Ph. D. Candidate
1459 Oxford Street
PO BOX 15000
Halifax NS B3H 4R2
Life Sciences Centre
4th floor, Ocean Wing
Dissolution of mantle minerals in kimberlite magmas and modeling of emplacement conditions of kimberlite magma.
The primary melt composition of kimberlites is largely uncertain, but it is widely agreed upon that kimberlite melts contain a high concentration of volatiles responsible for their explosive nature. Volatiles are believed to be composed of CO2 and H2O, but cannot be measured due to volatile loss during eruption. Resorption features such as etch pits and striations on recovered diamonds are believed to be the result of dissolution in the presence of volatiles and have been used to estimate the fluid composition by correlating these features to those produced in control experiments (Fedortchouk et al., 2007). Diamonds though are not very abundant in kimberlites and often not present at all whereas other mantle xenocrysts such as chromite and ilmenite occur in much higher abundance. But unlike diamonds, which are entirely of mantle-origin, multiple phases of chromite and ilmenite are usually present (Fig. 1a). A pilot study conducted at Dalhousie University has shown that resorptions features, similar to those observed on diamonds, are present on chromite and ilmenite macrocrysts (McIsaac, 2009: Fig. 1b) and are reproducible in controlled piston cylinder apparatus experiments.
The objective of the proposed project is to correlate observed resorption features on chromite and ilmenite to the fluid evolution of kimberlites during emplacement. A descriptive classification of resorption features will be developed from chromite and ilmenite grains recovered from select kimberlites. Piston cylinder apparatus experiments will be used to reproduce these features and derive the conditions (e.g., fluid composition, pressure, temperature, melt composition). Comparison of the resorption features to the chemical composition, reflective of oxides of different generations, of the grain will provide insight into how the fluid composition evolves during kimberlite emplacement. In addition to piston cylinder experiments, analytical methods to be used in this study include electron microprobe analysis, scanning electron microscopy, atomic force microscopy and possibly laser ablation- inductively coupled plasma – mass spectroscopy.
A combined compositional and dissolution study would contribute significantly as a potential diamond exploration tool. Chromite and ilmenite are commonly used kimberlite indicator minerals recovered in much higher abundance than diamonds during exploration. Since the preservation of diamonds is related to the fluid composition (Fedorthchouk et al., 2005), estimating the fluid composition by using resorption features on kimberlite indicator minerals, one may predict the diamond preservation within a kimberlite. This new method at looking at the crystallization history and fluid evolution in kimberlites will contribute to the understanding of kimberlite emplacement.
Figure 1: a) Compositional zoning within a chromite macrocryst from the Grizzly pipe indicate four phases (indicated by Roman numerals) of crystallization in this grain alone; b) example of chromite resorption feature (trigon protrusions) on the surface of a macrocryst from the Beartooth pipe (McIssac, 2009).
Fedortchouk, Y., Canil, D. & Carlson, J.A. (2005). Dissolution forms in Lac de Gras diamonds and their relationship to the temperature and redox state of kimberlite maga. Contributions to Mineralogy and Petrology, 150, 54-69.
Fedortchouk, Y., Canil, D. & Semenets, E. (2007). Mechanisms of diamond oxidation and their bearing on the fluid composition in kimberlite magmas. American Mineralogist, 92, 1200-1212.
McIssaac, E.M. (2009). Experimental Study of Surface Dissolution Features on Kimberlite Indicator Minerals (Unpublished B.Sc. Honours thesis). Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia. 99 pp.
- Ph. D. candidate, Dalhousie University, Halifax, NS
Thesis Title: Dissolution of mantle minerals in kimberlite magmas and modeling of emplacement conditions of kimberlite magma
Advisor: Yana Fedortchouk
- M. Sc. in Geology, University of Manitoba, Winnipeg, MB
Fall 2008 - Winter 2011
Thesis Title: The petrology, mineralogy and geochemistry of the Cinder Lake alkaline intrusive complex, eastern Manitoba
Thesis Advisor: Anton Chakhmouradian
- B. Sc. in Physical Geography Honours (First Class Honours)
2008, University of Manitoba, Winnipeg, MB
Thesis Title: CO2 gas exchange between the atmosphere and the ocean in the Arctic during the 2006 fall Amundsen cruise
Thesis Advisor: Tim Papakyriakou
Kressall, R.D., Chakhmouradian, A.R. and Böhm, C.O. (2010): Petrological and geochemical investigation of the Cinder Lake intrusive alkaline complex, Knee Lake area, east-central Manitoba (part of NTS 53L15).in Report of Activities 2010, Manitoba Innovation, Energy and Mines, Manitoba Geological Survey, p.146-158.
Chakhmouradian, A.R., Böhm, C.O. Kressall, R.D. and Lenton, P.G. (2008). Evaluation of the age, extent and composition of the Cinder Lake alkaline intrusive complex, Knee Lake area, Manitoba (part of NTS 53L15). Rep. Activities, Manitoba Sci. Techn., Energy and Mines, Manitoba Geological Survey, 109-120.
McLeish, D.F., Kressall, R.D., Johnson, S., Chakhmouradian, A.R., Crozier, J. and Mortensen, J.K. (2010) : The Aley carbonatite complex: The structural evolution, petrogenesis and tectonic implications of a Cordilleran niobium deposit. Poster, presented at Association for Mineral Exploration British Columbia Roundup, January 24-27, 2011, Vancouver, BC.
Kressall, R.D., Chakhmouradian, A.R. and Böhm, C.O. (2010): Evidence for carbonatite magmatism at Cinder Lake, east-central Manitoba: Implications for rare-earth mineralization. Poster, presented at Manitoba Mining and Minerals Convention, 18-20 November, 2010, Winnipeg, MB.
Kressall, R.D., Chakhmouradian, A.R., McLeish, D.F., Crozier, J. (2010) : The Aley carbonatite complex - Part I: The petrogenesis of a Cordilleran niobium deposit. Oral presentation, presented at the International Workshop: Geology of Rare Metals, 9-10 November, 2010, Victoria, BC.
McLeish, D.F., Kressall, R.D., Chakhmouradian, A.R., Crozier, J., Johnson, S. and Mortensen, J.K. (2010) The Aley carbonatite complex - Part II: Structural evolution of a Cordilleran niobium deposit. Oral presentation, presented at the International Workshop: Geology of Rare Metals, 9-10 November, 2010, Victoria, BC.
Chakhmouradian, A.R., Böhm C.O., Mumin, A.H., Coëslan, C.G., Demény, A., Reguir,E.P., Simonetti, A., Creaser, R.A., Kamenov, G.D., Kressall, R.D. and Lepekhina, E.N. (2010). Manitoba: a "hotspot" of carbonatitic magmatism in the Precambrian. Oral presentation, presented at The 20th General Meeting of the International Mineralogical Association, 21-27 August 2010, Budapest, Hungary. (Abstract published in Acta Mineralogica - Petrographica, vol. 6, p. 551)
Kressall, R. D., Chakhmouradian, A.R., Böhm, C.O., Yun, M. and Yang, P. (2009). Trace-element geochemistry of the Cinder Lake alkaline intrusive complex: Insights into the distribution of carbonatites. Poster, presented at Manitoba Mining and Minerals Convention, 19-21 November, 2009 Winnipeg, MB.
Chakhmouradian A.R., Böhm C.O., Kressall R.D. and Lenton P.G. J.K. (2009). The Cinder Lake instrusive alkaline complex, Knee Lake area, central Manitoba: a syenite-carbonatite association from a Neoarchean continental margin. Poster, Presented at Joint Assembly 2009, Toronto, ON. (Abstract available at http://www.gac.ca/activities/abstracts/2009_Join_Assembly/html/V31B-01.html)
Else, B.,Papakyriakou, T., Kressall, R. and Yackel, J. (2006). Bulk Aerodynamic Estimates of Carbon Dioxide Flux in Hudson Bay. Poster, Presented at ArcticNet Annual Science Meeting, Victoria, BC, CA.(Abstract available at http://www.arcticnet.ulaval.ca/pdf/programme_ ASM2006.pdf; p.51)
- 2012 Clayton H. Riddell Faculty of Environment, Earth and Resources Masters Thesis Prize
- 2011 Dalhousie University President's Award
- 2011 NSERC Postgraduate Scholarship
- 2011 C.K. Bell Memorial Research Prize
- 2009 Rita Wadien Memorial Scholarship
- 2008 Program Medal - Highest Standing in Clayton H. Riddell Faculty of Environment, Earth, and Resources Honours Degree Program
- 2008 University of Manitoba Graduate Fellowship
- 2008 NSERC Alexander Graham Bell Canada Graduate Scholarship
- 2008 NSERC Undergraduate Summer Research Award
- 2007 UMSU Scholarship
- 2007 Roscoe R. Miller Scholarship
- 2007 NSERC Undergraduate Summer Research Award
- 2006 Dr. A. W. Hogg Undergraduate Scholarship
- 2006 Isbister Scholarship in Environment
- 2006 UMSU Scholarship
- 2006 Joseph Wolinksy Scholarship
- 2006 NSERC Undergraduate Summer Research Award