摘要
云南临沧是我国重要的Ge资源基地,大田河煤矿是近年来所发现的具有锗成矿条件的矿床。对矿区内主要出露的含锗煤、泥沙质细砾岩及黑云二长花岗岩稀土元素组成进行了系统研究和对比,结果表明,该矿床的稀土元素表现为LREE富集的右倾型,且负Eu异常明显,而Ce异常程度较弱。其中,含锗煤和泥沙质细砾岩与三叠世黑云二长花岗岩具有较一致的稀土元素标准化配分模式,且ΣREE和δEu等参数从黑云二长花岗岩→泥沙质细砾岩→含锗煤呈逐渐降低的趋势,此外,含锗煤在ΣREE-δEu和ΣREE-δCe关系图上显示与三叠世黑云二长花岗岩关系密切,而与矿区外围二叠世黑云母花岗岩关系较小。结合该矿床产出地质特征,本文认为含锗煤和泥沙质细砾岩可能继承了黑云二长花岗岩的稀土元素,矿床中Ge主要来自于三叠世黑云二长花岗岩,Ge的超常富集与三叠世岩浆侵入热液活动有关,并形成于相对还原的环境。
The Lincang area of Yunnan Province is an important district of germanium resource in China. The Datianhe coal mine was founded in recent years that it has good potential of germanium resources. A systematic comparative study on geochemical characteristics of rare earth elements of Ge-bearing coal,muddy and sandy fine conglomerate,and biotite monzongranite,which are mainly exposed in the Datianhe coalfield,has been carried out in this paper. The results show that REE distribution patterns of samples from the deposit are characterized with enriched LREE right-declined REE patterns,obvious negative Eu anomalies,and very weak Ce anomalies. Especially,REE patterns of the Ge-bearing coal and the muddy and sandy fine conglomerate are quite similar to those of the Triassic biotite monzongranite. The ΣREE contents and δEu values of samples are gradually reduced from biotite monzongranite,muddy and sandy fine conglomerate,to Ge-bearing coals. In addition,the Ge-bearing coals have a close relationship with Triassic biotite monzongranite,but very limited relationship with the adjacent Permian biotite granite in the ΣREE-δEu and ΣREE-δCe plots. Combining with the geological characteristics of the deposit,it is suggested that the REE of the Ge-bearing coals and the muddy and sandy fine conglomerate could be inherited from that of Triassic biotite monzonitic granite. The Ge of the Ge-bearing coals could be mainly derived from the Triassic monzonitic granite,enriched by the hydrothermal activity of the Triassic magma,and deposited in a relative reduced environment.
出处
《矿物学报》
CAS
CSCD
北大核心
2018年第3期313-320,共8页
Acta Mineralogica Sinica
关键词
大田河锗煤矿床
含锗煤
泥沙质细砾岩
黑云二长花岗岩
稀土元素
Datianhe Ge-bearing coalfield
Ge-bearing coal
muddy and sandy fine conglomerate
biotite monzonitic granite
Rare Earth Elements(REE)
