AUTHOR=Shellnutt J. G. , Pham Thuy T. 

TITLE=Mantle Potential Temperature Estimates and Primary Melt Compositions of the Low-Ti Emeishan Flood Basalt

JOURNAL=Frontiers in Earth Science

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2018.00067

DOI=10.3389/feart.2018.00067

ISSN=2296-6463

ABSTRACT=<p>The Late Permian Emeishan large igneous province (ELIP) is considered to be one of the best examples of a mantle plume derived large igneous province. One of the primary observations that favor a mantle plume regime is the presence of ultramafic volcanic rocks. The picrites suggest primary mantle melts erupted and that mantle potential temperatures (<italic>T</italic><sub>P</sub>) of the ELIP were &gt; 200°C above ambient mantle conditions. However, the picrites may represent a mixture of liquid and cumulus olivine and pyroxene rather than primary liquids. Consequently, temperature estimates based on the picrite compositions may not be accurate. Here we calculate mantle potential temperature (<italic>T</italic><sub>P</sub>) estimates and primary liquids compositions using PRIMELT3 for the low-Ti (Ti/Y &lt; 500) Emeishan basalt as they represent definite liquid compositions. The calculated <italic>T</italic><sub>P</sub> yield a range from ~1,400 to ~1,550°C, which is consistent with variability across a mantle plume axis. The primary melt compositions of the basalts are mostly picritic. The results of this study indicate that the Emeishan basalt was produced by a high temperature regime and that a few of the ultramafic volcanic rocks may be indicative of primary liquids.</p>