摘要
对末次冰消期以来东海内陆架沉积物磁化率的影响因素及其蕴含的古环境信息进行了探讨。对位于浙闽沿岸泥质沉积中心附近的EC2005孔沉积物磁化率、岩性、粒度、常量元素、矿物以及AMS14C测年数据进行了综合分析,得出以下主要结论：EC2005孔沉积物磁化率的变化受多种因素的制约,不同层位的主要控制因素不同,60.20~28.06 m层主要受岩性控制,28.06~8.40 m层主要受早期成岩还原作用的影响,8.40 m以上层位可能主要受人类活动的影响;岩心底部60.20~41.00 m层磁化率的逐渐降低对应气候暖湿化、湖泊逐渐扩张的过程,这与以往磁化率高值对应于暖湿气候条件的观点不符,说明由于研究区不同,其蕴含的信息也会有所不同;对不同研究区磁化率作为气候代用指标进行应用时要慎重,应该对其指示意义进行深入探讨。
The paleoenvironmental significance of magnetic susceptibility（MS） and its influencing factors in the sediments on the inner shelf of the East China Sea have been discussed since the last deglaciation.On the basis of analysis on the MS,lithology,grain-size,major elements,minerals and AMS14C dating of Core EC2005 which is located in the mud depocenter near the Zhejiang—Fujian coast,main conclusions are summarized as follows.The variations of the MS are affected by many factors and the main influencing factors at different layers change significantly.The MS in core depth 60.20～28.06 m is controlled primarily by lithology,the variations in core depth 28.06～8.40 m are due to the impact of early diagenetic effects on magnetic minerals,and the MS above 8.40 m is likely to be affected by human activities.The decrease of the MS at the bottom of 60.20～41.00 m corresponds to the climate warming and wetting trend,lake expansion that occurred during this period.This view is inconsistent with the previous studies that the high MS value corresponds to the warm and humid climate conditions.It is indicated climatic significance differs in different study areas.Therefore,caution must be exercised when the MS is adopted as climate proxies.Its significance should be discussed in detail.
出处
《海洋学报》
CAS
CSCD
北大核心
2011年第1期91-97,共7页
基金
山东省自然科学基金(ZR2010DL009)
中央高校基本科研业务费专项资金(10CX04004A)
中国科学院海洋研究所海洋地质与环境重点实验室开放基金(MGE2010KG02)
国家自然科学基金(40776030)
中国石油大学博士基金项目(Y0901036)
关键词
东海内陆架
末次冰消期
磁化率
沉积环境
成岩作用
inner shelf of the East China Sea
last deglaciation
magnetic susceptibility
sedimentary environment
diagenesis
