摘要
滇东南富宁地区位于“滇黔桂金三角”南部,大地构造位置处于古特提斯构造域与环太平洋构造域的复合部位,区内基性岩浆活动发育,分布着一系列以基性岩为容矿岩石的金矿床(点)。本文对区内毛姐山金矿矿区基性侵入岩研究后发现:侵入岩主要成分为辉石和斜长石,岩性为辉长岩、辉长辉绿岩和辉绿辉长岩;岩石主量元素SiO_(2)含量为41.42%~46.3%,K_(2)O+Na_(2)O含量为2.61%~4.33%,TiO_(2)含量为1.93%~5.75%,为高钛、相对低SiO_(2)、相对富集Fe2O3的高钾钙碱性碱性岩系列基性岩;岩石稀土配分模式为右倾、轻稀土LREE富集;微量元素表明岩石Nb相对弱亏损、Ta富集,并且具有正Eu异常的特征。结合区域基性岩年代学及地球化学研究成果,认为基性侵入岩成岩时代可能为258~241 Ma,形成于伸展的大陆板内构造背景,其成岩时代与金矿化时代相差较大,对金成矿的贡献较小。
The Funing area in the southeast of Yunnan is located in the southern part of the"Yunnan-Guizhou-Guangxi Golden Triangle".It is situated at the junction of the ancient Tethys tectonic domain and the circum-Pacific tectonic domain.Within the region,there is developed basic magmatic activity,and a series of gold deposits(points)are distributed,with basic rocks serving as the host rocks for the ores.After studying the basic intrusive rocks in the Maojie Mountain gold mine area,it was found that the main components of the intrusive rocks are pyroxene and plagioclase,with the rock types being gabbro,norite,and monzogabbro.The major elements indicate that the rocks have a SiO_(2)content of 41.42%to 46.3%,a K_(2)O+Na_(2)O content of 2.61%to 4.33%,and a TiO_(2)content of 1.93%to 5.75%,classifying them as high-titanium,relatively low-SiO_(2),and relatively enriched in Fe_(2)O_(3),high-potassium calc-alkaline series of basic rocks.The rare earth element(REE)distribution pattern of the rocks is right-skewed,with an enrichment of light rare earth elements(LREE).Trace elements show that the rocks are relatively deficient in Nb,enriched in Ta,and have a positive Eu anomaly.Combining the regional basic rock geochronological and geochemical research results,it is believed that the crystallization age of the basic intrusive rocks may be 258-241 Ma,formed in the tectonic setting of an extended continental plate,with a significant difference in timing from the gold mineralization age,suggesting a minimal correlation with the gold mineralization process.
作者
薛伟
沈忠义
郭玉乾
孙玉海
折士焜
帅磊
XUE Wei;SHEN Zhongyi;GUO Yuqian;SUN Yuhai;SHE Shikun;SHUAI Lei(China Non-ferrous Metals Resource Geological Survey,Beijing 100012,China;Kunming Institute of Exploration and Design,China Nonferrous Industry,Kunming 650051,Yunnan,China)
出处
《矿产勘查》
2025年第8期1908-1917,共10页
Mineral Exploration
基金
云南省富宁县毛姐山金矿控矿因素与找矿方向研究项目资助。
关键词
基性侵入岩
地球化学特征
富宁地区
金矿床
mafic intrusive rock
geochemical characteristics
Funing area
gold deposit
