沽源-红山子成矿带流纹岩-粗面岩组合的成因及其与铀成矿的关系

位于燕山和大兴安岭火山岩带接壤部位的沽源-红山子成矿带，是我国重要的以火山岩为含矿主岩的热液型铀成矿带，也是目前正在重点勘查的铀成矿带。该成矿带铀矿床产于流纹岩-粗面岩组合中，与我国东部其它地区及俄罗斯东部、蒙古东部绝大多数以火山岩为含矿主岩的热液型铀矿围岩的岩石组合基本一致，其中460大型铀矿床和470小型铀矿床分别产于沽源盆地流纹岩和红山子盆地粗面岩中。本项目选择沽源、红山子盆地的流纹岩-粗面岩组合和铀矿床为研究对象，采用SHRIMP锆石U-Pb测年技术和元素、Sr-Nd-Pb-O-Hf同位素示踪技术查明流纹岩-粗面岩组合的形成时代、物质来源和形成的构造环境，采用诱发裂变径迹技术查明流纹岩、粗面岩及其蚀变岩石中铀的存在形式和分布状态，采用S-O-H-C同位素示踪技术查明成矿流体的来源，探讨以火山岩为含矿主岩的热液型铀矿的成因，建立流纹岩-粗面岩组合与铀成矿的内在联系和成岩、成矿模式。

Rhyolite-Trachyte assemblage in Guyuan-Hongshanzi uranium mineralization belts located in the adjacent Yanshan to Great Hingan volcanic rock range is hydrothermal uranium mineralization belt of the ore-bearing host rocks of volcanic rock, and the exploring uranium mineralization belt. Uranium deposits atudies have shown that the ocurrence of uranium deposite in this belt is rhyolite-trachyte assemblage. The ocurrence of 460 uranium deposite in Guyuan basin is rhyolite and 470 uranium depossite in Hongshanzi basin is trachyte. Most of hydrothermal uranium deposite of the ore-bearing host rocks existed in early Early Cretaceous rhyolite-trachhyte assemblage in eastern China ,Russian and Mongalian.In this project select the rhyolite-trachyte assemblge in Guyuan and Hongshanzi basin as objects to identify the geological age ,material sources of the rhyolite-trachyte assemblage by means of the SHRIMP zircon U-Pb dating and the element, Sr-Nd-Pb-Hf and S-O-H-C isotope analying, existing forms and distribution characteristics of uranium in the rhyolite-trachyte and the alteration process by means of induced fission tracks,then discuss the genesis of the rhyolite-trachyte assemblage and establish the relationship the rhyolite-trachyte assemblage with uranium mineralization.