灵武煤田延安组煤的煤岩煤质特征及地质解释

灵武煤田的中侏罗统延安组含煤岩系为一湖泊三角洲沉积。在稳定的大地构造条件和环境水介质条件的控制下，形成了富惰性组、特低灰－低灰、特低硫－中硫煤。上、下三角洲平原及过渡带的泥炭沼泽的煤岩煤质特征具有垂向和侧向分带性，彼此间又有差异。这种分带性系由沼泽位置、沼泽类型和植物类型造成。在延安组第三段沉积期发生的微咸水化引起了煤的硫分的增高。

The Characteristics of Petrography and Quality and Geological Interpretation of Coal of Yanan Formation in Lingwu Coalfield.

The middle Jurassic series Yanan Formation of in Lingwu coalfield is a lacustrine deltaic deposit.Under the control of stable tectonic setting and medium environment,the coal have been formed which are rich in inertinite group and contain especially low to low ash,especially low to middle sulphur.The features of petrography and quality of coal in three different parts of delta,owing to the change in the position and types of swanp and plant community,show vertical and lateral zonation and difference between each other,During the deposition of the third member of yanan formation became slightly salt and made sulphur content of Coal increased.