Black Coating on Dolomite in Missouri: Organics or lnorganics Containing Manganese Oxide?
Department
Geosciences and Geological and Petroleum Engineering
Major
Geology and Geophysics
Research Advisor
Wronkiewicz, David J.
Advisor's Department
Geosciences and Geological and Petroleum Engineering
Funding Source
Missouri S& T Opportunities for Undergraduate Research Experiences (OURE) Program
Abstract
Dolomite CaMg(CO3)2 and calcite(CaCO3) are minerals in the carbonate rocks that outcrop throughout most of Missouri. Many of the outcrops of carbonate rocks in Missouri display a dark weathered surface that may contain relatively insoluble components present in the host rock (manganese) and/or microbial organisms (cyanobacteria). Dolomite samples in Missouri were analyzed through ICP-OES, SEM and optical microscopy to identify the composition of the black coatings. The ICP-OES analysis results show that manganese concentration of the black coating dissolved in HNO3 solution is nearly identical to dolomite without black coating (0.097ppm > 0.093ppm). The ratios between Ca and Mg in two HNO3 dissolutions and those in two H2O2 dissolutions have little difference while ratios in H2O2 dissolutions are slightly higher than those in HN O2 dissolutions (1.83 > 1.65). The results indicate that the black coatings on dolomite would be more biogenic in origin than inorganic precipitates of MnO2
Biography
Hang is a senior undergraduate student in the Department of Geological Sciences & Engineering. He studied Petroleum Geology three years in China University of Petroleum in Beijing and was transferred to Missouri S& Tin fall, 2011. He now works as a lab research assistant in Geochemistry and Clay Mineralogy Laboratory in the department and is being trained to work on geosciences perspective in carbon sequestration.
Research Category
Sciences
Presentation Type
Oral Presentation
Document Type
Presentation
Location
Upper Atrium/Hallway
Presentation Date
03 Apr 2013, 9:00 am - 11:45 am
Black Coating on Dolomite in Missouri: Organics or lnorganics Containing Manganese Oxide?
Upper Atrium/Hallway
Dolomite CaMg(CO3)2 and calcite(CaCO3) are minerals in the carbonate rocks that outcrop throughout most of Missouri. Many of the outcrops of carbonate rocks in Missouri display a dark weathered surface that may contain relatively insoluble components present in the host rock (manganese) and/or microbial organisms (cyanobacteria). Dolomite samples in Missouri were analyzed through ICP-OES, SEM and optical microscopy to identify the composition of the black coatings. The ICP-OES analysis results show that manganese concentration of the black coating dissolved in HNO3 solution is nearly identical to dolomite without black coating (0.097ppm > 0.093ppm). The ratios between Ca and Mg in two HNO3 dissolutions and those in two H2O2 dissolutions have little difference while ratios in H2O2 dissolutions are slightly higher than those in HN O2 dissolutions (1.83 > 1.65). The results indicate that the black coatings on dolomite would be more biogenic in origin than inorganic precipitates of MnO2
