Water and the composition of Martian magmas

Abstract

Research Article| October 01, 2013 Water and the composition of Martian magmas J. Brian Balta; J. Brian Balta Department of Earth and Planetary Sciences, University of Tennessee, 1412 Circle Drive, Knoxville, Tennessee 37996, USA Search for other works by this author on: GSW Google Scholar Harry Y. McSween, Jr. Harry Y. McSween, Jr. Department of Earth and Planetary Sciences, University of Tennessee, 1412 Circle Drive, Knoxville, Tennessee 37996, USA Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (10): 1115–1118. https://doi.org/10.1130/G34714.1 Article history received: 07 May 2013 rev-recd: 11 Jun 2013 accepted: 18 Jun 2013 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. Brian Balta, Harry Y. McSween; Water and the composition of Martian magmas. Geology 2013;; 41 (10): 1115–1118. doi: https://doi.org/10.1130/G34714.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Shergottites, the most abundant martian meteorites, represent the best source of information about Mars' mantle and its dissolved water. If the mantle was wet, magmatic degassing could have supplied substantial water to the martian surface early in its history. Researchers have attempted to reconstruct the volatile contents of shergottite parental magmas, with recent analyses confirming that the shergottites contained significant water. However, water is not a passive tracer; it directly affects magma chemistry and physical properties. Deciphering the history of water on Mars requires understanding how that water affected the chemistry of the shergottites and how they fit within Mars' geologic history. Both topics present difficulties, as no shergottite-like rock has been found in stratigraphic context and there is debate over the timing of eruptions of shergottite-like magmas. Partial melting experiments on terrestrial basalts and new data from orbiters and rovers on Mars provide the information needed to overcome these difficulties and explain the role of water in shergottite magmas. Here we show that shergottite compositions and their martian geologic context can be explained by melting of an originally wet mantle that degassed over time. We also demonstrate that models for the evolution of the martian mantle that do not consider water fail to account for the shergottite compositions, surface distributions, and ages. Finally, we suggest that dehydration of the martian mantle has led to changes in magmatic chemistry over time, with shergottites representing melts of water-bearing mantle and rocks similar to nakhlites representing melts of other mantle sources. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.