湘西北和鄂西云台观组孢子组合及其地层意义

通过对孢子组合的研究,确定云台观组属中泥盆统(季维特阶)。该地层不仅产出有丰富并保存完好的孢子,而且还有一些疑原类、虫颚和几丁虫碎片。文中描述的孢子包括19个属、30个种和变种,其中新种2个、新联合种1个,即小刺凸刺弓形脊三缝孢、多刺冠环三缝孢以及大刺剑刺三缝孢(新联合)。与北半球同类组合对比表明:湘西北和鄂西云台观组孢子组合主要为季维特阶的属种,从整个组合特征看,可能属晚季维特阶。文中还讨论了云台观组的沉积环境和地层意义。

THE MIOSPORE ASSEMBLAGE FROM YUNTAIGUAN FORMATION IN NORTHWESTERN HUNAN AND WESTERN HUBEI AND ITS STRATIGRAFICAL SIGNIFICANCE

The age of the Yuntaiguan Formation is reassessed and confirmed as Middle Devonia (Gevitian) based on the investigation of spore assemblages. It consists of not only abundant and well-pre-served spores, but also some Acritarchs, Scolecodonts and ? Chitinozorns. 19 genera, 30 species and varieties are presented, in which there are 2 new species and 1 new combination,i.e., Apiculiretusispora microspinosa, Cristatispoirtes multispinosus and Acinosporites grandis(Chibrikova)Gao(comb.nov.). The comparison with similar assemblages from northern Hemisphere indicates a Givetian age for Yuntaiguan Formation in NW.Hunan and W.Hubei. As the overall character of the whole asemblages is considered, it may belong to Late Givetian. The sedimentary enviroment of Yuntaiguan Formation and its stratigraphical significance are discussed.