近年,在滇东南中三叠统法郎组中先后发现老乌(东矿段)、梭落底、斗果等沉积型高硅锰矿(有别于该区其他锰矿床)。为了探寻该类型锰矿的工业利用途径,指导今后的普查与勘探,笔者对老乌锰矿(东矿段)进行了较深入的研究,现将研究成果介绍于下,以期交流。欠妥之处,敬望指正。 (一)含矿层位锰矿赋存于中三叠统法郎组碎屑岩中(表1)。法郎组含矿段第二亚段(T_2f_5~2自上而下为(图1): 上矿层(Vb) 含锰碳酸盐岩。表生氧化后成黑紫、紫红色氧化锰矿,地表平均含锰26.55％。具鲕、豆、结核状结构,斑状或块状构造,疏松多孔,体轻质差。厚0.39米。含锰泥质粉砂岩灰褐、褐黄色。上部0.65米显极薄的页片状微细层理,具密集的“麻点状”锰质点(图2),风化后呈薄板状脱落。厚4.11米。 In recent years, sedimentary-type high-manganese silicas (different from other manganese deposits in the area) have been found in the Middle Triassic Fraser Formation in Southeast Yunnan. In order to explore the industrial use of this type of manganese ore to guide the future census and exploration, the author conducted a more in-depth study of the old wuanguan (East Mine), the research results are introduced below, with a view to exchange. Imperfections, look up and correct. (I) Ore-bearing manganese ore occurs in the Middle Triassic Franc group clastic rocks (Table 1). The second sub-section of the FF-bearing ore-bearing section (T_2f_5 ~ 2) is from top to bottom (Figure 1): manganese-bearing carbonate rocks of the upper ore bed (Vb) Containing manganese 26.55%. With oolong, beans, nodular structure, patchy or massive structure, loose porous, lightweight body 0.39 meters thick. Manganese-rich siltstone gray brown, brown yellow. The top 0.65 m was extremely thin Of the sheet finely layered, with dense “pitting” manganese particles (Figure 2), weathered sheet was shedding, thickness 4.11 meters.