论文部分内容阅读
小层序（Ｐａｒａｓｅｑｕｅｎｃｅ）为Ⅲ级含煤层序的内部构成单元—体系域单元。研究表明，海陆交替型含煤层序可识别出稳定的能作为区域对比的周期性小层序，其顶底界面多为事件型海侵面和泥炭化事件界面。根据小层的成因特点和含煤情况，将小层序划分为：波浪作用为主形成的总体向上变细小层序、潮汐流作用为主形成的含煤小层序（有向上变细、向上变粗又变细两类）、河流作用为主受潮汐流影响形成的具有向上变粗又变细的二元结构的含煤小层序。小层序类型和小层序组的形成与内陆表海海平面变化特点具有十分密切的关系，海水的退却致使沉积体系进入废弃阶段而泥炭沼泽化，标志着小层序发育的终结。因此，研究小层序的形成与研究煤聚积规律具有密切关系。
Parasequence is the internal structural unit - system domain unit of Ⅲ coal rank. The results show that the alternating sequences of sea-land coal-bearing sequence can identify a stable small sequence that can be used as regional contrast, and the top and bottom interfaces are mostly event-type sea-surface and peat-type events. According to the genesis and characteristics of small layers and coal-bearing conditions, the small sequence is divided into the following sequence: the upward updip fine sequence formed by the wave action and the coal-rich sequence formed mainly by tidal flow Coarser and thinner), the coal-bearing small sequence with the upward coarsening and thinning binary structure formed by the influence of tidal flow. The formation of small sequence types and small sequence groups is closely related to the change of sea surface level in the inland sea surface. The retreat of seawater led the sedimentary system to the abandoned stage and the peat swamp, marking the end of small sequence development. Therefore, the study of the formation of small sequences is closely related to the study of coal accumulation law.