Student Opportunities for Future Research
Kent C. Condie, Professor of Geochemistry
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1) A really exciting project is to evaluate geological evidence that might support a superplume event in the Early Ordovician and again near the end of the Permian. At both of these times, there is evidence for a rise in sea level and temporary cessation of reversals in the Earth's magnetic field, both of which are consistent with a superplume event. What else is preserved that may support superplume events? At least two Masters' theses are possible on this topic. |
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2) To better understand the tectonic setting of Proterozoic greenstones, there are opportunities for 2 or 3 Masters’ theses studying Proterozoic greenstones in New Mexico and Arizona, including the Tijeras greenstone near Albuquerque, which may represent part of an ophiolite sequence. These studies will involve careful mapping rocks units aimed at identifying the nature of the original rocks and geochemical studies of the basalts to constrain their tectonic settings. Picture on left: pillow basalts in the Tijeras greenstone near Albuquerque, NM. These may be ocean floor basalts formed some 1.7 billion years ago |
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3) Although it is well known that the Southwest North America grew by accretion of arcs in the Paleoproterozoic, the dip of the subduction zones along the southern margin of the Wyoming Archean craton is controversial. The Colberg Volcanics (picture on left shows pillow basalts from the Colberg Volcanics) in the Medicine Bow Mountains near Laramie, Wyoming, offer an opportunity to solve this problem in that they may be remnants of a continental margin arc built on the southern edge of the craton. Alternatively, these volcanics may represent rift-related volcanics, related perhaps to rifting of another continent from the edge of the Wyoming craton prior to Proterozoic arc accretion. In collaboration with scientists at the University of Wyoming, we will begin a detailed geochemical and U/Pb isotopic study to evaluate this question, which will provide at least one Masters' research project at New Mexico Tech. |
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4) To better understand the growth of continental crust in the southwestern United States, there is an opportunity for at least two graduate theses dealing with U/Pb dating and Hf isotopic studies of detrital zircons from Rio Grande and Colorado River sediments. Using a laser probe attached to an ICPMS, it is now possible to determine U/Pb isotopic ages and Hf isotopic compositions on the same zircon. From the results we can determine if the zircon comes from juvenile continental crust or from reworked crust, and thus this new analytical method provides a tracer to identify new crust and to track the growth rate of continents. (Picture on left shows detrital zircons from Western Australia, some of which are over 4.3 Ga.) |
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Last Updated: July 3, 2006 by Webmaster |