微量元素模拟限定大别造山带中生代花岗岩类的源岩成分

大陆碰撞造山带中花岗岩浆主要是因下部地壳缺乏流体熔融过程而形成的。对其源岩成分限制而进行的微量元素模拟不仅要考虑源岩和熔体中有关矿物相比例的变化，还要考虑熔融过程中源岩矿物相组合的变化，并选择合适的元素用于模拟。Ｒｂ、Ｓｒ、Ｂａ和ＲＥＥ模拟结果显示，上溪群杂砂岩作为扬子隆起带中生代花岗岩类的源岩是不合适的：大别隆起带中的中生代花岗岩类也不可能完全由大别杂岩中的ＴＴＧ质片麻岩熔融形成，更可能是变基性岩和ＴＴＧ质片麻岩构成的复合源岩熔融的结果

TRACE ELEMENT MODELLING TO CONSTRAIN ON SOURCE COMPONENTS OF MESOZOIC GRANITOIDS FROM DABIE OROGEN

The granitic magmas from collisional orogenic belts are the results of fluid absent melting in the lower crust. In order to constrain on source components of granitoids, trace element modelling not only considers change of minerals ratios both in source rocks and melts, but also must consider change of mineral assemblages in source rocks during partial melting, and the suitable trace elements must be chosen. In this paper, modelling of Rb, Sr, Ba, REE shows that graywackes of Shangxi Group as source component of Mesozoic granitoids from Yangtze uplift belt is not suitable; not all the Mesozoic granitoids from Dabie uplift belt are possible by melting of TTG gneisses in Dabie complex, but products of melting of composite source components that consist of both metabasic rocks and TTG gneisses.