Dr. Roberta L. Flemming

Mineralogy

Associate Professor
Ph.D. Queen's University, 1997
Office: BGS 0172
Phone: (519) 661-3143
Fax: (519) 661-3198
Email: rflemmin@uwo.ca

Research Interests

Professor Roberta Flemming and her research group study a variety of mineralogical and geological problems using a combination of crystallography, mineral chemistry and spectroscopy. Observations made from synthetic minerals produced at high temperatures and pressures in the laboratory, and from natural minerals found in Earth and planetary materials, are used to understand changes in mineral structure, chemistry, cation distribution, solid-solubility, and phase transition behaviour in response to changes in pressure, temperature, and composition (P-T-X), on Earth and other planetary bodies.

Flemming employs a variety of techniques, including X-ray diffraction and microdiffraction, Rietveld refinement of diffraction data, electron probe microanalysis (EPMA), and a variety of spectroscopic techniques, including solid-state nuclear magnetic resonance (NMR). Flemming’s current research objectives are outlined below:

Fundamental understanding and quantification of mineral behavior as a function of pressure (P), temperature (T) and composition (X) by synthesizing minerals at various P-T-X, and studying their crystal structure (X-ray diffraction/Rietveld refinement), crystal chemistry (EPMA), and cation order-disorder (NMR spectroscopy, e.g. ²⁹Si, ²⁷Al, , ¹⁷O).
Systematic mineralogical investigation of meteorites. In situ µXRD provides rapid mineral ID for meteorite classification and clues to thermal and shock history. In situ µXRD also provides shock stage quantification, as a function of strain related mosaicity (streaking or asterism along Debye rings). Rietveld refinement of powder XRD data provides modal mineral analysis, and enables crystal structural study of selected phases.
Systematic investigation of Kimberlite Indicator Minerals (KIM) (e.g. garnet, chromite, Cr-diopside). Variation in unit cell parameters (µXRD) is correlated to geochemical data (EPMA) with the aim of developing µXRD as a tool for diamond exploration. Inclusions and strain related mosaicity in minerals give additional clues to origin.
Development of micro X-ray diffraction (µXRD) as a tool for geologists. µXRD provides a unique opportunity to correlate crystal structural information with other microanalytical data on the microscopic scale (100-300 µm) not previously available. In situ examination of minerals preserves orientational information. Anticipated projects include development of µXRD-related exsolution geothermometry (e.g. two pyroxenes), and quantification of strain-related mosaicity in minerals in meteorites, impact structures, and tectonically deformed rocks, with the aim of developing a µXRD strain index.

Selected Publications

Izawa, M.R.M., Flemming, R.L., Banerjee, N.R. (2011) QUE 94204: A product of partial melting of an enstatite chondrite like protolith. Meteoritics & Planetary Science, 46: 1742–1753.

Vinet, N., Flemming, R.L. and Higgins, M.D. (2011) Crystal structure, mosaicity and strain analysis of Hawaiian olivines using in situ X-ray diffraction. American Mineralogist, 96: 486-497.

Izawa, M.R.M., Flemming, R.L., Banerjee, N.R. and McCausland, P.J.A. (2011) Micro X-ray diffraction (μXRD) assessment of shock stage in enstatite chondrites. Meteoritics and Planetary Science, 46: 638-651.

Izawa, M.R.M., Flemming, R.L., King, P.L., Peterson R.C., and McCausland, P.J.A. (2010) Mineralogical and spectroscopic investigation of the Tagish Lake carbonaceous chondrite by X-ray diffraction and infrared reflectance spectroscopy. Meteoritics & Planetary Science, 45: 675-698.

Izawa, M.R.M., Flemming, R.L. McCausland, P. J. A., Southam, G., Moser, D.E. and Barker, I.R. (2010) Multi-technique investigation reveals new mineral, chemical, and textural heterogeneity in the Tagish Lake C2 chondrite. Planetary and Space Science, 58: 1347-1364.

Lange, K., Rowe, R.K., Jamieson, H., Flemming, R., Lanzirotti, A. (2010) Characterization of geosynthetic clay liner bentonite using micro-analytical methods. Applied Geochemistry, 25: 1056-1069.

Izawa, M.R.M., King, P.L., Flemming, R.L., Peterson R.C., McCausland, P.J.A. (2010) Mineralogical and spectroscopic investigation of enstatite chondrites by X-ray diffraction and infrared reflectance spectroscopy. Journal of Geophysical Research – Planets, 115: (doi:10.1029/2009JE003452)

Smith, E., Helmstaedt, H.H. and Flemming, R.L. (2010) Survival of Brown Colour in Diamond During Storage in the Subcontinental Lithospheric Mantle. Canadian Mineralogist, 48: 571-582.

Izawa, M.R.M., Banerjee N.R., Flemming, R.L., Bridge, N.J. and Schultz, C. (2010) Basaltic glass as a habitat for microbial life: Implications for astrobiology and planetary exploration. Planetary and Space Science, 58: 583-591.

Izawa, M.R.M., Banerjee, N.R., Flemming, R.L. and Bridge, N.J. (2010) Preservation of microbial ichnofossils in basaltic glass by titanite mineralization. Canadian Mineralogist, 48: 1255-1265.

Moser, D.E., Davis, W.J., Reddy, S., Flemming, R.L. and Hart, R.J. (2009) Zircon U-Pb strain chronometry reveals deep impact-triggered flow. Earth and Planetary Science Letters, 277: 73-79.

Nene, S., Karhu, E., Flemming, R.L. and Hutter, J.L. (2009) A Diffusionless Transition in a Normal Alkane. Journal of Crystal Growth, 311: 4770–4777.

Flemming, R.L. (2007) Micro X-ray Diffraction (µXRD): A versatile technique for characterization of Earth and planetary materials. Canadian Journal of Earth Sciences, 44: 1333-1346.

Ning, G. and Flemming, R.L. (2005) Rietveld refinement of LaB₆: Data from µXRD. Journal of Applied Crystallography, 38, 757-759.

Flemming, R.L., Salzsauler, K., Sherriff, B.L. and Sidenko, N. (2005) Identification of scorodite in very fine-grained, high-sulfide arsenopyrite mine wastes using Micro X-ray diffraction (µXRD) Canadian Mineralogist, 43, 1527-1537.

Flemming, R.L. and Luth, R.W. (2002) ²⁹Si MAS NMR study of diopside - Ca-Tschermak clinopyroxenes: Detecting both tetrahedral and octahedral Al. American Mineralogist, 87, 25-36.

Courses Taught

Undergraduate courses (currently taught):
Earth Sciences 2206a: Mineral Systems, Crystallography and Optics
Earth Sciences 2212b: Genesis of Meteorites and Planetary Materials (even years)
Earth Sciences 3310b: Structure and Chemistry of Minerals and Materials (odd years)

Undergraduate courses (previously taught):
Environmental Science 300F: Great Lakes Pollution (2001, 2002)
Earth Sciences 3341b: Environmental Geochemistry (2003)

Graduate Courses:
Geology/Geophysics 9580a/9680a: Graduate Seminar (2005, 2007, 2008, 2009, 2010)
Geology 9516b: Advanced Mineralogy and Crystallography (2002, 2004, 2006, 2008, 2010, 2012)
Geology 9549a/b: Special Topics in Mineralogy (2005, 2012)

Students

Current:

Michael Craig Ph.D. NIR, NMR and XRD study of terrestrial impact glasses (with G. Osinski)

Matthew Izawa Ph.D. Mineralogical investigation of meteorites and terrestrial environments: mineralogical and biological evolution. (with N. Banerjee)

David Edey M.Sc. Micro-CT algorithms for reduction of high-density artifacts in meteorite scans. (with D. Holdsworth, Robarts)

Monika Haring M.Sc. Heating events in the early solar system: Clues from meteoritic pyroxene.

Jared Shivak M.Sc. Mineralogical evidence for habitability on Mars. (with N. Banerjee)

Former:

Michael Craig M.Sc. (2010) The effects of impact on the NIR spectra of carbonates and calibrations for use in planetary remote sensing.

Ben Harwood M.Sc. (2009) Crystal-chemical relationships in kimberlitic and non-kimberlitic garnet and ilmenite.

Matthew Izawa M.Sc. (2008) Mineralogy and IR spectroscopy of the Tagish Lake C2 chondrite and enstatite chondrites.

Jingshi Wu M.Sc. (2005) Cation ordering in diopside-jadeite solid solution.

Andrea Cade M.Sc. (2003) Colouration in lazurite from Baffin Island, Nunavut.

Available projects:

Available projects include:

Crystal structure, cation ordering and configurational entropy in pyroxene group minerals, using NMR spectroscopy and diffraction methods.
Systematic determination of unit cell parameters in KIM minerals (e.g. Cr-diopside and chromite) and investigation of crystal structural – crystal chemical correlations.
Mineralogical investigation of meteorites: Crystal chemical clues to formation, thermal and shock metamorphism, fusion crust formation aqueous processing, and weathering. Possible meteorites include chondrites (e.g. Allende), achondrites (e.g. 4 Vesta HEDs), martian, lunar.
Systematic determination of unit cell parameters for major minerals in meteorites (e.g. clinopyroxene and olivine) and correlation to mineral chemistry and planetary origin.
Quantification of strain-related mosaicity in minerals in meteorites, impact structures, and tectonically deformed rocks, with an aim toward development of a µXRD strain index, and calibration using existing strain indices.
Development of µXRD for exsolution geothermometry. (e.g. two pyroxenes). GADDS image provides simultaneous unit cell information for both phases, as well as their T-dependent orientational relationship.