涟邵煤田北段测水煤系岩相古地理与聚煤作用

测水组是湘中早石炭世主要的含煤地层。该区早石炭世的海侵主要来自西南侧,物源主要来自东北方向的雪峰古隆起。测水早期沉积物有煤、泥岩、砂质泥岩及细砂岩,沉积环境为潟湖相、泥炭沼泽相、潮坪相及滨海相;晚期主要沉积了细-粗粒石英砂岩、砂质泥岩、泥岩及石灰岩,沉积环境有滨外泥质陆棚、滨外碳酸盐陆棚及滨海相。煤层主要形成于潟湖淤浅而成的泥炭沼泽环境,含煤性与煤系厚度、砂岩含量及砂泥比值等有一定相关性,富煤带只存在于一定厚度的含煤地层分布区。本区于早石炭世时期形成了西部金竹山和东部太平寺二个聚煤中心,其中西部含煤性及煤层稳定程度比东部好,是勘查找煤的重要地区。

Ceshui Formation Lithofacies Paleogeography and Coal Accumulation in Northern Section of Lianyuan-Shaoyang Coalfield,Central Hunan

The Early Carboniferous Ceshui Formation is the main coal-bearing strata in central Hunan. During the deposition of Ceshui Formation, marine transgression came from southwest, and the provenance was the Xuefeng old land. The Lower Member of the Ceshui Formation is composed of mudstone, sandy mudstone, fine sandstone and coal, indicating lagoon, peat swamp, tidal fiat and littoral facies. The Upper Member of Ceshui Formation is fine to coarse grained quartzite, sandy mudstone, mudstone and limestone, demonstrating an offshore muddy and carbonate shelf facies. The coal was deposited in the peat swamp developed from filled lagoon environment. Coal abundance has certain relationship with coal measures thickness, sandstone percentage, and sandstone/mudstones ratio. Coal abundance and stability showed a special variation, with the two coal accumulation centers being better than the surrounding areas, and the western area being better than the eastern area. Therefore, the Jinzhushan coal coalaccumulation center is the major target for coal exploration.