淮南煤田二叠系三、四含煤段古水系特征

Paleodrainage Characteristics of the Permian Members C and D in Huainan Coalfield, China

本文通过对淮南煤田二叠系三、四含煤段5千余个钻孔资料的系统分析和煤矿开拓巷道中古流向的实际测量,获得大量有关古水系的第一性资料。研究认为可与现代珠江三角洲上的水系进行类比、进而推断三、四含煤段沉积时的环境为一种由多条陆源河流共同作用形成的复合型三角洲。

The Huainan Coalfield, covering an area of more than 8000 km2. is concealed by the Quaternary system, and the main coal-bearing strata are Permian Members C-D. By the investigation of more than 5000 bores and surveying of undergroud tunnels of the coal mines in the research district, many characteristics of the paleodrainage have been acquired as follows: 1. By undergroud surveying of the main channel sandstones of the members C-D, it is shown that during their deposition the paleocurrent direction is southward. Z.The paleodrainage of the Permian members C-D have two forms, the branched channel system (in member C) and the anastomosing channel system (in member D). The channels composed the drainages are very stable and fail to lateral migration. 3. The results of grainsize analysis and the C-M pattern of the same genetic increment demonstrates that the paleostream flown from north to south, and the south side is more near to the sea. 4. The characteristics of sedimentology and sedimentary geochemistry indicate that the fine sediments of member C which deposited in the branched channel system contain much more of the tidal sediments, burrows, and Lingula sp. etc. The content of the trace element B. B/ Ga and Ca/ (Fe+Ca) are higher than that of member D. To sum up the characteristics discussed above and analyze by means of Walther's Law of correlation of facies. and compare with the drainage on the modern Pearl River, the authers propose that the paleodrainage of the members C-D is more similar to that on the modern Pearl River Delta, that is to say, it can be divided into two parts, the anastomosing fluvial system near the continent and the branched fluvial system close to the sea. It is recognized that the paleodrainage discussed in this paper is different from that on the Mississippi River Delta and / or on the Yangtze River Delta, that could he account for which discussed in this paper is a complex delta formed together by several continental streams, the low-medium t rupge and the Coriolis force exist in the historv of the Earth.