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Petrology Of The Paired Dominion Range 2010 Howardites: Indications Of Magmatic Complexity On Asteroid Vesta, Timothy Michael Hahn Jr.

Masters Theses

A comprehensive petrologic and geochemical characterization of six paired howardites collected from the Dominion Range, Antarctica was conducted. These howardites are megaregolith samples from the asteroid 4 Vesta. Collectively, they contain an assortment of igneous rock fragments that indicate magmatic processes were capable of producing a variety of rock types; 22 chemically and texturally discrete basaltic eucrite, cumulate eucrite, and diogenite lithologies are recognized. The implications for remote-sensing observations of Vesta are discussed. The petrogenesis of two previously unrecognized lithologies are described in further detail: an evolved dacite that we propose is a residual melt from extensive crystallization, and a …

Insights Into Planetesimal Evolution: Petrological Investigations Of Regolithic Howardites And Carbonaceous Chondrite Impact Melts, Nicole Gabriel Lunning

Doctoral Dissertations

Asteroidal meteorites are the only available geologic samples from the early part of our solar system’s history. These meteorites contain evidence regarding how the earliest protoplanetary bodies formed and evolved. I use petrological and geochemical techniques to investigate the evolution of these early planetesimals, focusing on two meteorite types: Howardites, which are brecciated samples of a differentiated parent body (thought to be the asteroid 4 Vesta), and CV chondrites, which are primitive chondrites that have not undergone differentiation on their parent body.

Quantitative petrological analysis and characterization of paired regolithic (solar wind-rich) howardites indicate that this large sample of the …

Studies Of Regolithic Vestan Samples: Brecciated Eucrites And Howardites, Sheryl A. Singerling

Masters Theses

Brecciated eucrites and howardites represent samples of the regolith of asteroid 4 Vesta. As such, they are a valuable source of data for understanding the products of surface alteration. Two different processes are investigated here: impact mixing of comminuted rocks to produce regolith samples, and formation of glasses in the regolith.

Chapter 1 describes four newly discovered eucrite breccias: three presumably paired meteorites, all named NWA 6105, and NWA 6106. For each meteorite, major- and minor-element compositions of minerals were determined using the electron microprobe. Pyroxene Fe-Mn co-variations and bulk-rock oxygen isotope compositions confirm their classification as eucrites. Variations in …

Petrology And Geochemistry Of Olivine-Bearing Diogenites And A Group Of Paired Howardites, Andrew William Beck

Doctoral Dissertations

Asteroid 4 Vesta, the largest differentiated body in the asteroid belt, is a protoplanet, much like those that accreted to form the Earth. Understanding the geology of Vesta furthers understanding of early differentiation processes that occurred on Earth and helps define igneous processes occurring on other differentiated bodies in the early solar system. Howardite, eucrite and diogenite (HED) meteorites, which are thought to have originated from Vesta, can be analyzed to better understand the geology of that asteroid. Here my colleagues and I investigate the petrology and geochemistry of two groups of HEDs. This work is timely, in that the …