摘要
利用现代同位素年代学的技术方法,按照一定的比例尺和统一的技术要求,测定某一区域内地质体的同位素年龄,在地质图上清晰地表达相关地质体的时空分布格局,为深入研究区域地质演化规律和地质找矿工作提供依据,这是当前同位素年代学填图的主要工作。本次研究采用单颗粒锆石SHRIMP和LA-MC-ICPMS定年方法,尝试性地对南岭东段北部9个1∶20万图幅(井冈山幅、兴国幅、宁化幅、赣州幅、于都幅、长汀幅、龙南幅、寻乌幅和上杭幅)范围内代表性的上百个岩体样品进行了锆石U-Pb年代学研究,修正了原先由于缺少准确的年龄数据而误判的岩体时代,进而对各岩体的侵位时代进行了重新厘定,这对于深入研究该区域地质演化历史和成岩成矿规律具有重要的现实意义。本文也指出了同位素年代学填图工作中对样品布置采集、数据合理使用的基本要求以及综合分析在解释区域岩浆岩成因与地质演化方面的重要性。
The main objective of the geochronological mapping underway is, using modern geochronological technology, according to certain scale and unified technical requirements, determining the isotope ages of geologic bodies in a certain region, and expressing spatial and temporal distribution of geologic bodies in the geological maps clearly, and then providing the basis for further study of the regional geological evolution and metallogeny. In this paper, we present the progress of our tentative geochrological mapping of the igneous rocks in the northeastern part of the Nanling region, China. The study region includes nine map units in 1∶200000 scale （Jinggangshan, Xinggguo, Ninghua, Ganzhou, Yudu, Changting, Longnan, Xunwu and Shanghang）. Using SHRIMP and LA-MC-ICPMS methods, we conducted U-Pb dating on more than 2000 grains of zircons from about 100 typical intrusions in this region, revised many misjudged ages of the rock bodies and re-determined their emplacement age. This work has important practical significance on further study of geological evolution and metallogeny of the region. Meanwhile, we pointed out some basic requirements of sampling and reasonable using of the data in geochronological mapping work, and indicated the importance of comprehensive analysis of the petrogenesis of the regional magmatic rocks and geological evolution.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2014年第2期375-387,共13页
Geotectonica et Metallogenia
基金
国家深部探测专项“南岭成矿带地壳岩浆系统结构探测实验”课题(编号:Sinoprobe-03-01)
中国地质大调查“南岭岩浆岩成矿专属性”(编号:1212011120989)
“我国离子吸附型稀土战略调查及研究”项目(编号:1212011220804)
“中国矿产地质与区域成矿规律综合研究(中国矿产地质志)”项目(编号:1212011220369)”
公益性行业科研专项“南岭东段九龙脑矿田成矿规律与深部成矿预测综合研究”(编号:201411050-1)资助
关键词
南岭东段北部
岩浆岩
同位素年代学填图
地质演化规律
the northeastern section of the Nanling region
igneous rocks
geochronology mapping
geological evolution and metallogenic regularities
