Physical Sciences and Mathematics Commons^™

Formation Of Evolved Rocks At Gale Crater By Crystal Fractionation And Implications For Mars Crustal Composition, Arya Udry, Esteban Gazel, Harry Y. Mcsween Jr.

Geoscience Faculty Research

The recent discovery of some ancient evolved rocks in Gale crater by the Curiosity rover has prompted the hypothesis that continental crust formed in early Martian history. Here we present petrological modeling that attempts to explain this lithological diversity by magma fractionation. Using the thermodynamical software MELTS, we model fractional crystallization of different Martian starting compositions that might generate felsic igneous compositions like those analyzed at Gale crater using different variables, such as pressure, oxygen fugacities, and water content. We show that similar chemical and mineralogical compositions observed in Gale crater felsic rocks can readily be obtained through different degrees …

Diversity And Petrogenesis Of Rhyolites From An Intra-Oceanic Arc: Evidence From Iodp Site U1437, Izu Bonin Rear-Arc And Surrounding Area, Luan J. (Luan Jean) Heywood

WWU Graduate School Collection

Magmas from the Izu Bonin rear-arc show a geochemical signature (medium- to high-K and light rare-earth element [LREE] enriched) that resembles the average composition of the continental crust. I investigate that continent-like signature by examining a suite of rear-arc-derived mafic to felsic tephras from International Ocean Discovery Program (IODP) Site U1437, which was drilled as part of IODP Expedition 350. Volcaniclastic glasses from Site U1437 comprise a compositional series from basalt to rhyolite, aged 1.1-4.4 Ma.

Site U1437 tephras record the timespan when the Izu-Bonin arc began rifting and provide a well-dated record of changing magmatic compositions through the transition …