The Jurassic magmatic and volcanic rocks are widespread along the west central Lhasa subterrane. However, the petrogenesis of these rocks is poorly understood because of lacking high-quality ...geochronology and geochemical data. Here, we present new zircon U-Pb age and Hf isotopic data, whole-rock geochemical and Sr-Nd-Pb isotopic data for the Songduole and Qiangnong plutons in Geji area. LA-ICP-MS dating of zircon yield crystallization ages of 172.1 ± 1.9 and 155.9 ± 1.2 Ma for the Songduole and Qiangnong plutons, respectively. Geochemically, Songduole and Qiangnong granodiorite are characterized by high MgO (2.63-3.49 wt%), high Mg# (49-50), and low TiO2 (0.48-0.57 wt%). Besides, all rocks show metaluminous, calc-alkaline signatures, with strong depletion of Nb, Ta, and Ti, enrichment of large-ion lithophile (e.g. Rb, Th, K), and a negative correlation between SiO2 and P2O5. All these features are indicative of arc-related I-type magmatism. Five samples from the Songduole granodiorite have whole rock (87Sr/86Sr)i of 0.71207-0.71257, epsilonNd(t) values of -15.1 to -13.9, zircon epsilonHf(t) values of -17.4 to -10.5, (206Pb/204Pb)t ratios of 18.402-18.854, (207Pb/204Pb)t ratios of 15.660-15.736, and (208Pb/204Pb)t ratios of 38.436-39.208. Samples from the Qiangnong granodiorite have (87Sr/86Sr)i of 0.71230-0.71252, epsilonNd(t) values of -15.1 to -14.2, zircon epsilonHf(t) values of -12.6 to -6.4, (206Pb/204Pb)t ratios of 18.688-18.766, (207Pb/204Pb)t ratios of 15.696-15.717, and (208Pb/204Pb)t ratios of 38.546-39.083. These geochemical signatures indicate that the two plutons most likely originated from partial melting of the ancient Lhasa lower crust with obvious inputs of mantle-derived melts. Combined with regional geology, our results indicate that the Jurassic magmatism in the west central Lhasa subterrane most likely resulted from the southward subduction of the Bangong Ocean lithosphere beneath the central Lhasa terrane.
This paper deals with the form and function/distribution of the postposition of the agentive referent in transitive clauses through a comparison of 19 dialectal varieties of Qiang. The author ...proposes that the agentive marking in Qiang is not marked for syntactic function (either nominative or ergative case), but reflects semantic/pragmatic constraints; therefore, the marking of the agentive referent just reflects the semantically based nature of grammatical relations in Qiang., 本文在眾多羌語方言土語語料的基礎上，比較和討論羌語施事者標記的形式和分布特徵，提出施事者標記並不區分主語與賓語；只有為了消除語意上的歧義，即辨別哪個所指是施事者時，才使用施事者標記，也就是類型學上所謂的語意基礎上的標記。語意基礎上的標記是指施事者標記是否出現不受句法功能的限制，主要受語意和語用的限制。同時，在羌語中，施事者標記與其他格標記形式相同，本文還探討施事者標記與其他格標記之間的相互關係，以及施事者標記的時間深度
