%0 Journal Article
%T Geochemistry and petrogene-sis of Jurassic high Sr/low Y granitoids in eastern China:Constrains on crustal thick-ness<br>
%A GE Xiaoyue
%A LI Xianhua
%A CHEN Zhigang
%A LI Wuping
%A <br>
%J 科学通报(英文版)
%D 2002
%I 
%X The Jurassic high Sr/low Y granitoids in eastern China are characterized by high Sr/Y (27-166) and La/Yb (14-66) ratios, low abundance in Y (6-21 μg/g) and Yb (0.5-2.0 μg/g), comparable with those of adakites defined by Defant et al. Thus, they were recently considered as adakitic rocks by some researchers. Compared with the typical adakites in circum-Pacific margins, however, these high Sr/low Y granitoids have higher K2O (-3.5%) but lower Al2O3 (-16.0%) as well as lower Mg# (-38) and δ SrN (-1.23) values. Furthermore, they show relatively flat HREE patterns with Y/Yb values of ?10 close to the chondritic value. These geochemical characteristics indicate a residue mineral assemblage of hornblende, garnet and plagioclase for these high Sr/low Y granitoids melt. Thus, they were generated by partial melting at 9-13 kbar (30-45 km in depth), similar to the Archaean high-Al TTG rather than the modern adakites. Generation of these high Sr/low Y granitoids cannot be considered as evidence for a thickened crust (>50 km) and/or the presence of the "Eastern China Plateau" in Jurassic.
%K granitoids
%K adakite
%K TTG
%K Jurassic
%K eastern China<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=01BA20E8BA813E1908F3698710BBFEFEE816345F465FEBA5&cid=96E6E851B5104576C2DD9FC1FBCB69EF&jid=DD6615BC9D2CFCE0B6F945E8D5314523&aid=F67EF2551900E3FEE5C203AAFE3DE797&yid=C3ACC247184A22C1&vid=F4B561950EE1D31A&iid=708DD6B15D2464E8&sid=CFC2B32D03D9F610&eid=20154CF366EC08B1&journal_id=1001-6538&journal_name=科学通报(英文版)&referenced_num=0&reference_num=52