The upper Serpukhovian Poruba Member (c. 325–324 Ma) is a coal-bearing “paralic” succession deposited in the Upper Silesian Coal Basin located along the eastern foreland of the Moravo-Silesian segment of the Variscan fold and thrust belt. The basin formed an >150 km long, tectonically controlled embayment open to the north and northeast, with estuarine circulation, predominance of fluvial discharge and a limited tidal influence. A high-accommodation depocentre (possibly up to 1100 m/Myr) was filled by shallowing-upward successions related to the progradation of river dominated (bay-head) deltas, with subordinate fluvial and marine sediments. These strata form two orders of transgressive-regressive cycles, or genetic sequences, both overlapping with the Milankovitch band. Intervals of maximum transgression, marked by marine or brackish faunal horizons, immediately overlie coal beds, suggesting non-accretionary transgression in a low energy setting. Six medium-term genetic sequences (cyclothems) are recognized, each consisting of 4 to 6 elementary sequences and a number of smaller scale units of possible autocyclic origin. The medium-term sequences are attributed to a combined influence of relative sea-level change and changes in sediment input, both possibly as a far field response to Gondwanan glaciation through glacioeustasy and attendant changes in climatic seasonality.

中文翻译：

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上西里西亚前陆上密西西比统含煤副旋回层的沉积背景和层序地层

上Serpukhovian Poruba 段（约325-324 Ma）是沉积在上西里西亚煤盆地的含煤“平行”序列，位于瓦里西亚褶皱和冲断带摩拉沃-西里西亚段的东部前陆。该盆地形成了一个长超过150公里的受构造控制的海湾，向北部和东北部开放，具有河口环流，以河流流量为主，潮汐影响有限。一个高容留沉积中心（可能高达 1100 m/Myr）被与河流主导（湾头）三角洲的进积有关的浅层向上序列所填充，并伴有河流和海洋沉积物。这些地层形成了海侵-海退循环的两个阶次，或基因序列，均与米兰科维奇带重叠。以海洋或微咸动物层为标志的最大海侵区间直接覆盖煤层，表明低能量环境下的非增生海侵。识别了六个中期遗传序列（循环序列），每个序列由 4 到 6 个基本序列和许多可能的自循环起源的较小规模单元组成。中期序列归因于相对海平面变化和沉积物输入变化的综合影响，两者都可能是通过冰川平衡和随之而来的气候季节性变化对冈瓦纳冰川作用的远场响应。