海洋地质与第四纪地质2012，Vol.32Issue(2)：65-75,11.DOI:10.3724/SP.J.1140.2012.02065
滇西腾冲新生代火山岩岩石地球化学特征
GEOCHEMISTRY OF CENOZOIC VOLCANIC ROCKS FROM TENGCHONG, WESTERN YUNNAN
徐翠玲 1赵广涛 2何雨旸 1李德平1
作者信息
- 1. 中国海洋大学 海洋地球科学学院,青岛 266100
- 2. 中国海洋大学 海底科学与探测技术教育部重点实验室,青岛 266100
- 折叠
摘要
Abstract
Tengchong Cenozoic volcanic rocks, which consist of basaltic trachy-andesite, trachy-andesite, and basaltic andesite, belonging to the high-K and calc-alkaline series, are continental intraplate volcanic rocks erupted after the Tethys Ocean was closed. They are distributed near the collision zone of the Indian plate and the Eurasian plate. The geochemical features of the rocks can be used to define the tectonic properties and magma sources. The systematic geochemical study of the typical rock samples by XRF and ICP MS shows that the rocks are characterized by high K2O，CaO, low TiO2，and high Mg # (averaging about 46). REE shows a LREE-enriched pattern with significantly negative Eu. Large ion lithophilc elements (LILE) and high field strength elements (HFSE) are enriched compared to the primitive mantle, and the LILE have higher enrichment than the HFSE. Th shows a significantly positive anomaly. The geochemical composition of the studied volcanic rocks is similar to the volcanic arc magma, suggesting that the magmat-ic activity was triggered by the subduction of the Indian plate down to the Eurasian plate. Characteristic element ratios show that the magma may be derived from the subduction-related EM I mantle.关键词
地球化学/岛弧/火山岩/新生代/腾冲Key words
geochemistry/ island arc/ volcanic rocks/ Cenozoic Era/ Tengchong分类
天文与地球科学引用本文复制引用
徐翠玲,赵广涛,何雨旸,李德平..滇西腾冲新生代火山岩岩石地球化学特征[J].海洋地质与第四纪地质,2012,32(2):65-75,11.
