Identifier	Thesis 1741
Author	Rossetti, Sara M. (Sara Marie)
Title	Metamorphic Isograds and their Relationship to Macro and Micro Structures
Publisher	Central Connecticut State University
Date of Publication	2003
Resource Type	Master's Thesis
Abstract	The hypothesis that increased stress on rocks induced during deformation produced microstructures on minerals, which gradually intensifies as one gets closer to an isograd line. This assumption is based on increasing microfractures in the fold direction. The study of metamorphic isograds as related to micro-stress fractures in the Old Lyme Quadrangle of Connecticut was studied and evidence was gathered to support this hypothesis. The work to provide evidence that my hypothesis may be correct began in Lyme Connecticut just outside of the Nehantic State Park. I worked southward into the town of Old Lyme. Clusters of outcrops were located in several different areas. When an outcrop was found, strike and dip measurements were taken to determine the rock's position in space. A rock sample was collected from each outcrop for laboratory study. Once field studies were completed in Lyme and Old Lyme the next phase began. With the rock outcrops' strikes and dips measured and samples collected, thin sections were made. When the samples were analyzed, a noticeable increase in the number of microcracks was observed the closer the rock samples came to an isograd. More microcracks found in a sample indicated that more intense stress occurred in that area. With the evidences obtained from thin sections, rose diagrams were produced. The rose diagrams helped provide the statistics supporting the hypothesis. Through the field and laboratory work conducted, it became very evident that extreme stress occurred during folding episodes. The increase in microcracks as one approaches an isograd was evidence of increasing strain in the rocks as noted in the fold structures. The macrostructures with obvious strain shown in them, indicated clearly that my hypothesis was correct. Also, the index minerals found in various areas are produced under a certain amount of increasing pressure and temperature. Higher pressure-temperature minerals occurred closest to the isograd (index minerals), which are also the minerals indicating the most strain.
Subject	Rocks -- Fatigue -- Connecticut -- Old Lyme Rocks -- Fatigue -- Connecticut -- Lyme Rocks, Metamorphic -- Connecticut -- Old Lyme Rocks, Metamorphic -- Connecticut -- Lyme
Department	Department of Physics and Earth Science
Advisor	Baskerville, Charles A
Type	Text
Digital Format	application/pdf
Language	eng
OCLC number	713734362
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Metamorphic Isograds and their Relationship to Macro and Micro Structures

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