Investigation of Sedimentary Structures in the Lucerne Granite, ME, using Feldspar Crystals
Department
Geosciences and Geological and Petroleum Engineering
Major
Geology and Geophysics
Research Advisor
Hogan, John Patrick
Advisor's Department
Geosciences and Geological and Petroleum Engineering
Funding Source
UMR Opportunities for Undergraduate Research Experiences (OURE)
Abstract
This study is examining modal layering and crystal size sorting, in the Lucerne Granite, Maine. The extent to which this layering formed in situ or by mechanical sorting of preexisting crystals is being tested. These layers contain mafic-rich bottoms and coarsening upward feldspar crystals. Petrographic analysis of the feldspar crystals reveal that the feldspar phenocrysts are relatively undeformed, while the matrix is deformed. It is hypothesized that after the phenocrysts formed, the matrix was deformed as it crystallized. The feldspar phenocrysts exhibit a zoned core ringed by a zone with abundant quartz inclusions, surrounded by a margin of feldspar that merges into the matrix. This quartz inclusion texture is evidence for a common crystallization event among the feldspars. A chemical analysis of the feldspar cores will be conducted to determine if the core compositions are similar (in situ) or different (mechanical sorting).
Biography
Cecily J. Sharko is a junior majoring in Geology and Geophysics at the University of Missouri--Rolla. She is the daughter of Dr. Paul T. and Janet Sharko and is from Ridgewood, NJ. She plays alto saxophone in the Miner Marching Band and Concert Band. She also remains active on campus through Tau Beta Sigma and the Catholic Newman Center. Cecily plans on pursuing a Master’s degree in geology after she graduates.
Research Category
Natural Sciences
Presentation Type
Poster Presentation
Document Type
Poster
Presentation Date
12 Apr 2006, 1:00 pm
Investigation of Sedimentary Structures in the Lucerne Granite, ME, using Feldspar Crystals
This study is examining modal layering and crystal size sorting, in the Lucerne Granite, Maine. The extent to which this layering formed in situ or by mechanical sorting of preexisting crystals is being tested. These layers contain mafic-rich bottoms and coarsening upward feldspar crystals. Petrographic analysis of the feldspar crystals reveal that the feldspar phenocrysts are relatively undeformed, while the matrix is deformed. It is hypothesized that after the phenocrysts formed, the matrix was deformed as it crystallized. The feldspar phenocrysts exhibit a zoned core ringed by a zone with abundant quartz inclusions, surrounded by a margin of feldspar that merges into the matrix. This quartz inclusion texture is evidence for a common crystallization event among the feldspars. A chemical analysis of the feldspar cores will be conducted to determine if the core compositions are similar (in situ) or different (mechanical sorting).
