地质通报2016，Vol.35Issue(8)：1281-1290,10.
西藏班公湖-怒江缝合带中西段早白垩世洋岛火山岩岩石学及地球化学特征
The petrology and geochemistry of Early Cretaceous ocean island ;volcanic rocks in the middle-western segment of Bangong Co-Nujiang suture zone
摘要
Abstract
Zhonggang ocean island lies in the middle-western segment of Bangong Co-Nujiang suture zone. Previous researches mainly focused on the eastern segment of Zhonggang ocean island, with no attention paid to Dongco area in the middle segment. In this paper, the authors studied the rock association and whole rock geochemistry of Zhonggang ocean island and analyzed the source area and structural environment of the island volcanic rocks. Eight basalt and eight basaltic andesite geochemical samples were collect⁃ed along a transect at the middle part of Zhonggang ocean island in the north of Dongco. The major element characteristics of these two kinds of rocks indicate that basalt is alkali basalt enriched in Ti, and the trace element characteristics show that both of them are enriched in Nb and Ta. The REE patterns and the trace element spider diagram are similar to features of typical OIB. Chemical com⁃positions of Zhonggang ocean island basalts and basaltic andesites suggest that they probably came from the same magma source, and both of them had mantle source with OIB characteristics;the depletion of Cr, Ni indicates that fractional crystallization of olivine and augite occurred during the rock-forming process. The ocean island was formed in an oceanic island tectonic environment on the base of the oceanic crust.关键词
班公湖-怒江缝合带/仲岗洋岛/洋岛火山岩/岩石学/地球化学Key words
Bangong Co-Nujiang suture/Zhonggang ocean island/island volcanic rocks/petrology/geochemistry分类
天文与地球科学引用本文复制引用
于云鹏,胡培远,李才,解超明,范建军,许伟,刘金恒..西藏班公湖-怒江缝合带中西段早白垩世洋岛火山岩岩石学及地球化学特征[J].地质通报,2016,35(8):1281-1290,10.基金项目
国家自然科学基金项目（批准号41402190、41272240）、中国地质调查局项目（编号12120113036700）和中国地质科学院地质研究所基本科研业务费项目 （）
