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Full-Text Articles in Physical Sciences and Mathematics

Geochemical Analysis Of The Chinchín Formation In Southern Ecuador, Katherine Ludwig May 2019

Geochemical Analysis Of The Chinchín Formation In Southern Ecuador, Katherine Ludwig

Celebration of Learning

The subduction of the Nazca Plate under the South American Plate has led to the uplift of the majority of the Andes Mountains, but in Ecuador, the Nazca Plate subducts underneath the North Andes Plate, which then collides with the South American Plate. This tectonic setting has formed two parallel mountain chains as well as a complex series of basins between them. However, the formations that make up these basins are poorly understood. This study focuses on the Chinchín Formation, an ~3.5 km thick, volcanic formation that serves as the bedrock of the Quingeo Basin in southern Ecuador. This study …


Source, Transport, And Age Of Sediment From Cascade Volcano Watersheds To The Nearshore: Insights For Contaminant And Ecological Studies, Renee Takesue, Kathy Conn, Margaret Dutch Apr 2018

Source, Transport, And Age Of Sediment From Cascade Volcano Watersheds To The Nearshore: Insights For Contaminant And Ecological Studies, Renee Takesue, Kathy Conn, Margaret Dutch

Salish Sea Ecosystem Conference

Inputs of sediment and sediment-bound contaminants from urbanized watersheds to the nearshore region are a growing concern as coastal populations increase around the Salish Sea and worldwide. Geochemical sourcing and aging of nearshore sediment is one potential way to: a) distinguish land-derived sediment in nearshore environments, b) gain insights about how sediment and contaminants are redistributed, and c) determine how recently they were deposited. Sediments from Cascade volcanoes have distinct geochemical compositions that allow discrimination between land-derived (volcanic) and marine (lowland) sediment. As sediment is transported by rivers to the nearshore, it adsorbs particle-reactive contaminants and short-lived radionuclides, and the …


The Petrology And Geochemistry Of The Independence Dike Swarm, Owen’S Valley, California, Sean B. O'Donnell Apr 2016

The Petrology And Geochemistry Of The Independence Dike Swarm, Owen’S Valley, California, Sean B. O'Donnell

The Research and Scholarship Symposium (2013-2019)

Petrologic studies are important because they provide insights into the conditions under which rocks form. The Late Jurassic Independence Dike Swarm is a series of vertical igneous dikes that crop out in eastern and southern California, and range from mafic to felsic in composition. In order to examine their petrology and geochemistry, surface samples were collected from four different dike outcrops within Owen’s Valley, CA. The samples were examined through thin-section analysis under a petrographic microscope, X-ray diffraction analysis, and X-ray fluorescence analysis. Mineral composition, mineral size, major, trace, and rare earth element concentrations were collected from these analyses. Results …


Nwa 8614: The Least Heated Winonaite, Karla Farley, Alexander M. Ruzicka, Katherine Armstrong May 2015

Nwa 8614: The Least Heated Winonaite, Karla Farley, Alexander M. Ruzicka, Katherine Armstrong

Student Research Symposium

Northwest Africa 8614 is classified as a winonaite on the basis of oxygen isotope ratios, mineralogy, and highly reduced chemistry. Unlike other winonaites, it contains numerous and readily apparent chondrules. Here we discuss various features of NWA 8614 and the possible significance of the meteorite.

Petrological and chemical analyses were performed using optical microscopy with a DM2500 Leica petrographic microscope and a Zeiss Sigma VP-FEG scanning electron microscope (SEM) with a high-efficiency energy dispersive spectrometer (EDS). Oxygen isotopes were analyzed by Karen Ziegler at the University of New Mexico on acid-washed samples to remove terrestrial weathering products.

Owing to the …