| 鄂西、湘西北二叠纪(竹蜓)类的古地理分区及其意义 |
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| THE DIVISION OF PALEOGEOGRAPHIC AREAS OF PERMIAN FUSULINIDS IN WESTERN HUBEI AND NORTHWESTERN HUNAN AND THEIR SIGNIFICANCE |
| Permian fusulinid faunas in western Hubei and northwestern Hunan not only show distinct zoning in vertical section (see Table 1), but laterally there are also appreciable changes in fusulinid assemblages.It is particularly the case with the fusulinid fauna represented by the Neoschwagerina and Yabeina zones in the upper part of the Maokou Formation, which is regionally confined to a definite areal extent, designated by the author the Neoschwagerina-Yabeina ecotope (ecological group) (called the N-Y ecotope for short). The N-Y ecotope covers a northwest-trending narrow region approximately 10-15 km wide and 200 km in length from Maogang, Dayong, Hunan, to Shizhu, Sichuan. In this paper, the author expounds with concrete materials the ecological environment of the N-Y ecotope and the paleogeo-graphic features of this environment, and concludes that the N-Y ecotope was actually the main part of the coal-accumulating depression that had existed prior to the coal-accumulating stage between the Upper and Lower Permian in western Hubei and northwestern Hunan. Hence the N-Y ecotope and its surrounding areas should be considered to be the main direction of coalfield prediction and exploration in the region. After the coal-accumulating stage, the lateral distribution of the Late Permian fusulinid zones of Codonofusiella, Gallowayinella and Palaeofusulina sinensis (in ascending order) also had a definite areal extent, designated in this paper the Codonofusiella-Gallowayinella-Palaeofusulina sinensis ecotope (ecological group) (called the C-G-P ecotope for short) . The areal extent of the C-G-P ecotope inherited that of the N-Y ecotope under certain conditions, and both show roughly the same ecological environment and conditions; therefore the study of the areal extent of the C-G-P ecotope will also contribute to the study of the regularity governing the distribution of the coal-accumulating depression prior to its existence. |
| LIN Jia-xing.1985.THE DIVISION OF PALEOGEOGRAPHIC AREAS OF PERMIAN FUSULINIDS IN WESTERN HUBEI AND NORTHWESTERN HUNAN AND THEIR SIGNIFICANCE[J].Acta Geoscientica Sinica,7(1):103-112. |
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