Re-Os dating of galena and sphalerite from lead-zinc sulfide deposits in Yunnan Province, SW China
Re-Os dating of galena and sphalerite from lead-zinc sulfide deposits in Yunnan Province, SW China
复制标题
DOI：
10.1007/s12583-015-0539-6
复制
发表时间：
2015-06
影响因子：
3.3
通讯作者：
Yingying Liu;L. Qi;Jian-Feng Gao;L. Ye;Zhilong Huang;Jiaxi Zhou
中科院分区：
文献类型：
--
作者：
Yingying Liu;L. Qi;Jian-Feng Gao;L. Ye;Zhilong Huang;Jiaxi Zhou
铅锌矿的定年对于更好地了解矿石成因至关重要，但长期以来一直是一个巨大的挑战，因为缺乏合适的矿物，可以明确地与矿石成因联系起来，并可用于传统的辐射测量方法。该类矿床矿物学简单，以方铅矿、闪锌矿为主，常与方解石等脉石矿物伴生。方铅矿和闪锌矿的可变Re浓度分别为低和高，因此对这些矿物进行Re- os测年的前景不太乐观。此外，当采用常规方法时，方铅矿的Re回收率极低，这给方铅矿的精确测年增加了难度。在本研究中，我们研究了不同阴离子交换分离介质对稀土的回收，并报道了一种改进的方铅矿和闪锌矿Re- os定年的制备方法。利用该方法，获得了云南富乐（20.4±3.2 Ma）和老厂（308±25 Ma）铅锌矿方铅矿和闪锌矿的Re-Os等时线年龄。
Dating of lead-zinc deposits is of critical importance for better understanding of ore genesis, but has long been a big challenge due to the lack of suitable minerals that can be unequivocally linked to the ore genesis and that can be used for tradition radiometric methods. This kind of deposits have simple mineralogy dominated by galena and sphalerite commonly associated with calcite and other gangue minerals. Both galena and sphalerite have low and high variable Re concentrations and thus Re-Os dating of these minerals have been less promising. In addition, the recovery of Re is extremely low for galena when conventional method was applied, lending additional difficulty in precisely dating galena. In this study, we investigate the recovery of Re using different media for anion exchange separation and reporte a revised preparation method for Re-Os dating of galena and sphalerite. By using the new protocol, two reliable Re-Os isochron ages of galena and sphalerite from the Fule (20.4±3.2 Ma) and Laochang (308±25 Ma) Pb-Zn deposits in Yunnan Province, SW China, are achieved.