摘要
碳氧同位素可以作为古环境和古气候变化的替代指标,反演古湖泊沉积环境和气候的变化特征。对青藏高原东缘松潘县红土乡中新世马拉墩组湖相碳酸盐岩样品进行了系统的采样和碳氧同位素分析,分析青藏高原东缘松潘地区古湖泊沉积环境和古气候变化,并与青藏高原北部可可西里盆地中新世五道梁群进行对比。对比分析表明,中新世青藏高原东缘和北部气候存在明显差异。青藏高原东缘松潘县红土乡马拉墩组沉积于湿热气候背景下的开放型淡水湖泊环境,碳酸盐岩碳同位素组分主要受湖泊初级生产力影响,在沉积期间,初级生产力有3次快速变化的过程。而青藏高原北部五道梁群沉积于干冷气候背景下的封闭性咸水湖泊环境。
As indicators of palaeoclimatic and palaeo-environmental change, both carbon and oxygen isotopes can be used to finish an inversion of variation in palaeo-lacustrine setting and climate. Many samples are obtained from lacustrine carbonate rock of Miocene Maladun Formation, Hongtu village, Songpan county in eastern Tibetan Plateau. And their carbon and oxygen isotopes are analyzed. Furthermore, the variation in both palao-lacustrine setting and climate is identified for the study area. And this variation is compared to that of the Miocene Wudaoliang Group, Hoh Xil Basin in northern plateau. Results show that there is an obvious climatic difference between eastern and northern plateau. Maladun Formation is deposited at an open freshwater lacustrine setting under humid climate; and for carbonate rock, the component of carbon isotope is affected by lacustrine primary production. During a depositional stage, the production experienced fast change for three times. However, the Wudaoliang Group is deposited at a closed saline laustrine setting under dry and cold climate.
出处
《天然气技术与经济》
2015年第2期17-20,23,共5页
Natural Gas Technology and Economy
基金
国家自然科学重点基金项目(编号:41230313)
关键词
青藏高原
中新世
碳氧同位素
古气候
古环境
Tibetan Plateau,Miocene,carbon and oxygen isotopes,palaeoclimate,palaeo-environment
