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Full-Text Articles in Physical Sciences and Mathematics
Extreme Oxygen Isotope Zoning In Garnet And Zircon From A Metachert Block In Melange Reveals Metasomatism At The Peak Of Subduction Metamorphism, F. Zeb Page, Emilia M. Cameron, Clara Margaret Flood, Jeffrey W. Dobbins, Michael J. Spicuzza, Kouki Kitajima, Ariel Strickland, Takayuki Ushikubo, Christopher G. Mattinson, John W. Valley
Extreme Oxygen Isotope Zoning In Garnet And Zircon From A Metachert Block In Melange Reveals Metasomatism At The Peak Of Subduction Metamorphism, F. Zeb Page, Emilia M. Cameron, Clara Margaret Flood, Jeffrey W. Dobbins, Michael J. Spicuzza, Kouki Kitajima, Ariel Strickland, Takayuki Ushikubo, Christopher G. Mattinson, John W. Valley
Faculty & Staff Scholarship
A tectonic block of garnet quartzite in the amphibolite-facies melange of the Catalina Schist (Santa Catalina Island, California, USA) records the metasomatic pre-treatment of high-delta O-18 sediments as they enter the subduction zone. The block is primarily quartz, but contains two generations of garnet that record extreme oxygen isotope disequilibrium and inverse fractionations between garnet cores and matrix quartz. Rare millimeter-scale garnet crystals record prograde cation zoning patterns, whereas more abundant similar to 200-mu m-diameter crystals have the same composition as rims on the larger garnets. Garnets of both generations have high-delta O-18 cores (20.8 parts per thousand-26.3 parts per …
The Molluscan Taphofacies Of And Influence Of Callianassid Shrimp On A Carbonate Lagoon (St. Croix, Us Virgin Islands), Rowan Lee
Honors Papers
Sediments collect in reef lagoons, and the shells within these can record changes in the environment as they accumulate. Smuggler’s Cove (St. Croix, USVI) has been accumulating a sediment package for at least 5,000 years based on radiocarbon ages. Callianassid shrimp severely bioturbate this lagoon’s sediment package by moving shell material into shelly, subsurface lags that have a high chance of becoming fossilized. Shell condition (taphonomy) was compared between surface and lag to see whether the lag is an accurate representation of the living surface fauna. Guild membership, taxon, and mollusk size between surface and lag assemblages were analyzed. It …