织纳煤田龙潭组煤的岩浆热变质成因  

Magma thermal metamorphism of the Longtan formation coals in Zhina coalfield,Guizhou

作　　者：陈义林[1,2] 秦勇[1,2] 李壮福[1,2] 常会珍[1,2] 罗政[3] 

机构地区：[1]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221008 [2]中国矿业大学资源与地球科学学院,江苏徐州221116 [3]贵州省煤田地质局实验室,贵州贵阳550008

出　　处：《中国矿业大学学报》2012年第3期406-414,共9页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(40730422);国家重大科技专项(2011ZX05034-04)

摘　　要：贵州省中北部龙潭组煤的变质成因和"黔中隆起"构造具有特定的关系.分析了区域热液发育的背景条件,发现区内织纳煤田的煤级呈环状展布以及镜质组反射率梯度极其异常,结合阿弓向斜个别钻孔二氧化碳浓度异常及区域重力异常特征,认为"穹窿不均一"的岩浆热变质可能是贵州中北部煤级增高的主要原因.煤变质程度明显受龙潭组与可能的隐伏岩浆岩距离远近的影响,织纳煤田由于龙潭组下伏地层抬升剥蚀程度最大,利于向上传递岩浆热,导致煤级增高,反射率梯度值达到0.3%～0.4%/100m.There is a specific relationship between the metamorphism of the Longtan formation coals and the Qianzhong uplift in central-northern Guizhou including the Zhina coalfield. Based on the analysis to the previous information on regional hydrothermal activity, the annular oc- currrence of coal rank and the abnormal vitri＇nite reflectance gradient in Zhina are found. It is suggested that the increase of the coal rank in Zhina might be resulted mianly from the uneven magma thermal metamorphism of the Qianzhong uplift combined with the higher carbon dioxide concentration in individual drillings of the Agong syncline and the regional gravity anomaly. Coalification degeree is evidently affected by the distance between the insidious magmatites and Longtan formation. Strata under the Longtan formation in Zhina was severely eroded, which was in favor of the upward conductivity of the heat flow. This might be why the higher coal rank and abnormal reflectance gradient of 0. 3%-0.4%/100m occur in the Zhina coalfield.

关 键 词：织纳煤田 隐伏岩浆岩 龙潭组 热变质作用 

分 类 号：P618[天文地球—矿床学]