矿床地质2012，Vol.31Issue(3)：506-516,11.
浙江衢州新路火山岩盆地西段热点作用及其对铀成矿的控制作用
Hotspot action and its controlling role in uranium metallogenesis in west segment of Xinlu volcanic basin within Quzhou City, Zhejiang Province
摘要
Abstract
Xinlu volcanic basin is not only a significant base for uranium production but also the only uranium ore district for exploration in Zhejiang Province at present. In order to make a breakthrough in uranium prognoses, the authors explained the formation mechanism of uranium deposits based on studying the hotspot action in the study area so as to gain confidence in finding concealed deep uranium resources. According to the geophysical deep profile, the relatively low velocity fluid occurs at the depth of -40 km, and the relatively high-velocity magma intrusion occurs in upper strata; there are four magmatic cycles from Mesozoic in the study area; there are also three tiers of stratigraphic configuration showing the obvious hotspot action with the lower tier being metamor-phic basement, the middle tier being slippage strata, and the upper tier being lava and Cretaceous sediments. An analysis of fluid inclusions indicates that the metalbgenic hydrothermal temperature is 317 ～ 420℃, salinity ω(NaCleq) is 39.76%～49.68%, and the hydrothermal fluid is composed of CO,OH- , H2O, halogen, N2, metal elements suggesting features of mantle fluid. Metallogentic hydrothermal fluid originated from the upper mantle or the lower crust, as evidenced by an analysis of trace elements and sulfur isotopes associated with uranium element. The hotspot metallogenesis occurred here. An integrated geophysical and geochemical investigation was made and, on such a basis, a model of hotspot action in the study area was established. There are four aspects reflecting uranium metallogenesis controlled by the hotspot: (1) basic magma in deep melts partially with salic rock formed acid magma, which then erupted and resulted in the formation of Xinlu volcanic basin or in-trudeed and resulted in the generation of secondary volcanic rock and acid intrusive rock. All of these products would provide favorable strata or wall rock for metallogenesis; (2) To some extent, a series of faults occurred as a result of mantle plume, which were U-bearing hydrothermal transferring structure or storing structure of -mineralization in the process of uranium metallogenesis; (3) Part of uranium was extracted from altered wall rock, resulting from heat energy due to the upheaval of the mantle plume; (4) The concentration of useful components increased in magma because of differentiation, thus providing the metallogenic material.关键词
地质学/火山岩/热点识别/铀成矿/浙江衢州Key words
geology, volcanic rock, identification of hotspot, uranium metallogenesis, Quzhou in Zhejiang Province分类
管理科学引用本文复制引用
刘蓉蓉,韩效忠,李子颖,汤江伟,杜江浩,金淼张,徐小奇..浙江衢州新路火山岩盆地西段热点作用及其对铀成矿的控制作用[J].矿床地质,2012,31(3):506-516,11.基金项目
本文得到国家“863”计划(2012AA061801)、全国矿产资源潜力评价之子项目“全国铀矿资源潜力评价”及工业与信息部国防科学局核能开发三期的共同资助 （2012AA061801）
