地质调查与研究2016，Vol.39Issue(3)：161-168,8.
内蒙古赤峰市白音诺尔铅锌矿二长花岗岩地球化学及锆石 U-Pb 年代学研究
Zircon LA-ICP-MS U-Pb ages and geochemical characteristics of monzonitic granite from Baiyinnuoer Pb-Zn deposit, Chifeng city, Inner Mongolia
摘要
Abstract
The Baiyinnuoer ore deposit in Inner Mongolia is the largest Pb-Zn deposit in Da Hinggan Mountains metallogenic belt. It located in the northern part of Baiyinwula volcanic agencies, Pb-Zn orebodies mainly occur along the contact zone between the gradiorite and the carbonate rock. The authors dated the zircons of two sam-ples from the granodiorites using the LA-MC-ICP-MS method. Two reliable weighted mean 206Pb/238U ages are (254.8±1.6)Ma(MSWD=3.0,n=29)and(245.6±3.5)Ma(MSWD=5.9,n=13). Lead-zinc mineralization was spa-tio-temporal correlation with granodiorites, suggesting that Baiyinnuoer Lead-zinc Deposit was the product of late Hercynian to early Indosinian tectonic magmatic activity. The granodiorites have a SiO2 range of 68.98 to 75.44wt%,with relatively high Al2O3 (15.52%~15.26 wt%) and low MaO (0.1~1.25wt%) content, and charac-terized by extremely rich alkali(Na2O=4.04%~4.36%,K2O=3.98%~4.05wt%,Na2O+K2O=7.73%~8.80wt%, Na2O/ K2O=0.96~1.33). All samples fall into the high K calk-alkali series region and have metaluminous charac-teristics. The distribution of REE characterized by enrichment in LREE, and total amount of rare earth varied from 127.4~145.95 ppm. The REE are weak positive Ce anomalies (δCe=1.11~1.34) and significant negative Eu anomalies (δEu=0.08~0.58), trace elements characterized enrichment Rb, Th, K, LILE, loss Nb, Ta, P, Ti and other high field strength element (HFSE). In the Rb- (Y+Nb) and Rb- (Yb+Ta) tectonic environment discrimina-tion diagrams, all samples fall into the tectonic setting of volcanic arc, suggesting that local remnant basin subduc-tion in the late stage of the Late Paleozoic to Early Indosinian formed the high-K calc alkaline and metaluminous granodiorite in Baiyinnuoer.关键词
铅锌矿床/二长花岗岩/锆石U-Pb年代学/岩石地球化学/白音诺尔/内蒙古Key words
Pb-Zn deposit/monzonitic granite/Zircon LA-ICP-MS U-Pb ages/geochemical characteristics/Baiyinnuoer/Inner Mongolia分类
地质学引用本文复制引用
段明,李志丹,王国明,高智睿,张锋,魏佳林,谢瑜,闫国强..内蒙古赤峰市白音诺尔铅锌矿二长花岗岩地球化学及锆石 U-Pb 年代学研究[J].地质调查与研究,2016,39(3):161-168,8.基金项目
中国地质调查项目“内蒙古锡林浩特地区1/5万航磁异常筛选与评价12120113057100，阴山地区成矿规律与找矿方向研究12120113057300）”联合资助 （）
