NW Univ Xian, Dept Geol, Xian 710069, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100080, Peoples R China
The volcanic rock slab in Lianghe area is located in the boundary tectonic zone: Bashan arcuate tectonic melange between Qinling microplate and Yangtze plate. The rocks consisted of subalkaline tholeiitic basalt and calc-alkaline dacitic rhyolite. Both of the basalt and dacitic rhyolite exhibit the typical geochemical features of high content of element Bar low content of elements Th and U. remarkable depletion of element Nb, Ta and Ti. Especially, the Th/Yb-Ta/Yb and Ti/Zr-Ti/Y features of the basalt indicate that the volcanic rock association in the studied area developed in a special tectonic setting which belongs to a rift valley within an island-arc. The volcanic rock association in the studied area was the result of magmatism that due to the ancient oceanic crust subduction and rift valley development within the island-arc during the evolutionary process of Mianlue ancient ocean basin at Middle Paleozoic-Early Mesozoic era. This volcanic rock block should be an important evidence which indicates that the Mianxian-Lueyang suture zone had extended to the Bashan arcuate area.
Lai, SC,Zhang, GW,Yang RY,et al. Geochemistry of the volcanic rock association from Lianghe area in Mianlue suture zone, southern Qinling and its tectonic significance.[J]. ACTA PETROLOGICA SINICA,2000,16(3):317-326.
Lai, SC,Zhang, GW,杨瑞英,&Yang, RY.(2000).Geochemistry of the volcanic rock association from Lianghe area in Mianlue suture zone, southern Qinling and its tectonic significance..ACTA PETROLOGICA SINICA,16(3),317-326.
Lai, SC,et al."Geochemistry of the volcanic rock association from Lianghe area in Mianlue suture zone, southern Qinling and its tectonic significance.".ACTA PETROLOGICA SINICA 16.3(2000):317-326.