The field of petrology explores the formation, composition, and structure of rocks on a microscopic scale.
Linda Kah's research focuses on integrating sedimentology, stratigraphy, geochemistry, and paleobiology in understanding the evolution of the Earth's biosphere. Ongoing research includes the following projects:
Understanding Unusual Carbonate Fabrics
Molar-tooth structure (MT) is an enigmatic Precambrian carbonate fabric characterized by variously shaped voids filled with a characteristically uniform, equant microspar. A combination of petrographic analysis (via transmitted light, SEM, and cathodoluminescence microscopy), mineralogical analysis (via raman spectroscopy), 3-dimensional structural analysis, geochemical analysis, and laboratory experiments has helped us better understand both the formation of this unusual microfabric, and its implications for the chemical evolution of the Proterozoic carbonate system. Other research focused on a related fabric, termed herringbone carbonate (HB), which consists of unusual carbonate cements whose c-axis shifts direction along the length of the crystal.
Cathodoluminescence image of MT microspar, showing discrete non-luminescent crystals with isopachous, luminescent rims
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In as much as the Earth is a planet, a significant portion of Larry Taylor's studies address its early evolution, particularly the mantle and interaction with its derivative, the crust. All of our studies of the Earth are guided by a single goal, to understand the origin and evolution of the Earth's mantle and derivative melts. These studies are focused upon the chemical and mineralogical nature of the Earth's mantle, funded by the NSF. The rocks involved are mainly from kimberlites, the source rock for diamonds formed deep (150-200 km) within the Earth, but also xenoliths from alkali basalts, world-wide. Studies of these mantle samples, including the diamonds and their inclusions, have centered around eclogite xenoliths in kimberlites from several locales, notably southern Africa and Yakutia, Siberia. The results on these studies are extremely intriguing - subducted oceanic crustal protoliths for diamondiferous eclogites underlying the Kaapvaal and Siberian cratons. These are highly significant studies which bear directly upon the formation of the Earth's crust, continental cores, and plate tectonics.
Combined EMP, SIMS, LA-ICP-MS, and isotopic studies have already come up with fantastic discoveries. This intensive mode of extracting the most science from a given sample is a carry over from Taylor's method of 'attacking' lunar materials. After all, these diamondiferous samples are extremely rare and unique, quite like lunar rocks.