazewell County, Virginia / by Sarah M. Rice.
| Author/creator | Rice, Sarah M. author. |
| Other author | Neal, Donald W., degree supervisor. |
| Other author | East Carolina University. Department of Geology. |
| Format | Theses and dissertations |
| Production | 2005. |
| Description | x, 68 leaves : illustrations (some color), color maps ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Subject | The Middle Ordovician Lincolnshire Limestone in Tazewell County, Virginia, contains nodular chert interbedded with limestone. From Pisgah, Virginia, in the east to Pounding Mill, Virginia, in the west along US 460, the lithology of the Lincolnshire Limestone varies from siliceous mudstone to cherty wackestones to sparsely cherty dolomitic packstone. These lithologies were deposited in environments ranging from basin through outer shelf to inner shelf Observations of chert nodules and the surrounding limestone indicate that the nodules formed by a diagenetic replacive process. There is no unequivocal evidence of the source of the silica. Possible sources include biogenic (sponge spicules), volcanogenic (beta-quartz crystals), terrigenous (quartz grains and clay minerals), and silica-rich meteoric water. A variety of post-silicification diagenetic features were observed. They include silica-filled pores, late-stage dolomitization, solution seams and stylolites, and open and healed fractures. A model is proposed where post-depositional tectonism results in uplift and subsequent dolomitization in a mixing-zone envitonment. The dolomitization was interrupted by silicification and nodule formation. Later dolomitization, fracturing and compaction modified the unit. |
| General note | Presented to the faculty of the Department of Geology. |
| General note | Advisor: Donald W. Neal |
| Dissertation note | M.S. East Carolina University 2005 |
| Bibliography note | Includes bibliographical references (leaves 54-56). |
| 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 |