Earth Sciences Commons^™

The Magmatic History Of An Aubrite Parent Asteroid: Evidence From Igneous Clasts And Trace Elements, Maya Monica Wheelock

Earth and Planetary Sciences ETDs

Norton County aubrite contains numerous igneous-textured clasts that survived severe brecciation. These clasts were studied in order to obtain information about the suite of original igneous lithologies that crystallized on an aubrite parent body. The majority of igneous clasts are pyroxenites (enstatite, with minor diopside, +/- forsterite) and orthopyroxenites (enstatite, +/- forsterite). Phase relations and textural evidence are consistent with formation from a nearly pure enstatite magma body or magma ocean, at (or near) the surface of the parent body.

A new sulfide-dominated lithology was identified in Norton County. The sulfide portion is dominated by coarse-grained oldhamite (CaS) containing rounded …

Geochemistry Of Metal Segregation In Aubrites, And The Origin Of Their Metallic Phases, Ignacio Casanova

Earth and Planetary Sciences ETDs

In this work, I have carried out a petrographic and geochemical study of the metallic particles present in aubrites with the aim of constraining ideas about their origin and evolution. The extremely low oxygen fugacities under which enstatite meteorites formed (e.g. Larimer and Buseck, 1974; Fogel et al., 1989) and their consequent unique composition make interpretations difficult due to the lack of experimental data on highly reducing systems. I have tried to overcome the paucity of experimental data by using a theoretical thermodynamic approach to study the significance of such unique compositions based on three main themes: (1) the …

Hydrology Of A Large, Closed Arid Watershed As A Basis For Paleohydrological And Paleoclimatological Studies In The Mojave River Drainage System, Southern California, Yehouda Enzel

Earth and Planetary Sciences ETDs

A physical link between anomalous, present-day atmospheric circulation patterns over the North Pa1cific Ocean, extreme storms in southern California, the largest floods of record and lake stands in the Mojave River watershed in the Mojave Desert is demonstrated by analyzing hydrologic and climatic data. This link is then used as a modem analog to interpret hydroclimatic conditions during the latest Quaternary recorded in lake deposits in the Silver Lake playa, the terminal basin of the of the Mojave River.

The Mojave River filters out small to medium floods by discharge loss through infiltration into the alluvial aquifer and allows only …