Zhucun Fm

The base marked by rhyolitic agglomerate lava and massive dacitic vitric ignimbrite is distinguished from the underlying Jiuliping Fm marked by light gray yellow rhyolite porphyry and shows a conformable contact with the latter.

The top is bounded by the appearance of purple red massive conglomerate of the overlying Tangshang Fm, showing an unconformable contact with the latter.

The formation is distributed in the Longquan-Shangyu and Wencheng-Fenghua small areas of southeast Zhejiang. It varies considerably both in lithology and thickness. In the Longquan-Shangyu small area, it covers a limited area. In the Tiantou area to the east of Zhuji and to the south of Shaoxing, it is 1852.2 m thick; the lower part of the formation is dominated by intermediate lava with tuffaceous sandstone, with a thickness of 1046.5 m thick, while the upper part by intermediate and acidic, and acidic pyroclastic rocks with acidic lava and tuffaceous macroclastic sedimentary rocks, with a thickness of 805.7 m. In the Wencheng-Fenghua small area, the formation is confined to the volcanic depression. In the Shuiche-Baiyan area of Ninghai, it is 1398 m thick. Its lower part is built up by intermediate and acidic pyroclastic rocks; the middle part manly red beds with almost 100 m thick acidic pyroclastic rocks and 14 m thick basalt; while the upper part acidic volcanic pyroclastic rocks with purple red and yellow green siltstone and sediment tuff. In the Chashan of Ninghai, the formation is intercalated with blackish green basalt, andesitic breccia and dacitic porphyrite at the base and in the upper part. The formation is 356-1500 m thick. In Shuiche of Ninghai, it yields estherias Orthestheria intermedia, O. reniformis, etc.