裂变径迹技术及其地质应用  

Fission track technology and its geological applications

作　　者：杨莉 袁万明 洪树炯 冯子睿 YANG Li;YUAN Wanming;HONG Shujiong;FENG Zirui(Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China)

机构地区：[1]中国地质大学(北京),科学研究院,北京100083

出　　处：《中国地质调查》2022年第3期104-112,共9页Geological Survey of China

基　　金：国家自然科学基金项目“战略性关键金属超常富集成矿动力学(编号:92062217)”;“钼同位素在岩浆热液系统的分馏机制(编号:41730427)”;2021年度中国地质大学(北京)研究生创新资助项目“茶卡北山Li-Be等关键金属成矿带隆升剥蚀研究(编号:YB2021YC021)”联合资助。

摘　　要：裂变径迹技术以样品用量少、封闭温度低以及测年范围广等优势,被广泛应用于地质学研究中。完全退火或部分退火样品可有效记录岩体的冷却-剥露历史,限制构造活动起始时间,探讨上覆岩石的风化剥蚀历史与矿床保存变化之间的关系,定量化矿床隆升剥蚀量,实现找矿预测;锆石裂变径迹封闭温度对应天然气生成温度区间,可运用于油气勘探研究计算中;近年来结合元素含量分析的裂变径迹技术还可进行物源分析,LA-ICP-MS技术的引进为测量低U含量矿物的径迹带来了曙光。系统总结了磷灰石与锆石裂变径迹退火特性的研究成果,以及温度、化学成分、结晶各向异性及D_(par)值等因素对磷灰石径迹退火特性数据解释可能产生的影响,锆石径迹热稳定性的降低主要受制于辐射损伤效应。实验室退火特性研究为了解繁杂的径迹退火化学动力机制提供了重要的理论参考,但在实际的数据解释中需结合地质背景,以获得更为清晰的地质热事件演化研究时间格架。结合径迹测年在矿床、山体隆升剥蚀、盆地热史等研究的典型案例分析,以期为裂变径迹应用的相关研究提供参考。The fission track technology has been applied to many geological applications with advantages of less sample consumption,lower closure temperature and wider dating range.For example,fully or partially annealed samples can effectively record the cooling-exhumation history and constrain the onset of thrust fault activity.The relationship between the weathering and denudation history of the overlying rocks and the preservation of the deposit can be used to quantify the amount of denudation and uplift in the deposit and to predict the mineralization.The fission track closure temperature of zircon is corresponding to the temperature interval of gas production,which can also be applied to oil and gas exploration studies.Recently,the combination of elemental content analysis with fission track techniques was also allowed for provenance analysis,and the implementation of LA-ICP-MS technology has brought the dawning for low U content mineral track measurements.The authors in this paper briefly summarize the results of fission annealing studies of apatite and zircon and the possible implications for data interpretation.The apatite annealing is affected by temperature,chemical composition,crystallographic anisotropy,and D_(par) value,while zircon track thermal stability is reduced mainly due to radiation damage effects.Laboratory annealing characterization provides an important theoretical reference for understanding the complex chemical dynamics of fission track annealing,but actual data interpretation must be combined with geological facts to obtain a clearer temporal framework for studying the evolution of geothermal events.The typical case studies of track dating on mineral deposits,mountain uplift denudation and basin thermal history were briefly analyzed in this paper,which would provide guidelines for relevant application studies of fission track.

关 键 词：裂变径迹 地质应用 地质热历史 地质热事件 

分 类 号：P597[天文地球—地球化学]