摘要
为了加强含油气盆地的古环境和古气候研究,寻找古环境研究的多种途径,探索用孢粉信息函数半定量恢复古环境和古气候。孢粉是气候变化敏感的信息载体,气候适宜,孢粉信息函数值越高,而且在沉积过程中,从岸边到湖盆中心,随着水体加深,孢粉信息函数值逐渐降低。利用孢粉信息函数的这种变化规律,按<2.0、2.0—2.1、>2.1三个参数值,将辽河断陷西部凹陷沙河街组一段沉积时期的湖盆划分为半深湖、浅湖和滨浅湖环境。并依据沙河街组孢粉信息函数值从沙四段到沙一段呈现低(1.97)—高(2.12)—低(1.88)—高(2.28)的韵律性变化,判断古气候呈干热—潮湿—干热—潮湿的旋回性演变。西部凹陷沙河街组孢粉信息函数的变化规律与古气候演变有很好的响应,同时与盆地不同发育阶段的古地貌、古环境密切相关。因此,孢粉信息函数是重建古气候、古环境的有效手段之一,能弥补缺少大化石给含油气盆地沉积环境研究带来的不足。
In order to strengthen the research of the palaeoenvironment and palaeoclimate in petroliferous basin, to search for a new method for palaeoenvironmental research, this study is to reconstruct the palaeoenvironment and palaeoclimate using spore pollen information function. Spore-pollen is a sensitive information carrier of climate change. Suitable climate will result in a higher value of spore-pollen information function. And in the process of the deposition from the shore to the center of the basin, with the deepening of water, spore-pollen information function gradually decreased. Based on the spore-pollen information function, 〈2.0,2.0 2.1 or 2〉2.1, the lake in the sedimentary period of the Shahejie Formation is divided into semi deep, shallow or shore shallow water lake environments in the western Depression,Liaohe Fault Basin. The rhythm change of spore-pollen information function values from the Member 4 to Member 1 of the Shahejie Formation shows low （1.97）-- high （2.12） --low （1.88）--high （2.28）, implies a cycle of the palaeoclimate evolution was hot and dry wet--hot and dry--wet. The result suggests that variation of spore-pollen information function of the Shahejie Formation in the western Depression has a good response to the palaeoclimate evolution, which is closely related with the palaeolandform and palaeoenvironment in different developmental stages of the basin. Therefore, the spore-pollen information function is one of the effective means to reconstruct the palaeoclimate and palaeoenvironment.
出处
《微体古生物学报》
CSCD
北大核心
2015年第3期285-291,共7页
Acta Micropalaeontologica Sinica
基金
国家科技重大专项"大型油气田与煤层气开发"子课题"渤海湾盆地北部油气富集规律与增储领域研究"(2011ZX05006-005)资助成果
关键词
孢粉信息函数
古环境
古气候
沙河街组
西部凹陷
辽河断陷
spore-pollen information function, palaeoenvironment, palaeoclimate, Shahejie Formation, western Depression, Liaohe Fault Basin, NE China
