矿床剥蚀保存与氧化带的热年代学研究：以东天山红山铜-金矿床为例

本课题以东天山红山铜-金矿床为研究对象，在详细的野外地质调查、样品采集和室内鉴定的基础上，通过对赋矿岩体的锆石和磷灰石裂变径迹以及(U-Th)/He等综合年热年代学测试分析，反演成矿后不同阶段的剥露速率、剥蚀量，恢复矿床的剥露历史；运用40Ar/39Ar测试技术，针对矿床氧化带中连续高密度采集的含钾类矿物的样品开展系统的热年代学分析，确定氧化带形成时间，形成条件和次生富集时代。红山铜金矿床是大型高硫化物型浅成低温热液铜-金矿床，氧化带规模大,保存完整，成矿远景广阔，对其进行深入的年代学研究不仅能深化矿床剥蚀程度、保存潜力和次生矿床富集规律的认识，为该区找矿勘探前景评价提供地质理论依据，而且，本研究成果也可为新生代以来高原隆升、全球古气候古地理变化等重要地质事件提供关键制约。

Targeting at Hongshan deposits in the eastern Tianshan, this study explores the denudation and preservation of copper gold ore deposits and conducts the thermal chronology study on their oxidizing zones. Based on the detailed field geological investigation and deliberate sample collection in the metallogenic rock body and surrounding rocks, multiple techniques are involved including the zircon, apatite fission track and (U-Th)/He analysis to reveal the regional uplifting history, geomorphic evolution, erosion degree and the preserving potential. Using the 40Ar/39Ar technology, systematic geochronological analysis is conducted on the potassium-bearing minerals collected continuously in the oxidation zone to determine its formation time, formation conditions and the enrichment age of the secondary deposit. The Hongshan Cu-Au deposit is a large epithermal deposit with high sulfide. It has large oxidation zone with relatively intact preservation, leading to the broad metallogenic prospect. The thorough chronology study allows deeper understanding of the denudation extent, the preserving potential and the secondary enrichment pattern for the ore deposits and supplements the geological exploration prospect evaluation theory. Additionally, high resolution geochronology obtained by the research is expected to provide key constraints for important geological events such as plateau uplift and global paleoclimate and paleogeography changes since the Cenozoic era.