干旱区生态环境知识资源中心(Arid): 山西左云地区下白垩统左云组沉积相及其古气候意义

Arid

	山西左云地区下白垩统左云组沉积相及其古气候意义
其他题名	Sedimentary Fades of Lower Cretaceous Zuoyun Formation and Paleoclimate of Early Cretaceous
	董黎阳; 伊剑; 刘颖超; 续世朝; 王锁柱; 张财
来源期刊	地质论评
ISSN	0371-5736
出版年	2018
卷号	64 期号:2 页码:392-404
中文摘要	最近,山西左云地区下白垩统左云组中发现了保存完好的剑龙化石,笔者对左云组的沉积相、剑龙的埋藏环境及当时的古气候和进行了分析.系统的沉积学研究表明,左云组为一套典型的洪积扇沉积,是由泥石流和暂时性水流作用交替发育而形成的产物.根据岩性特征和剖面结构,可将左云组划分为扇根、扇中、扇缘及扇间四个亚相,剖面上可进一步识别出泥石流沉积、主槽一河道、漫洪一漫流带、辫流线四个微相.结合孢粉及古生物数据分析,早白垩世晚期,左云地区总体为亚热带沙漠边缘干旱环境,但仍体现出干旱和潮湿的无规律变化,突发的季节性暴雨或特大暴雨(千年一次)的出现,形成特大洪峰,短时间内形成巨厚的洪积扇砾岩一泥岩.剑龙埋藏环境为扇根一扇中部位漫洪一漫流带,是特大洪水期溢出主槽而于山前形成的片汜沉积,剑龙陷于厚层泥质中而被埋藏保存下来.
英文摘要	Objectives: Recently, well-preserved Stegosaur fossils were discovered in the Lower Cretaceous Zuoyun Formation, which is a typical continental deposits, in Zuoyun area, Shanxi Province. Sedimentary facies of the Zuoyun Formation and burial environment of Stegosaur have been analysised based on geological section and sedimentology research. Furthermore, paleoclimate of the Zuoyun stage has been discussed based on aforementioned analysies. Methods: Firstly,we classify the Zuoyun Formation as a set of proluvial fan deposits based on lateral distribution and vertical thickness changes of interbedding of conglomerate and mudstone in the Zuoyun Formation. Furthermore, hydronamic mechanism of proluvial fan has been analysised and subfacies and microfacies have been recognized based on variation of lithofacies,interior fabric,sedimentary structures from the bottom to top. Results: Systematic sedimentology research have disclosed that the Zuoyun Formation belongs to typical proluvial fan deposits,produced by alternative debris flow and temporary stream flow processes. Based on lithologic characteristics and profile section structures,the Zuoyun Formation may be divide into three subfacies,namely the fan top,middle fan and fan margin,further four microfacies can be recognized in the profile,namely debris flow deposits,main ravinechannel,flood zoneflood flow zone,braided stream. Conclusions: Analysis combined with palynological and paleotological data indicates that Zuoyun area was generally dominated during Early Cretaceous by arid environment of subtropical desert periphery,accompanied by irregular alternation of arid and humid,during which catastrophic flood peak formed by monsoonal to millennial sudden rainstorm or extraordinary rainstorm may result in thick proluvial fan conglomeratemudstone deposits.
中文关键词	左云组 ; 剑龙 ; 沉积相 ; 洪积扇 ; 古气候
英文关键词	Zuoyun Formation sedimentary facies proluvial fan paleoclimate
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:6197855
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/237471
作者单位	山西地质博物馆, 太原, 山西 030001, 中国
推荐引用方式 GB/T 7714	董黎阳,伊剑,刘颖超,等. 山西左云地区下白垩统左云组沉积相及其古气候意义[J],2018,64(2):392-404.
APA	董黎阳,伊剑,刘颖超,续世朝,王锁柱,&张财.(2018).山西左云地区下白垩统左云组沉积相及其古气候意义.地质论评,64(2),392-404.
MLA	董黎阳,et al."山西左云地区下白垩统左云组沉积相及其古气候意义".地质论评 64.2(2018):392-404.