The lower part of the Upper Carboniferous Series is called Sixiakou Formation whose definition differ.

上石炭统下部称泗峡口组，重新定义了泗峡口组的含义。

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The Lower Carboniferous Ceshui and Upper Permian Longtan coal series are most important in Southeast China, and can both generate and bear gas greatly in the Lianyuan coal basin, Central Hunan, China.

湘中涟源煤盆地早石炭世测水组、晚二叠世龙潭组煤系是中国东南诸省境内最重要的煤系，具有较大的生气、储气能力。

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