摘要
本文首次对青海南部结扎群中部碳酸盐岩组微古植物群进行了研究。该岩组所含孢粉组合以丰富的孢子花粉和形态多样的疑源类化石为特征,计62属91种。孢子花粉20属31种,疑源类42属60种,其中2个近似种,1个亲近种,10个相似种,5种类型植物碎片未定种。此外,还有4种分类位置不明的类型。地质时代为晚三叠世中期(T_3~2)。结扎群中部碳酸盐岩组,为一套浅海相沉积地层,沉积环境稳定。当时这一地区处于古地中海之滨或靠近环太平洋地槽。根据结扎群中存在丰富的蕨类植物面貌来看,当时的气候环境比较湿热或亚热带海洋性气候。
The micropaleoflora from the Middle Carbonate Rock Formation of Jiezha Group has been firstly studied in this paper.The abundance sporopollen and variform acritarch characteriz- ing the formation contain 62 genera and 91 species,in which 20 gen.and 31 sp.belong to sporopollen,42 gen.and 60 sp.acritarch.Among them one is affinis,twelve conformis and five species,in addition,four species indeterminata.The sporopollen assemblage is consisted of the dominant gymnospermous pollen of 49.0% in the amount,spore 18.8% and acritarch 32.2%.In detail,the spore is mainly made from Punctatisporites,Apiculatisporis,Marattis- porites,the pollen Pinaceae,Ovalipollis,Cycadopites and a few Chordasporites,Taeniaesporites, the acritarch Hystrichosphaeridium,Micrhystridium,Favososphaeridium,besides Leiofusa Qua- dratimorpha,Scolecodonts,Taenitum,Lignum and so on.The geological time is middle upper Triassic. The Carbonate Rock Formation is composed of a suite of the epicontinental sedimentary strata being 1303 m thickness and formed in the stably olepositional enviroment.The region should,then,lie in the shore of Paleomediterranean sea or near the geosyncline round the Pacific.Based on the abundance gymnospermous spore fron Jiezha Group,the climate at that time should be humid torrid or subtorrid zone marine.
关键词
微古材群
上三叠统
青海
结扎群
Upper Triassic
Middle carbonate rock formation of Jiezha Group
Micropaleoflora
