TY - JOUR
T1 - Geochemistry and geochronology of acidic rocks in the Beishan region, NW China
T2 - Petrogenesis and tectonic implications
AU - Su, Ben Xun
AU - Qin, Ke Zhang
AU - Sakyi, Patrick Asamoah
AU - Liu, Ping Ping
AU - Tang, Dong Mei
AU - Malaviarachchi, Sanjeewa P.K.
AU - Xiao, Qing Hua
AU - Sun, He
AU - Dai, Yu Cai
AU - Yan, Hu
PY - 2011/4/30
Y1 - 2011/4/30
N2 - The dacites and granites from the Beishan region are characterized by highly-fractionated REE, enrichments in LILE, and depletion in Nb, Ta and Sr. The dacites contain zircons with ages ranging from 265 to 748Ma. These features suggest that they were probably derived from the older lower continental crust and were later on subjected to significant crustal assimilation. The rhyolites, diorites and diabases, all of which share similar geochemical features such as trace element patterns, zircon U-Pb ages of ~280Ma, positive εHf(t) and εNd(t), high initial (87Sr/86Sr)i and δ18O‰ values, were most likely derived from the juvenile crustal sources and subsequently experienced fractional crystallization and crustal contamination. These acidic igneous rocks (except dacites and granites) and coeval mafic-ultramafic intrusions form a bimodal igneous series. This implies that the Beishan region was a Late Paleozoic rift probably developed in association with the early Permian mantle plume activity in the Tarim Basin.
AB - The dacites and granites from the Beishan region are characterized by highly-fractionated REE, enrichments in LILE, and depletion in Nb, Ta and Sr. The dacites contain zircons with ages ranging from 265 to 748Ma. These features suggest that they were probably derived from the older lower continental crust and were later on subjected to significant crustal assimilation. The rhyolites, diorites and diabases, all of which share similar geochemical features such as trace element patterns, zircon U-Pb ages of ~280Ma, positive εHf(t) and εNd(t), high initial (87Sr/86Sr)i and δ18O‰ values, were most likely derived from the juvenile crustal sources and subsequently experienced fractional crystallization and crustal contamination. These acidic igneous rocks (except dacites and granites) and coeval mafic-ultramafic intrusions form a bimodal igneous series. This implies that the Beishan region was a Late Paleozoic rift probably developed in association with the early Permian mantle plume activity in the Tarim Basin.
KW - Beishan
KW - Central Asian Orogenic Belt
KW - Dacite
KW - Magmatism
KW - Rhyolite
KW - Zircon U-Pb-Hf-O isotopes
UR - http://www.scopus.com/inward/record.url?scp=79952626588&partnerID=8YFLogxK
U2 - 10.1016/j.jseaes.2010.12.002
DO - 10.1016/j.jseaes.2010.12.002
M3 - Article
AN - SCOPUS:79952626588
SN - 1367-9120
VL - 41
SP - 31
EP - 43
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
IS - 1
ER -