Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Physical Sciences and Mathematics
Provenance Of And Age Of Granitoid And Sandstone Clasts In Conglomerates Of The Paleocene To Upper Cretaceous Yakutat Group, Russell Fjord, Alaska, Alexander Dolcimascolo
Provenance Of And Age Of Granitoid And Sandstone Clasts In Conglomerates Of The Paleocene To Upper Cretaceous Yakutat Group, Russell Fjord, Alaska, Alexander Dolcimascolo
Honors Theses
The Paleocene to Upper Cretaceous Yakutat Group consists of a flysch facies. A conglomerate occurs in two places in Russell Fjord, and the composition and age of clasts bears on tectonic reconstructions. One site (#23) occurs in what is mapped as flysch and one in the mélange (#25), but the conglomerates are essentially identical. They contain clasts of sandstone, greenstone, limestone, marble, chert, and plutonic rocks that are clast supported, and interbedded with sandstones that contain coalified plant fragments. The maximum depositional age (MDA) of the U/Pb-dated zircons from the sandstone is 65.9 ± 1.8 Ma and 65.6 ± 2.2 …
Geochemical And Petrographic Analysis Of Gore Mountain Garnets, Adirondacks Ny, Elizabeth R. Morgan
Geochemical And Petrographic Analysis Of Gore Mountain Garnets, Adirondacks Ny, Elizabeth R. Morgan
Honors Theses
The mine at Gore Mountain is famous for its giant garnets and long history of garnet abrasive production. This location, Warrensburg (Wall St.), and others were examined to attempt to better understand the petrogenesis of these remarkable rocks. Our studies have emphasized the geochemistry of bulk rocks and rock and mineral separates (122 analyses), thin section petrology, and thermodynamic modeling of mineral assemblages. At Gore Mtn. the ore has the assemblage hornblende-plagioclase-garnet-OPX-biotite, and formed over a ~2 m thick transition zone from a layered olivine corona gabbro, metamorphosed at granulite facies. Petrographically the delicate corona structures and fine-grained garnets were …