甘肃靖远县宝积山晚三叠世植物群组合与含煤远景初探

THE LATE TRIASSIC FLORA AND COAL PROSPECTS AT BAOJISHAN,JINGYUAN, GANSU

摘要: 笔者对宝积山晚三叠世地层剖面、植物群组合的分析研究,认为有利于泥炭的形成,并对找煤工作提出建议。

Abstract: The fossil flora described in this paper occurs in the Upper Triassic Nanying’er Group in the vicinity of Longfengshan and Baojishan. Jingyuan County, Gansu Province. The flora includes two phyla, Pteridophyta and Gymnospermatophyta, and five classes, Articculatae, Filices, Pteridospermopsida, Ginkgopsida and coniferae. There are a total of 11 genera. According to the elements of the flora and its distribution features, three assemblages may be distinguished: Assemblage Ⅰ: Sphenopteris-Neocalamites, Carnian in age; Assemblage Ⅱ: Danaeopsis-Bernoullia, early and middle Norian in age; Assemblage III: Dictyphyllum-Podozamites, late Norian-Rhaetian in age. The late Norian-Rhaetian stage is an important coal-forming period in the area. The upper sector of the strata of this period, i.e. Beds 12-16, is a zone favourable for coal accumulation. The synclinal structure and paleofluvial areas provide good coal-forming conditions.