通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而...通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而下划分的5个声学地层单元与钻孔岩芯划分的5个沉积地层单元具有较好的对应关系。8.2 ka BP左右,全新世海侵使得海水进入深沪湾海域,海平面低于现今海平面10~12 m,气候凉爽;7 ka BP左右海水到达现今海平面位置,并于6 ka BP左右到达最高,约比现今海平面高2~3 m,气候温暖湿润,这一时期,近岸大量裸子植物被海水淹没并被沉积物快速掩埋;5 850~5 642 a BP研究区温度降低,该降温活动持续到2 ka BP左右,气候凉爽干燥;2 ka BP以来温度逐渐上升,600 a BP左右有一个相对冷期,之后温度又逐渐上升至现今水平。展开更多
末次盛冰期(LGM)是距今最近的全球冰量鼎盛时期。这一时期全球显著变冷,气候状态与现代差异巨大,因此成为古气候研究中的热点时期。中国南方地处亚热带气候区,对气候变化响应敏感,有学者已对LGM期间该地区的气候特征进行了初步研究,但...末次盛冰期(LGM)是距今最近的全球冰量鼎盛时期。这一时期全球显著变冷,气候状态与现代差异巨大,因此成为古气候研究中的热点时期。中国南方地处亚热带气候区,对气候变化响应敏感,有学者已对LGM期间该地区的气候特征进行了初步研究,但南方地区内部气候特征的差异仍未得到充分认识。为此文章梳理了LGM时期中国南方不同区域的地质记录,总结了这一时期南方地区气候环境的基本特征,并对其所呈现的区域性差异进行分析。研究表明LGM期间中国南方不同区域的地质载体对气候变化的响应存在两种模式,一种是以冷干的气候特征为主,集中在东南沿海与西南地区;另一种则呈现为寒冷湿润的气候模式,主要集中于长江中下游地区。进一步分析认为北半球夏季太阳辐射减弱和大陆冰盖扩张可能是南方地区冷干气候模式的主要驱动因素,而长江中下游一带的冷湿模式可能与ENSO活动增强和夏季风减弱导致的梅雨量增加有关。上述研究为深入探讨LGM时期中国南方气候特征提供了理论基础,也为预测未来气候变化提供了宝贵的参考。The Last Glacial Maximum (LGM), with striking global cooling and remarkable differences in climate conditions compared to modern times, was the most recent peak in global ice volume, making it one of the hot topics in paleoclimate research. Southern China is located in the subtropical climate zone and is sensitive to the response to climate change. Scholars have conducted preliminary studies on the climate characteristics in the region during the LGM period, but the differences in the climatic characteristics in the southern region are still not fully recognized. Therefore, this paper collected the geological records of different regions in southern China during the LGM period, summarized the basic characteristics of the climatic environment in the southern region, and analyzed the regional differences it presents. The results show that there were two climatic response patterns of geological carriers in different regions of southern China during the LGM period, one of which was dominated by cold-dry climatic characteristics, concentrated in the southeast coastal and southwest regions, while the other was characterized by cold-wet climate, mainly distributed in the middle and lower reaches of the Yangtze River (MLRYR). Further analysis suggested that the weakening summer insolation in the Northern Hemisphere and the expansion of continental ice sheets may be the main driving factors for the cold-dry climate pattern in southern China, while the cold-wet climate in the MLRYR may be related to the increased Meiyu precipitation caused by the enhancement of ENSO activity and the weakening of summer monsoon. The above research provided a theoretical basis for further exploring the climate characteristics of southern China during the LGM period, and provided valuable references for predicting future climate change.展开更多
文摘通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而下划分的5个声学地层单元与钻孔岩芯划分的5个沉积地层单元具有较好的对应关系。8.2 ka BP左右,全新世海侵使得海水进入深沪湾海域,海平面低于现今海平面10~12 m,气候凉爽;7 ka BP左右海水到达现今海平面位置,并于6 ka BP左右到达最高,约比现今海平面高2~3 m,气候温暖湿润,这一时期,近岸大量裸子植物被海水淹没并被沉积物快速掩埋;5 850~5 642 a BP研究区温度降低,该降温活动持续到2 ka BP左右,气候凉爽干燥;2 ka BP以来温度逐渐上升,600 a BP左右有一个相对冷期,之后温度又逐渐上升至现今水平。
文摘末次盛冰期(LGM)是距今最近的全球冰量鼎盛时期。这一时期全球显著变冷,气候状态与现代差异巨大,因此成为古气候研究中的热点时期。中国南方地处亚热带气候区,对气候变化响应敏感,有学者已对LGM期间该地区的气候特征进行了初步研究,但南方地区内部气候特征的差异仍未得到充分认识。为此文章梳理了LGM时期中国南方不同区域的地质记录,总结了这一时期南方地区气候环境的基本特征,并对其所呈现的区域性差异进行分析。研究表明LGM期间中国南方不同区域的地质载体对气候变化的响应存在两种模式,一种是以冷干的气候特征为主,集中在东南沿海与西南地区;另一种则呈现为寒冷湿润的气候模式,主要集中于长江中下游地区。进一步分析认为北半球夏季太阳辐射减弱和大陆冰盖扩张可能是南方地区冷干气候模式的主要驱动因素,而长江中下游一带的冷湿模式可能与ENSO活动增强和夏季风减弱导致的梅雨量增加有关。上述研究为深入探讨LGM时期中国南方气候特征提供了理论基础,也为预测未来气候变化提供了宝贵的参考。The Last Glacial Maximum (LGM), with striking global cooling and remarkable differences in climate conditions compared to modern times, was the most recent peak in global ice volume, making it one of the hot topics in paleoclimate research. Southern China is located in the subtropical climate zone and is sensitive to the response to climate change. Scholars have conducted preliminary studies on the climate characteristics in the region during the LGM period, but the differences in the climatic characteristics in the southern region are still not fully recognized. Therefore, this paper collected the geological records of different regions in southern China during the LGM period, summarized the basic characteristics of the climatic environment in the southern region, and analyzed the regional differences it presents. The results show that there were two climatic response patterns of geological carriers in different regions of southern China during the LGM period, one of which was dominated by cold-dry climatic characteristics, concentrated in the southeast coastal and southwest regions, while the other was characterized by cold-wet climate, mainly distributed in the middle and lower reaches of the Yangtze River (MLRYR). Further analysis suggested that the weakening summer insolation in the Northern Hemisphere and the expansion of continental ice sheets may be the main driving factors for the cold-dry climate pattern in southern China, while the cold-wet climate in the MLRYR may be related to the increased Meiyu precipitation caused by the enhancement of ENSO activity and the weakening of summer monsoon. The above research provided a theoretical basis for further exploring the climate characteristics of southern China during the LGM period, and provided valuable references for predicting future climate change.
