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Full-Text Articles in Physical Sciences and Mathematics
Analysis Of Glasses Present In Quartz And Apatite Phenocrysts From Ordovician K-Bentonites In The Mohawk Valley, Ny, Stefanie Dannenmann
Analysis Of Glasses Present In Quartz And Apatite Phenocrysts From Ordovician K-Bentonites In The Mohawk Valley, Ny, Stefanie Dannenmann
Geology Theses and Dissertations
More than 20 bentonites occur in the Middle Ordovician black shales of the Utica Formation that outcrop along tributaries to the Mohawk River in New York State. Pristine melt inclusions within quartz and apatite phenocrysts are commonly found in at least 40% of the bentonites. Constraints on magmatic processes can be obtained by examining the major-, minor- and trace-element variations among different melt inclusions in quartz and apatite phenocrysts from individual bentonites. The melt inclusions in apatite range in composition from rhyodacitic to rhyolitic, while those in quartz are high-silica rhyolites. Most bentonites within the Middle Ordovician sequence in New …
Pre-Thrust Normal Faults And Post-Tectonic Micas In The Taconic Range Of West-Central Vermont, Nicholas W. Hayman
Pre-Thrust Normal Faults And Post-Tectonic Micas In The Taconic Range Of West-Central Vermont, Nicholas W. Hayman
Geology Theses and Dissertations
New geologic maps show that the Champlain Thrust System traces continuously between Shoreham and Benson, Vermont. The Champlain Thrust System consists of at least three internally imbricated thrust slices in continental shelf facies quartzites and carbonates. From north to south there is a structurally controlled thinning of the Champlain Thrust System, and a climbing in stratigraphic level by the thrusts. Within the Champlain Thrust System are a set of across-strike structures which create offsets in the thrusts and the surrounding lithic map unit boundaries. These structures function as lateral ramps in the thrust system geometry and bound thrust duplexes. Often …