二元混合模型在广东塘蓬花岗岩成因和物质来源研究中的应用

Application of Binary Mixing Model in the Studies on the Gensis and Material Sources of Tangpeng Granite in Lianjiang County, Guangdong Province

广东塘蓬岩体中发育两类不同成因及时代的花岗岩，采用Ｒｂ－Ｓｒ等时线年龄测定，确定塘蓬主岩体的成岩时代为海西期（２０４Ｍａ）；应用Ｓｍ－Ｎｄ同位素，采用二元混合模型确定塘蓬岩体黑云母二长花岗岩为改造型花岗岩，黑云母花岗闪长岩为同熔型花岗岩。

Through the study of two types of granites with different ages and genesis, developed in Tangpeng rock body of Lianjiang county, Guangdong Province, the diagenetic age of main rock body of Tangpen has been determined as Hercyian period(204 Ma) by Rb-Sr isochron dating. The binary comprehensive model reveals that biotite adamellite of Tangpen rock body belongs to a granite and biotite granodiorite belongs to syntectic granite. The Tangpeng rock body is composite rock body of multiple intrusion. Its mechanism is also inferred as the geosyncline stage, composed of sedimentary flysch formation and silicalite during pre-Devonian, were folded again into mountains with Caledonian orogeny. As a result, the metamorphism deepened and amphibolite metamorphic rocks and granodiorite formed successively. Then, reformed Tangpeng biotite adamellite were formed small quantity of mantle materials mainly originated from continental crust.