Geochronologic and geochemical evidence for persistence of south-dipping subduction to late Permian time, Langshan area, Inner Mongolia (China): Significance for termination of accretionary orogenesis in the southern Altaids

Autor: Li'na Lin, Bo Wan, Jianyun Feng, Chunming Han, Zhiyong Zhang, Wenjiao Xiao, Brian F. Windley, Songjian Ao, Ji'en Zhang
Rok vydání: 2014
Předmět:
Zdroj: American Journal of Science. 314:679-703
ISSN: 0002-9599
Popis: The Langshan area in Inner Mongolia is situated in the southern Altaids between the Beishan suture to the west and the Solonker suture to the east. This paper addresses the poorly known tectonic evolution that led to formation of the terminal Solonker suture. Dating of deformed porphyries and undeformed dolerites and gabbros constrains the timing of the relevant NE-E-striking and north-vergent deformation. Deformed granitic-granodioritic porphyries in this area are characterized by high SiO2 (65.38-78.00%), low TFe2O3 (1.29-5.07%), MgO (0.13-0.63%), and variable K2O (0.53-4.14%) and Na2O (2.05-4.62%). All samples have enriched LREE (La/Yb 6-18) and negative Nb anomalies (NbN/ThN0.09-0.48), but different Eu anomalies (Eu*
Databáze: OpenAIRE