CLUSTERING ANALYSIS OF CLASTIC ROCKS FOR PROVENANCE IN XIHU DEPRESSION

The clustering analysis of heavy minerals is an important tool for provenance study. According to the Q-type and R-type of heavy mineral clustering and distribution pattern of ZTR contour line for more than 900 samples collected from the Xihu Depression, we discussed hereby the provenance and attributes of the clastic rocks in the Xihu Depression. The research reveals that there are two distinct sediment sources, which correspond to deposits in the north of the depression and in the middle south region. There are five sub-areas in the middle south region, i.e. the sub-areas located in the middle western slope zone, the north of and the south of western secondary sag, the north of and the south of central inverted structure zone respectively. The provenance in the western slope zone consists of two types of rocks, i.e. acid igneous rocks and metamorphic rocks, while the provenance of middle south region is dominated by metamorphic rocks with igneous rocks as the second. The heavy minerals in the northern Xihu Depression come from the Hupijiao Uplift belt and in the middle and south region they are mainly from the Haijiao and Diaoyudao Uplift belt. The two types of provenance are similar in nature.