论文部分内容阅读
本文研究了辽西北票四合屯脊椎动物化石产地附近土城子组三段的孢粉组合,共计32属9种及25未定种。孢粉组合以松柏类两气囊花粉占绝对优势,三缝孢子含量低。当前组合中见有Cicatricosisporites,Lygodioisporites,Jiaohepollis,Rugubivesiculites等早白垩世特征分子,同时未见被子植物花粉,推测其时代为早白垩世早期,这与同位素测年结果相一致。这一孢粉组合以松柏类两气囊花粉的高含量及Classopollis的低含量为特征,明显不同于以往报道的土城子组的孢粉组合,却与辽西地区义县组下部层段的孢粉组合非常相似,表明辽西地区土城子组沉积的末期区域植物群面貌与义县组已无本质差别,尽管两套地层在岩相和沉积上差异明显。这一发现提示我们,土城子组的横向对比对于正确重建中国北方侏罗纪—白垩纪早期的沉积演化史十分关键,有必要在后续研究中进一步开展其他地区土城子组的孢粉等生物地层及区域间的对比工作。
In this paper, the spore-pollen assemblage of the third member of Tuchengzi Formation near the origin of the Sihetun vertebrate fossils in Sihetun, Liaoning Province is studied. There are 9 genera and 9 species of 25 genera and 25 undetermined species in 32 genera. Spore-pollen combination of conch class two balloon pollen absolute advantage, three stitches low spore content. In the current assemblage, there are early Cretaceous characteristic molecules such as Cicatricosisporites, Lygodioisporites, Jiaohepollis and Rugubivesiculites, and no pollen of angiosperms is found. It is presumed that the age is early Early Cretaceous, which is consistent with the dating results of isotopes. The spore-pollen assemblage is characterized by the high content of coniferous-type two-balloon pollen and the low content of Classopollis, which is obviously different from the previously reported spore-pollen assemblage in Tuchengzi Formation and spore-pollen assemblage in the lower part of Yixian Formation in western Liaoning Are very similar, indicating that there is no essential difference between the fauna and the Yixian Formation in the late stage of Tuchengzi Formation in western Liaoning, although the two sets of strata differ greatly in lithofacies and sediments. This finding prompts us that the horizontal contrast of Tuchengzi Formation is crucial to the correct reconstruction of Jurassic-Cretaceous depositional evolution in the northern part of China. It is necessary to further develop the biogenic strata of the Tuchengzi Formation in other areas in subsequent studies And the contrast between regions.