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You searched for +publisher:"Dalhousie University" +contributor:("D. Barrie Clarke"). One record found.

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Dalhousie University

1. Hilchie, Luke Jonathan. Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas.

Degree: MS, Department of Earth Sciences, 2011, Dalhousie University

This thesis includes an Electronic Appendix, available at http://dalspace.library.dal.ca

Volatiles are fundamental to many aspects of kimberlite magmatism. However, the volatile compositions and concentrations are poorly defined. Enrichment of H in kimberlitic olivines, many of which are xenocrysts, suggests high water content, but the extent to which H exchanges between these xenocrysts and kimberlite magmas remains unclear. This study investigates zonation of H in kimberlite-hosted xenolith and macrocrystic olivines using Fourier transform infrared spectroscopy to constrain the extent of re-equilibration. Data show that, depending on locality, xenolith olivines exhibit either no H-zonation, or substantial H-depletion in their rims. Macrocrysts feature similar trends to xenolith olivines from the same intrusion. In terms of the rim:core ratio of H, strongly zoned olivines average ~0.5, whereas poorly zoned olivines average at ~0.9 (macrocrysts) or 1.0 (xenolith olivines). Locality-specific H-zonation could result from different magmatic thermal regimes, water concentrations, or ascent durations. If the magmas that contained weakly zoned olivines were anhydrous, their restricted zoning requires ascent durations (< 20 min at 1100 °C) that are considerably shorter than published estimates (~1-24 hr at 1100 °C). These findings suggest that elevated magmatic water concentrations minimized loss of H from olivine in these kimberlites, showing that non-equilibrated xenocrysts could indirectly record high water concentrations in the form of weak H-zonation. Strong H-depletion patterns in olivines from other kimberlites may reflect lower initial magmatic water concentrations, or loss of fluid to country rocks. Future studies could compare H-zonation to temperature and ascent rate estimates, and field relationships to better elucidate the causes of locality-specific H-zonation. An apparent correlation between diamond grade and H-zonation warrants further investigation.

Advisors/Committee Members: Cliff Shaw (external-examiner), Nicholas Culshaw (graduate-coordinator), D. Barrie Clarke (thesis-reader), Alan Anderson (thesis-reader), Yana Fedortchouk (thesis-supervisor), Not Applicable (ethics-approval), Not Applicable (manuscripts), Not Applicable (copyright-release).

Subjects/Keywords: Kimberlite; olivine; hydrogen; water; diffusion; zonation; mantle; peridotite; xenocryst

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hilchie, L. J. (2011). Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas. (Masters Thesis). Dalhousie University. Retrieved from http://hdl.handle.net/10222/14103

Chicago Manual of Style (16th Edition):

Hilchie, Luke Jonathan. “Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas.” 2011. Masters Thesis, Dalhousie University. Accessed April 25, 2019. http://hdl.handle.net/10222/14103.

MLA Handbook (7th Edition):

Hilchie, Luke Jonathan. “Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas.” 2011. Web. 25 Apr 2019.

Vancouver:

Hilchie LJ. Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas. [Internet] [Masters thesis]. Dalhousie University; 2011. [cited 2019 Apr 25]. Available from: http://hdl.handle.net/10222/14103.

Council of Science Editors:

Hilchie LJ. Zonation of Hydrogen in Kimberlitic and Mantle Olivines: A Possible Proxy for the Water Content of Kimberlite Magmas. [Masters Thesis]. Dalhousie University; 2011. Available from: http://hdl.handle.net/10222/14103

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