干旱区生态环境知识资源中心(Arid): 西藏札达盆地晚上新世一早更新世孢粉组合及其地质意义

Arid

	西藏札达盆地晚上新世一早更新世孢粉组合及其地质意义
其他题名	Geological Significances of Late Pliocene-Early Pleistocene Palynological Assemblage in Zanda Basin, Tibet
	江尚松 1; 向树元 2; 徐亚东 1
来源期刊	地质科技情报
ISSN	1000-7849
出版年	2010
卷号	29 期号:4 页码:21-31
中文摘要	札达盆地位于青藏高原西南隅的阿里地区,是在中新世晚期约9.6 Ma B.P.形成的一个NW-SE向断陷盆地.该盆地在上新世一早更新世发育一套完整的河湖一冲积扇相地层.在札达县香孜乡西北约1 km处精细实测了上上新统一下更新统香孜剖面.根据前人的古地磁及ESR年龄数据确定下更新统香孜组年龄为2.60~1. 67 Ma B.P..根据孢粉学研究把香孜剖面自下而上划分为3个孢粉组合带(8个孢粉组合),并据此将札达盆地2. 75 Ma B.P.以来的气候变化划分为3个阶段:(1)孢粉组合带I(孢粉组合1 ~2),植被为温暖偏湿的常绿与落叶针阔叶混交林,2. 67 Ma以后气候逐渐向干旱转变,地层对比时代为晚上新世(2. 75~2. 60 Ma); (2)孢粉组合带II(孢粉组合3--5),发育温凉偏湿的亚高山落叶针阔叶混交林,并在约2.38 Ma逐渐变为针叶林,气候趋向变冷,地层对比时代为早更新世(2.54~2.16 Ma);(3)孢粉组合带Ⅲ(孢粉组合6~8),发育寒冷干旱的高山针叶林,并存在高寒灌丛草甸草原,低海拔处零星分布落叶针阔叶混交林,指示较强的地势差异,地层对比时代为早更新世(2.13~1. 86Ma).
英文摘要	The Zanda Basin is a northwest-southeast extensional basin distributed in Nagri area, southwest of Tibet, formed in Late Miocene, about 9. 6 Ma. It contains a well preserved series of lacustrine, fluvial and alluvial sediments. A study is made of one section in the basin located l km northwest of Xiangzi Village, Zanda County. Based on the previous ESR and paleomagnetostratigraphic research, the age interval of the Xiangzi Formation is dated most reasonably between 2.6 Ma B. P. and l.67 Ma B.P.. Through abundant palynological analyses, 3 palynological zones and 8 palynological assemblages and vegetable types are recognized, and 3 phases of paleoclimatic changes are revealed: (1) 2.75-2.60 Ma, correlated with palynological zone I and assemblage l-2, when it was warm and damp-humid with coniferous-leaved and broad-leaved mixed forests, but the climate changed to dump-dry after 2. 67 Ma.(2) 2.54-2.16 Ma, correlated with palynological zoneu and assemblage 3-5, when it turned to cool and humid deciduous coniferous-leaved and broad-leaved mixed forests, and gradually changed to cold deciduous coniferous-leaved forests, indicated by the increase in the cold-tolerant tree taxa. (3) 2. 13-1. 86 Ma, correlated with palynological zone III and assemblage 6-8, the increase of cold-tolerant bush taxa and drought-tolerant herb taxa suggested the climate change into cold and arid, while coniferous-leaved and broad-leaved mixed forests survived at the low altitude.
中文关键词	青藏高原 ; 札达盆地 ; 孢粉组合 ; 古气候变化 ; 晚上新世一早更新世
英文关键词	Qinghai-Tibetan Plateau Zanda Basin palynological assemblage palaeoclimatic change Late Pliocene-Pleistocene
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:3919561
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/224855
作者单位	1.中国地质大学(武汉)研究生院, 生物地质与环境地质教育部重点实验室, 武汉, 湖北 430074, 中国; 2.中国地质大学(武汉)地球科学学院, 武汉, 湖北 430074, 中国
推荐引用方式 GB/T 7714	江尚松,向树元,徐亚东. 西藏札达盆地晚上新世一早更新世孢粉组合及其地质意义[J],2010,29(4):21-31.
APA	江尚松,向树元,&徐亚东.(2010).西藏札达盆地晚上新世一早更新世孢粉组合及其地质意义.地质科技情报,29(4),21-31.
MLA	江尚松,et al."西藏札达盆地晚上新世一早更新世孢粉组合及其地质意义".地质科技情报 29.4(2010):21-31.