期刊
GEOLOGY
卷 37, 期 5, 页码 439-442出版社
GEOLOGICAL SOC AMER, INC
DOI: 10.1130/G25530A.1
关键词
-
类别
资金
- Instrumentation and Facilities Program
- Division of Earth Sciences
- National Science Foundation (NSF) [EAR-0510449]
- Jackson School of Geosciences, University of Texas
- Division Of Earth Sciences
- Directorate For Geosciences [0809309, 1051807, 0810152] Funding Source: National Science Foundation
Shallow subduction of the Farallon plate during the Laramide orogeny (ca. 80-40 Ma) may have resulted in metasomatism of the western North American lithospheric mantle. Olivine and orthopyroxene-hosted melt inclusions from the central Rio Grande Rift are variably enriched in chlorine relative to fluid-immobile elements. Subparallel trends in Cl/K versus Cl/Nb for alkali basalts and tholeiites can be explained by Cl/K fractionation during low degree partial melting, with D-Cl approximate to D-Nb < D-K. The observed trace element enrichment does not correlate with host Mg# or melt SiO2 wt% as expected for crustal contamination via an assimilation fractional crystallization (AFC) process. In addition, examples from other volcanic systems suggest that Cl/K decreases with increasing contamination, contrary to observed positive correlations between Cl/K and Ba/Nb and Sr/Nd. The positive correlation of Cl/K and Cl/Nb with typical indices of subduction enrichment (e. g., Ba/Nb and Sr/Nd) supports a model of mantle metasomatism during subduction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据