湖南省常宁市茶潦锰矿床地质特征及成因探讨

茶潦锰矿位于塔山岩体北侧外接触带,锰矿层呈层状顺层产于晚奥陶世天马山组一段(O3tm1)中,严格受地层控制。目前矿区已发现两个近于平行的锰矿层,其走向延伸超过3 km,倾向延伸超过200 m。含锰岩系岩性主要为灰色中-薄层状板岩夹浅变质杂砂岩,或板岩与浅变质杂砂岩互层,在岩相古地理上代表次深海近源陆屑浊积盆地亚相。矿石按自然类型属原生氧化锰矿石,主要矿石矿物有褐锰矿、软锰矿和水锰矿。矿石结构主要有他形晶结构、隐晶质结构、交代结构。矿石构造主要有块状构造、条带状构造。野外观察和综合研究获得的证据表明,该矿床为沉积变质型锰矿床。

Geological Characteristics and Genesis of Chaliao Manganese Deposit in Changning County,Hunan Province

Chaliao manganese deposit is located in the outer contact zone at the north side of Tashan intrusion. The manganese ore-bodies occur in the First Member of Tianmashan Formation of Later Ordovician with a layered form, and are strictly controlled by the strata. Currently two nearly parallel manganese layers have been found, which extend over 3 km at its strike and over 200 m at its inclination. Manganese-containing rock series are gray Medium-thin-bedded slate sandwiched with slightly metamorphic greywacke, or slate interbedded with slightly metamorphic greywacke, which represent bathyal continent scraps turbiditic subphase in terms of lithofacies and paleogeography. The ore of the deposit is native oxide manganese ore according to the natural type. The main ore minerals are braunite, pyrolusite and manganite. The main ore textures are shaped crystal texture, aphanitic texture and metasomatic texture. The main ore structures are massive structure, and banded structure. Evidences obtained from field observations and comprehensive study indicated that the deposit is a sedimentary-metamorphic manganese deposit.