安徽贵池地区二叠纪孤峰组含锰岩系稳定同位素特征  

Stable isotope characteristics of the manganese-bearing rock series of the Permian Gufeng Formation in the Guichi area,Anhui,China

作　　者：许卫[1,2] 岳书仓[3] 杜建国[1] 吴礼彬[1] 孙乘云[1] 王有生[1] 陶启云[1] 

机构地区：[1]安徽省地质调查院 [2].合肥工业大学资源与环境科学系,安徽合肥230009 [3]合肥工业大学资源与环境科学系

出　　处：《地质通报》2005年第8期778-782,共5页Geological Bulletin of China

基　　金：国土资源调查项目<安徽贵池地区富锰矿区域资源评价>资助。

摘　　要：安徽贵池地区沉积锰矿床赋存于二叠纪孤峰组。该矿床包括沉积作用形成的碳酸锰矿和经后期氧化作用形成的氧化锰矿。稳定同位素分析表明,含锰岩系的O、C稳定同位素具有较大的变化范围,δ13C为-4.1‰～5.0‰,δ18O为-3.40‰～-21.40‰,古温度普遍偏高,一般在50～65℃之间,说明其时沉积水体较深,古盐度分析结果(Z=124～133)显示均为正常海相沉积,氧化环境下氧同位素分馏作用表明形成氧化锰矿需要大量的大气降水。Sedimentary manganese deposits in the Guichi area, Anhui, occur in the Permian Gufeng Formation. They include manganese carbonate deposits formed by sedimentation and manganese oxide deposits formed by late-stage oxidation. Stable isotope analysis indicates that the carbon and oxygen stable isotope values in the manganese-bearing rock series have wide ranges,with δ^13C=-4.1-5‰ and δ^13O=-3.4-21.40‰. The paleotemperatures were commonly higher than normal, generally ranging from about 50 to 65℃, suggesting that the ore was deposited in relatively deep water bodies, and paleosalinity （Z=124-133）analysis indicates normal marine sedimentation. Oxygen isotope fractionation in an oxidizing environment indicates that large amount of water is needed for the formation of manganese oxide deposits.

关 键 词：含锰岩系 孤峰组 稳定同位素 安徽贵池地区 

分 类 号：P534.46[天文地球—古生物学与地层学] P597.2[天文地球—地质学]