古地理学报2013，Vol.15Issue(4)：551-564,14.DOI:10.7605/gdlxb.2013.04.044
MIS3以来浙江温瑞平原YQ0902孔古环境与古气候变化记录
Records of palaeoenvironment and palaeoclimate changes since the MIS 3 in Borehole YQ0902 at Wenrui Plain, Zhejiang Province
摘要
Abstract
Borehole YQ0902 is located at the Wenrui Plain along the south flank of Oujiang delta in southern Zhejiang Province.Sedimentary facies,grain-size analysis and AMS 14C dating results show that the palaeosol is underlain by the lagoon facies formed during MIS (Marine Isotope Stage) 3.It was therefore indicated that the sea level in the early and middle MIS 3 should reach a point at least 30 m below the present sea-level (not calibrated by tectonic movement and sediment compaction).The pedogenesis of the palaeosol should have taken place in the MIS 2 and its original strata are lagoon deposits at the lower and floodplain deposits at the top.A transgression-regression sequence overlying the palaeosol was formed in the Holocene and it has similar sedimentary facies assemblages with those at the frontal part of the southern flank of Changjiang delta.The initial flooding surface was formed at about 9 cal ka BP in Borehole YQ0902,suggesting that the sea level at the time was approximately 25 m below the present sealevel.In the middle Holocene,the strengthening East Asia Monsoon (EAM) increased sediment input to the study area by the river or through the longshore currents,consequently resulting in high accumulation rate.The sedimentation rate was low in the Mid-Late Holocene (5 ～ 2 cal ka BP) with stable or a little fall in sea level and the weakened EAM.High resolution X-ray fluoroscopy (XRF) core scanning data of relative element ratios were considered as important proxy of palaeoenvironment and palaeoclimate research.For example,C1/Ti and Fe/Ti are good indices of mariness (the degree connected to sea) and EAM strength,respectively.关键词
MIS 3/瓯江三角洲/东亚季风/海平面变化/XRF岩心扫描Key words
MIS 3/Oujiang delta/East Asia Monsoon/sea level change/XRF core scanning分类
天文与地球科学引用本文复制引用
尚帅,范代读,王强,张梦莹..MIS3以来浙江温瑞平原YQ0902孔古环境与古气候变化记录[J].古地理学报,2013,15(4):551-564,14.基金项目
国家自然科学基金项目(编号:41076016,41276045)、中国地质调查局海保工程专项(编号:GZH201100203)和中央高校基本科研业务费专项资金联合资助 （编号:41076016,41276045）
