摘要
青海省三叠纪地层发育、分布很广,占全省总面积的二分之一以上.原认为三叠纪地层以中、上三叠统为主,根据孢粉研究资料显示的特征修正为以下三叠统(包括部分原订为二叠纪的地层)为主,中、上三叠统次之或断续分布.首次对青海省的早三叠世孢子花粉组合,按地层分区进行了全面的归纳整理,识别出了5个地层群或组的9个孢粉组合,并讨论了其地层意义及对比等问题.华北区以下环仓组及赛尔贡切组组合为代表,分别以Lundbladispora或Aratrisporites的高含量为特征,并与少量Micrh ystridium共生;过渡区以洪水川组的组合为代表,以Taeniae porites及/或Limatulas porites/ Tubermonocol pites的高含量为特征,并与少量Micrh ystridium,Baltisphaeridium共存;华南区以下巴颜喀拉山群及池塘群组合为代表,以Lundbladispora较高含量为特征,并与Veryhachium 为主的疑源类共存.同时讨论了孢粉的地层意义及对比等问题,建议将原布青山群划入下巴颜喀拉山群.
Abstract
Triassic strata are well developed and widely distributed in Qinghai,occupying more than one half of the area of the province.The present paper attempts for the first time to give a synthesized and comprehensive analysis of the palynology of the Early Triassic strata in Qinghai.The Triassic strata were considered to be dominated by Middle-Upper Triassic sediments.However,more recent palynological studies have demonstrated that those strata are actually mainly of Early Triassic in age,while the Mid-Up-per Series of Triassic is subordinate or intermittent in distribution.The paper discusses problems related to the Early Triassic stratigraphic subdivision and correlation.Nine spore-pollen assemblages from 5 groups or formations are recognized.In short,the assemblages from the Lower Huancanggou and Sairgongqie formations in North China Area are characterized by the high content of Lundbladispora and Aratrisporites,respectively,in association with a few Micrhystridium.The transitional Area (belt) is represented by the assemblage of the Hongshuichuan Formation,and characterized by high content of Taeniaesporites and/or Limatulasporites/Tubermonocolpites.And the assemblages from the lower Bayanharshan and Chitang groups in South China are characterized by the high content of Lundbladispora in association with some acritarchs such as Veryhachium.
基金项目
中国科学院青年创新促进会,中国科学院战略先导专项(B)(XDB03010103)
国家自然科学基金(41530103)
国家自然科学基金(41530101)
国家自然科学基金(41372001)
NETL
NSTL
维普
万方数据