Research on Trace Element Contents in Granitoids

外带花岗岩类可分为1型和s型两类。产自日本西南外带釜冢构造线北部的花岗岩类多呈i型特征，s型花岗岩类一般局限于南部。除I型和s型区分外，还观察到一些地球化学变化：K_2O、总Fe和正态刚玉向太平洋方向增加，而Fe_2O_3/FeO*（总Fe /FeO）比值减小。在本报告中，我们拟报道Kii半岛Omine地区和四国高冢山岩体的花岗岩类矿物组合。在Omine地区，花岗岩类沿NS走向间歇性分布，长约40 km。I型和s型花岗岩类的分界线位于蒲须三构造线附近。角闪洞的存在是i型花岗岩的矿物组合特征，而角闪洞的不存在和堇青石或石榴石的偶有是s型花岗岩的特征。is型花岗岩类在奥明地区以分离的岩体形式存在。四国的高摫雅那岩体位于Butsuzo构造线以南10公里处。侵入晚白垩世下岛野超群的岩体，根据其野外产状和矿物组合，可将高杉山花岗岩类划分为B-型、W-C型、W-A型三大岩相类型。b型花岗岩类被发现为一个小的卵形体，大小为1 km X 0.5 km，完全封闭在w型岩体的中心部分。B-型和W-A型花岗岩类为i型，W-C型花岗岩类为s型。陆s型花岗岩类在单个岩体内的存在是该岩体的一个特征，这是必须解决的问题。

The Outer Zone granitoids have been divided into two groups, namely, 1- and S-types. The granitoids occurring in the northern part of the Butsuzo Tectonic Line of the Outer Zone of Southwest Japan tend to have I-type characteristics, and S-type granitoids are generally restricted to the south. In addition to I- and S-type discrimination, some geochemical variations have been observed : K_2O, total Fe and normat6ive corundum increase toward the pacific side, while Fe_2O_3/FeO* (total Fe as FeO) ratio decreases. In this report we intend to report mineral assemblages of granitoids of the Omine district in the Kii peninsula and Takatsukiyama pluton in Shikoku. In the Omine district, granitoids are intermittently found along the trend of NS about 40 km long. The boundary of I- and S-type granitoids is located just about the Butsuzo Tectonic Line. The presence of amphibole is the characteristics of mineral assemblage of I-type granitoids, while the absence of amphibole and occasional presence of cordierite or garnet are the characteristics of S-type granitoids. The IS-type granitoids are found as separated plutons in the Omine district. The Takatsukiyarna pluton in Shikoku is located at 10 km south of the Butsuzo Tectonic Line. The pluton intruded into the Lower Shimanoto Supergroup of the Late Cretaceous age Depending on the field occurrence and mineral assembllage, the Takatsukiyama granitoids have been divided into three major petrographic types, namely, B-, W-C, W-A types. The B-type granitoid is found as a small ovoid body, 1 km X 0.5 km size, completely enclosed in the central part of the w-type body. The B- and W-A type granitoids belong to I-type, while the W-C type granitoids belong to S-type. The presence of the Land S-type granitoids within a single pluton is a characteristics of the pluton, and that must be the problem to solve.