摘要
首次对研究区额木尔河群的古植物群进行了系统分析与研究。古植物群的组成主要为蕨类植物与裸子植物,其中蕨类植物主要包括真蕨植物门与楔叶植物门,共计8属15种;裸子植物包括银杏植物门、苏铁植物门及松柏植物门,共计15属29种,并阐述了各植物门的主要组成特征。额木尔河群的植物化石组合具有以下特征:(1)Coniopteris的分异度和丰度均较高;(2)产有中侏罗世较为典型分子Coniopteris burejensis与Eboracia lobifolia;(3)Coniopteris、Cladophlebis、Eboracia的共同大量出现为本区古植物群的主要特征。上述特征表明,该古植物群应该划归到Coniopteris-Phoenicopsis植物群的晚期组合,其时代为中侏罗世。通过对研究区额木尔河群古植物群在纵向上的分布以及植物化石组合特征的综合分析,将Coniopteris-Phoenicopsis植物群晚期组合进一步划分为3个亚组合,即绣峰组中的Coniopteris-Nilssonia亚组合、二十二站组中的Coniopteris-Czekanowskia亚组合、漠河组—开库康组中的Coniopteris burejensis-Cladophlebis cf.asiatica亚组合。本研究不仅丰富了研究区生物地层资料,确定额木尔河群的地质时代,更重要的是解决了目前研究区天然气水合物勘探的基础地质问题。
It is the very first time to analyze and study the paleoflora of Emuerhe Group in the research area systematically and describe the major component characteristics of each plant category. The paleoflora is composed mainly of ancient ferns and seed plants, among which, ferns amount to 8 genus 15 species, containing Filicophyta and Sphenophyta; seed plants add up to 15 genus 29 species, contain Ginkgophyta, Cycadophyta and Coniferophyta. Plant fossil assemblage of Emuerhe Group bears the following characteristics： （1）Coniopteris has high diversity and abundance~ （2） the classic Coniopteris burejensis and Eboracia lobifolia in Middle Jurassic have been found~ （3） the simultaneous abundant appearance of Coniopteris, Cladophlebis, Eboracia is the prime feature of the paleoflora in the area. The above characteristics indicate that the Paleoflora belongs to the late Coniopteris - Phoenicopsis flora in Middle Jurassic. According to the comprehensive analysis on longitudinal distribution and combined features of the paleoflora in Emuerhe Group, the late flora combination Coniopteris- Phoenicopsis can be divided into 3 sub-combinations which are Coniopteris- Nilssonia in Xiufeng Formation, Coniopteris - Czekanowskia in Ershierzhan Formation and Coniopteris burejensis - Cladophlebis cf. asiatica in Mohe Formation- Kaikukang Formation. The study on paleoflora in Emuerhe Group not merely enriches the biostratigraphic data in the study area and identifies the geological age of Emuerhe Group which belongs to the Middle Jurassic, but more importantly solves the current basic geological problem of exploration of gas hydrate.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2015年第3期299-309,共11页
Earth Science Frontiers
基金
国家重大专项"东北冻土区天然气水合物资源勘查"(GZHL20120304)
