The Amba Dongar carbonatite complex, India is host to a large fluorite deposit. The complex consists of a small ring structure comprised of early carbonatite breccia, a large, outer lining of calcitite and a number of small ankeritic carbonatite plugs. Surrounding the carbonatite ring are numerous plugs of nephelinitic and phonolitic syenites. The complex was intruded into Late Cretaceous Bagh Sandstones and Late to Early Paleocene Deccan Volcanics. / The hydrothermal history of the complex is extensive, consisting of two main systems, the first resulted in large amounts of fenitization, causing extensive K and Na metasomatism of the surrounding sandstones and the second, dealt with here, was responsible for the silicification of large amounts of the calcitite and the deposition of economic quantities of fluorite. / The deposit consists of veins and vug fillings of blue, purple, white, yellow and colorless fluorite. The main ore zone, which is currently under production, and most other showings, are found near the carbonatite-sandstone contact. / Chemical analyses and mass balance calculations show that the fluids responsible for silicification removed significant quantities of Ca from the rock while adding large amounts of Si, Al and F. Alteration associated with fluorite deposition involved the removal of Al from the rock and the addition of large quantities of F and Si. / Fluid inclusions in fluorite point to a low temperature-low salinity ore fluid, which decreased in temperature and salinity with evolution. Crushing experiments performed on fluid inclusions in both fluorite and quartz reveal the presence of ${ approx0.08}$ m of dissolved CO$ sb2$ in solution while analyses of leachates and decrepitate residues from fluid inclusions show significant concentrations of Ca, Al, Na, Cl and S in their fluids. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68237 |
| Date | January 1993 |
| Creators | Palmer, David A. S. |
| Contributors | Williams-Jones, A. E. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Earth and Planetary Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001394265, proquestno: AAIMM94495, Theses scanned by UMI/ProQuest. |
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