摘要
本文首次报道在滇西施甸向阳寺剖面晚志留世-早泥盆世地层中发现孢子和疑源类,根据孢子特征及其在地层中的分布和演化规律,自下而上可划分出3个孢子带:1.Apiculiretusisporaspicula-Emphanisporitesneglectus(SN)带;2.Synorisporitesverrucatrs-Streelispora(VN)带;3.Breconisporitesbreconensis-Cymbosporitesdittonensi(BD)带。滇西施甸晚志留世-早泥盆世孢子带可与滇东曲靖和新回酉准噶尔同时代孢子带比较;亦可与西欧、北美有关孢子带比较。
Palynomorphs are recovered for the first time from the lute Silurian Niushiping Formation,Early Devonian Xianyangshi Formation and Wangjiacun Formation of Shidian County,West Yunnan. Spotes are diverse and include 19 form genera, 50 species and variaties, Acritarchs 9 genera, 15 species.As a result of the extensive studies of spores from the Late Silurian and Early Devonian in Shidian,West Yunnan,it may be subdivided into three spore zonations,one zone for the Late Silurian and two zones for the Early Devonian in ascending order as follows: 1. Apiculiretrsispora spicula Emphanisporites neglectus(SN) zone, 2. Synorisporites verrucatus-Streelispora newportensis(VN) zone,3. Breconisporites breconensis-Cymbosporites dittonensis (BD) zone.The wide geographical spread of the zones,especially those in the Late Silurian and Early Devonian,testifies to the apparently near cosmopolitan distribution of at least some components of vegetation that produced the spores. The spore zonations of the lute Silurian and Early Devonian of Shidian,West Yunnan, may be correlated with those of Qujing, East Yunnan, West Junggar, Xinjiang, China, Western Europe and other area of world. Based on the pelynological,the boundary of Silurian and Devonian,the reconstruction of Paleogeography and P8leoecology are discussed.