摘要
浙江萤石矿床的矿化年龄约为80 Ma。无论萤石矿床是产于火山岩还是花岗岩中,矿化年龄总是比围岩的成岩年龄要滞后约60 Ma。作者认为,浙江脉状萤石矿床的形成受制于统一的成矿作用-古地热水环流汲取作用。
Presented in this paper are seven fission-track and two K-Ar dates from four fluorite deposits in Zhejiang Province. The results show that the fluorite deposits occurring in the central Zhejiang upwarping zone and the northwestern Zhejiang depression, two geotectonic units separated by the Jiangshan-Shaoxing fault, have the same age with respect to their mineralization (80±Ma). No matter where the fluorite deposits occur, either in volcanic rocks or in granites, the age of fluorite mineralization is always 60 ±Ma later than that of host rocks. Geological observations indicate that these fluorite deposits were formed after intrusive granitic magma or extrusive lava-clast had chilled and solidified and then undergone weathering-and erosion. The above facts are consistent with previously reported Sr, H and O isotope data for fluorite deposits in the central Zhejiang upwarping zone. Evidence rules out the possibility that ore-forming material for fluorite directly came from post-magmatic pneumato-hydrother-mal solutions produced in the process of magmatic differentiation. It is considered that the formation of vein fluorite deposits in Zhejiang Province is controlled by a genesal mineralization---the circulation-extraction by paleogeothermal waters.
出处
《地球化学》
CAS
CSCD
北大核心
1989年第2期181-188,共8页
Geochimica
