浙江三界、谷来地区1/5万区域地质调查工作的主要进展

三界谷来地区主要出露中、新生代火山岩。进行 １／５万区域地质调查时，采用火山活动旋回－火山构造－火山地层－岩相、岩性－体化思路，按照同旋回火山机构或火山喷发区为单元，确定岩石地层单位和填图单元。火山岩划分为九种岩相类型，建立了两个岩相模式和一个三相一体成因模式。根据火山岩浆作用的旋回性及其产物与火山构造形迹时、空、成因一致性原理，将中、新生代火山岩浆作用分为四个火山活动旋回，圈定了相应的火山机构或火山喷发中心，建立了竹田头复活破火山演化模式。新生代玄武岩中发现二辉斜长麻粒岩等深源包体，为研究区域深部地质作用过程提供了证据。侵入岩按岩石谱系单元划分了七个岩石单元一个超单元，将侵入岩－潜火山岩－火山岩作为岩浆作用整体研究，为正确阐明岩浆作用及其演化规律奠定了基础。区域线型构造发育，与环形火山构造组合，形成火山岩区特有的线一环构造格局。中上元古界陈蔡群变质岩划分为上、下两个岩组，探讨了变质岩的原岩性质及其形成的大地构造环境。

THE ADVANCEMENT OF GEOLOGICAL SURVEY(1/50000) IN SHANJIE AND GULAI AREAS, ZHEJIANG

The crops in Shanjie and Gulai areas are mainly Mesozoic-Cenozoic volcanic rocks. In geological survery, the rock stratigraphy and mapping units are ascertained by volcanic active cy- cl- tructure-stratigraphy-facies-lithology in the same volcanic mechanism or eruption area. The volcanic rocks are divided into 9 facies and set up 2 facies patterns and three facies in one original model. The Mesozoic-Cenozoic volcanism is divided into four cycles and defined relevant volcanic mechanism and erupting center and the evolution model of Zhutiantou caldera is set up according to the volcanic cycle and trace of volcanic structure. The websterite plagioclase granulite xenoliths were found in Cenozoic basalt, which is the key to know the geological process in deep. The intrusive rocks are divided into 7 rock units and a supper unit. The intrusive rock- crytovolcanic rock-volcanic rook are studied as a system to expound the magmatism and its evolution. The regional line structure and ring structure form special line-ring structure in the volcanic area. The middle-upper Proterozoic Chencai group is divided into two units to discuss the original rock of metamorphic complex and regional tectonic environment in its formation.