The Department of Geosciences at Western Michigan University sponsors a seminar series, student proposal sessions, and thesis and dissertation defenses. Please check back in the fall for a detailed schedule of all we will have to offer!
Fall 2015 seminar series
Monday, Oct. 19, 2015, from 4-5 p.m. in 1118 Rood Hall
New Insights Into the Stratigraphic Framework of the Middle-Upper Devonian Transition in the Michigan Basin
High-resolution stratigraphic correlation of Middle and Upper Devonian strata in the Michigan Basin is hindered by a lack of extensive outcrops, complex lithofacies changes across the basin, and limited previous work on conodont and brachiopod biostratigraphy. We present new litho-, bio-, sequence- and chemostratigraphic data from both core and outcrop (including many type-sections) from throughout the basin, and our resulting working-model chronostratigraphic framework. Stratigraphic units included in this study are the constituent formations of the upper Traverse Group in Michigan, the Thiensville and Milwaukee Formations of Wisconsin, and the overlying Antrim Shale Formation which is found throughout the extent of the basin.
Dr. Jay Zambito
Assistant Professor, University of Wisconsin-Extension
Geologist, Wisconsin Geological and Natural History Survey
Monday, Oct. 26, 2015, from 4-5 p.m. in 1118 Rood Hall
Martian soil occurrence in some meteorites coming from Mars
Among several meteorites found on Earth, there are some meteorites that come from Mars which are known as “SNC” or Martian meteorites. Using a variety of experimental techniques, planetary scientists have established that they indeed originate from the surface of Mars. Some of these Martian meteorites contain impact melt (IM) glasses produced as result of shock heating by the meteoroid impact on Mars that launched these objects into space. On mass-spectrometric analysis they yield noble gases whose elemental and isotopic composition is very similar to that of Martian atmosphere, thereby providing unequivocal evidence for their Martian origin. Some of these IM glasses contain large excesses of sulfur (occurring as sulfides, sulfites and sulfates mixed in different proportions) compared to the host meteorite in which they are embedded. Sulfur is known to be ubiquitously occurring on Mars surface based on Curiosity, Spirit and Opportunity rover-measurements. In general, it is considered as a characteristic signature of Martian soil. The analytical studies of these IM glasses by the state of art advanced experimental techniques using S- K XANES, EPMA, Nano-SIMS, FE-SEM, TIMS and Noble gas mass spectrometric methods in our labs show several diagnostic features that are consistent with Martian soil characteristics. These results provide strong evidence for the incorporations of Martian soil constituents into the glass-precursors prior to the impact on Mars surface. Some of the IM glasses (though their availability is very small in quantity, i.e., in milligrams) could serve as potential source of Martian soil for terrestrial laboratory studies at present till the Mars- Sample- Return- Mission brings the Mars samples back to Earth in future. Some recent developments in this area will be presented.
Dr. M.N. Rao
Senior scientist, Johnson Space Center