华南锑矿成矿带中方解石的铀铅年代测定

U-Pb Dating of Calcite from the South China Antimony Metallogenic Belt.

作者信息

Luo Kai, Zhou Jia-Xi, Feng Yue-Xing, Uysal I Tonguc, Nguyen Ai, Zhao Jian-Xin, Zhang Jiawei

机构信息

School of Earth Sciences, Yunnan University, Kunming 650500, China.

School of Earth and Environmental Sciences, the University of Queensland, Brisbane QLD 4072, Australia.

出版信息

iScience. 2020 Sep 18;23(10):101575. doi: 10.1016/j.isci.2020.101575. eCollection 2020 Oct 23.

DOI:10.1016/j.isci.2020.101575

PMID:33083741

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7530294/

Abstract

Accurately determining the age of hydrothermal ore deposits is difficult, because of lack of suitable mineral chronometers and techniques. Here we present the first LA-MC-ICPMS U-Pb age of carbonates from hydrothermal Sb deposits. Three stages of hydrothermal carbonates from the giant South China Sb metallogenic belt were identified: (1) pre-ore dolomite (Dol-I), (2) syn-ore calcite (Cal-II), and (3) post-ore calcite (Cal-III). The U and Pb isotopic data show that Cal-II yielded a lower intercept age of 115.3 ± 1.5 Ma (MSWD = 2.0), suggesting a Sb mineralization that corresponds to an extension event occurred during the early Cretaceous in South China. Although Cal-III yielded an age of 60.0 ± 0.9 Ma (MSWD = 1.5), indicating a potential tectonothermal event occurred in this belt during the early Cenozoic. Hence, U-Pb dating of calcite offers a new way to determine the age of hydrothermal ore deposits.

摘要

由于缺乏合适的矿物计时计和技术，准确确定热液矿床的年龄很困难。在此，我们展示了首个来自热液锑矿床碳酸盐的激光剥蚀多接收电感耦合等离子体质谱（LA-MC-ICPMS）铀铅年龄。识别出了来自巨大的华南锑成矿带热液碳酸盐的三个阶段：（1）成矿前白云石（Dol-I），（2）成矿期方解石（Cal-II），以及（3）成矿后方解石（Cal-III）。铀和铅同位素数据表明，Cal-II产生了较低的截距年龄115.3 ± 1.5百万年（加权均方偏差MSWD = 2.0），表明一次锑矿化作用对应于中国南方早白垩世发生的一次伸展事件。尽管Cal-III产生了60.0 ± 0.9百万年的年龄（MSWD = 1.5），表明该成矿带在早新生代发生了一次潜在的构造热事件。因此，方解石的铀铅定年为确定热液矿床的年龄提供了一种新方法。