Physical Sciences and Mathematics Commons^™

Provenance Study Of The Middle Ordovician Sandstones Of New York And Western Vermont, Stephen A. Tanski

Geology Theses and Dissertations

Medial Ordovician rocks exposed in westernmost New England and eastern New York State include thick sequences of marine sandstones which are part of a belt extending from Newfoundland to Tennessee. A petrographic study was made of 237 samples distributed across the entire outcrop belt (approx. 250 km. north-south along strike and 190 km. east-west across strike).
Two distinct types of sandstone are recognized, the oldest, and most widespread, is a deep water lithic wacke deposited by turbidity currents and found interbedded with shale (flysch). The younger sandstone is found only in the southeastern part of the study area and is …

The Sedimentary Petrography, Depositional Environment And Tectonic Setting Of The Aldwell Formation, Northern Olympic Peninsula, Washington, Keith Marcott

WWU Graduate School Collection

The upper Eocene Aldwell Formation crops out in an east-west trending band across the northern Olympic Peninsula, Washington. Petrographic analyses indicate that the Aldwell Formation has lithologically distinctive eastern and western portions. The rocks of the eastern Aldwell are basalt-rich lithic greywackes; their mean compositions are Qm-F-Lt: 5- 22-73 and polycrystalline quartz-volcanic rock fragments-total sedimentary rock fragments: 1-78-21. The rocks of the western Aldwell are chert-rich lithic arenites; their mean compositions are Qm-F-Lt: 27-19-54 and polycrystalline quartz-volcanic rock fragments-total sedimentary rock fragments: 66-11-23.

Similarities in texture, composition, and alteration products suggest that the basalts of the Crescent seamount province as …