中文摘要：

南极半岛是对全球变暖最敏感的区域之一,研究其全新世以来的气候变化有助于我们理解南大洋高纬地区的气候变化规律。通过中国第28次南极科学考察在南极半岛Bransfield海峡采集的D1-7岩心样品火山灰丰度统计、粗颗粒组分、粒度组分、硅藻海冰种等研究,重建了该岩心5.83ka以来的古海洋与古气候变化。该岩心可识别出13个火山灰层,其主要来源于Deception岛,并与附近的火山灰记录有很好的对应关系。该区域粗颗粒组分和粒度组分指示了9次IRD事件（IRD 1—9,年龄分别为0.84、0.97、1.18、1.89、2.05、2.25、2.45、4.46和5.09ka）,在晚全新世,尤其是2.5ka以来,频繁出现的IRD事件响应于ENSO活动的强弱,ENSO活动显著增强时,向南极半岛输送的水汽增多,进而使得南极半岛冰川不稳定性增加,融化速度加快,冰川的排泄增加。晚全新世3.5ka以来,硅藻海冰种含量显著增多,指示海冰扩张;同时,分选级粉砂平均粒径的减小指示底流的减弱,反映了晚全新世以来南极半岛区域气候变冷,西风带北移。

英文摘要：

The Antarctic Peninsula is one of the most sensitive areas to recent global warming.The Holocene climatic variation in this area is a key to the understanding of the mechanism of climate changes in the high latitude Southern Ocean.In this study,multiple proxies,such as tephra concentration,content of coarse fractions,grain size,sea ice related diatoms,have been studied for the core D1-7collected at the Bransfield Strait,Antarctic Peninsula region,during the 28 th Chinese National Antarctic Expedition,aiming to learn more about Holocene climatic variation in the Antarctic Peninsula region since the 6ka.Thirteen tephra-bearing layers are identified,which can be regionally correlated and were possibly coming from the Deception Island.Nine Ice Rafted Debris events（IRD 1—9：0.84、0.97、1.18、1.89、2.05、2.25、2.45、4.46 and 5.09ka）were identified.Frequent IRD events during the late Holocene,especially since2.5ka,are tele-connected to the enhanced ENSO variability during this interval,which brings more moisture to the Antarctic Peninsula region and causes the instability of ice shelf.Since 3.5ka,the increase in the sea ice species of diatom along with the decrease of mean grain size of sortable silt suggested the expansion of sea ice and the weakening of bottom current.These data further suggest the late Holocene cooling of the study area,incorporated with northward shift of the Westerly.