投稿时间：2022-02-28
修订日期：2023-03-17
网络发布日期：2023-05-06
中文摘要:长汉沟石墨矿是华北克拉通西部孔兹岩带内新发现的石墨矿，虽然目前处于勘查的初始阶段，但已有的资料显示其深部与外围找矿潜力较大。文章通过对该石墨矿的2种典型矿石开展岩石地球化学研究，探讨其矿床成因和构造背景。长汉沟含石墨矿石w （Al2O3）（6.67%~14.28%，平均值11.52%）、w （K2O）（1.73%~6.09%，平均值3.33%）、w （CaO）（0.03%~1.60%，平均值0.96%），具有明显的富铝贫钙的特征。大离子亲石元素Rb、Sr、Cs等的含量偏低，w （Ba）相对富集（657.60×10-6~2036.00×10-6，平均值为1071.71×10-6）；Rb/Sr比值为0.47~1.68，平均值1.02；Sr/Ba比值为0.03~0.23，平均值0.11，Rb/Sr > Sr/Ba；稀土元素总量（∑REE）较高，w （REE）为44.94×10-6~382.18×10-6，平均值150.21×10-6，稀土元素配分曲线整体右倾，轻稀土元素明显富集，Eu在含石墨榴石黑云二长片麻岩和混合岩化含石墨黑云角闪斜长片麻岩中，分别显示出负Eu异常与正Eu异常的特征。通过综合研究分析，该石墨矿具有典型的孔兹岩带石墨矿特征，沉积于稳定-半稳定缺氧、滨浅海相的环境中，形成于陆缘弧后盆地，以有机质为主要的碳质来源，其后经区域变质作用逐步成矿，同时叠加了后期的混合岩化成矿作用，属区域变质型成因矿床。
Abstract:The Changhangou graphite deposit is a newly discovered graphite deposit in the North China Craton Khon-zite belt. At present, the surface of the ore body has been controlled by sparse trench exploration, and its deep and peripheral prospecting potential is great. In this paper, the geochemical characteristics of the two typical ores of this graphite deposit have been studied, and the tectonic background, depositional environment and genesis of the deposit have been discussed. The results show that the w(Al2O3) of Changhangou graphite is 6.67%~14.28%, with an average value of 11.52%; the w(Na2O) is 0.51%~1.78%, with an average value of 1.08%; the w(K2O) is 1.73%~6.09%, with an average value of 3.33%, with obvious characteristics of being rich in aluminum and poor in calcium; among the large ion lithophile elements, Rb, Sr and Cs are relatively depleted and low in content, and Ba element is relatively enriched, with a content value of 657.60×10-6~2036.00×10-6 and an average value of 1071.71×10-6, the Rb/Sr ratio of the sample is 0.47~1.68, the average value is 1.02; the Sr/Ba ratio is 0.03~0.23, the average value is 0.11, Rb/Sr > Sr/Ba; the total amount of rare earth elements in the sample (∑REE)is relatively high, ranging from 44.94×10-6 to 382.18×10-6, with an average value of 150.21×10-6. The rare earth element partition curve is slanted to the right as a whole, and light rare earths are obviously enriched, and the two typical ores show negative Eu anomalies and positive Eu anomalies are two different rare earth element characteristics. Through comprehensive research and analysis, this graphite deposit has the typical characteristics of graphite deposits in the Khonzite belt. It was deposited in a stable-semi-stable anoxic, littoral-neritic environment, and formed in a continental margin back-arc basin, with organic matter as the main carbonaceous material. It is a regional metamorphic genetic deposit.
keywords:geology crystalline graphite deposits geochemical characteristics genesis of deposits tectonic-sedimentary environment Hadamengou area
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基金项目:本文得到中国地质调查局项目（编号：DD20191017、DZ20220312、DD20230384）资助
引用文本：
杨彪,李成元,薄海军,侯秀宏,苏攀云,樊松浩.2023.内蒙古哈达门沟地区长汉沟晶质石墨矿床地球化学特征与成因研究[J].矿床地质,42(2):444~462YANG Biao,LI ChengYuan,BO HaiJun,HOU XiuHong,SU PanYun,FAN SongHao.2023.Geochemical characteristics and genesis of Changhangou crystalline graphite deposit in Hadamengou area, Inner Mongolia[J].Mineral Deposits42(2):444~462
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