论文部分内容阅读
新疆塔里木盆地西北缘大湾沟剖面晚奥陶世地层发现保存良好的疑源类组合。该组合包括17属27种,以棘刺类(特别是Baltisphaeridium)占优势;其次为梭形类,以Navifusa为代表。大湾沟疑源类组合与世界其它地区同期组合对比表明,在晚奥陶世时疑源类古生物地理分区性减弱,不及早—中奥陶世明显。该组合中有13个种仅分布于“Caradoc”—“Ashgill”期,地理分布广泛,因而颇具生物地层学潜力。
A well-preserved collection of suspected sources has been found in the Late Ordovician strata at the Dawanggou Section in the northwestern margin of the Tarim Basin in Xinjiang. The assemblage includes 27 genera and 17 genera, which are dominated by spines (especially Baltisphaeridium), followed by fusiform (Navifusa). The comparison between the source class assemblages of Dawangou and the contemporaneous assemblages of other parts of the world shows that the Palaeogeography of the source rocks of the Late Ordovician period was weakened and not earlier than that of the Middle Ordovician. Thirteen species in this assemblage are distributed only in the “Caradoc” - “Ashgill” period and are widely distributed geographically and thus have potential for biostratigraphy.