北淮阳金寨—苏仙石地区中生代花岗岩类岩石学及地球化学特征

PETROLOGICAL AND GEOCHEMICAL FEATURES OF THE GRANITOID IN MESOZOIC ERA IN JINZHAI—SUXIANSHI AREA, BEIHUAIYANG

位于大别山北麓的北淮阳金寨—苏仙石地区广泛发育花岗岩类侵入岩，同位素年龄为１４０～９７Ｍａ，时代属Ｊ３—Ｋ１。根据侵入岩的地质、岩石学和岩石地球化学特征，将本区侵入岩划分为３个超单元（包括１０个单元）和３个独立单元，分属中性岩和酸性岩两大类，岩石类型有闪长岩、二长岩和花岗岩等。根据岩石化学的判别结果，侵入岩均属亚碱性系列中的钙碱性岩石。

Beihuaiyang Jinzhai Suxianshi area, which is located to the north of Dabie mountains, has dramatical magmatic activity under the influence of tectonic rift belt of E W trend or NW SE trend. Moreover, there are lots of intrusive rocks developing. The age by K Ar method and\ 40 Ar / 39 Ar method is 140～97Ma, which is considered to be Late Jurassic Early Cretaceous. According to the characteristics of time space relationship between magmatic activity and magmatic evolution, the intrusive rocks are grouped into three super units (include 10 units) and 3 independent units, respectively belong to intermediate rock and acid rock. The variety of the rocks includes diorite, monzodiorite, quartz monzonite, fine granite, porphyritic granite and graphophyre etc.. On the basis of the petrochemistry analysis results, the intrusive rocks all belong to the calc alkalic series rock of subalkalic series, and to general type and potassic type as well.