关键词: 地球化学特征, 碰撞型花岗岩, 早寒武世, 呼中地区, 黑龙江省

Abstract:

The petrographic type of the Early Cambrian granites in the Huzhong area of Heilongjiang Province, is proved to be monzonitic granite, the Early Cambrian granites are divided into four intrusive periods based on the cognate magma evolution theory,and the rock structures show  that the granularity evolutive tendency is from fine grain to coarse grain in the texture. The character of rock geochemistry shows that SiO₂＞70%, Na₂O/K₂O ＜1,and the rocks attribute calcic-alkalic rocks, corindon occurs and diopside does not occur in the standard minerals, the rocks attribute granites of  S type;δ（Eu）＞0.5 shows the rocks belong to weak depletion on Eu,⁸⁷Sr/⁸⁶Sr＞0.706 indicates the Early Cambrian granites were fomed by the old crust melting.Various of rock geochemical indexes show that the rock's geochemical characteristics are the same as collision granites, and the Early Cambrian granites conform to collision granites of Tibet and Oman. The magmatic activity of collision granites  provides the information about the tectonic dynamics from the continental margin epicontinental of the south of Erguna block in the Neo-proterozoic to Early Cambrian.

Key words: geochemical characteristic, collision granite, Early Cambrian, the Huzhong area, Heilongjiang Province