[目的]探究中晚全新世环境演化与人类活动之间的相互作用.[方法]针对南海北部泥质陆架区B1047和B1104站位沉积物系统开展粒度、主微量元素、稀土元素、黏土矿物及AMS 14 C等测年综合分析,揭示该地区5.2 ka BP以来的陆源碎屑来源以及环...[目的]探究中晚全新世环境演化与人类活动之间的相互作用.[方法]针对南海北部泥质陆架区B1047和B1104站位沉积物系统开展粒度、主微量元素、稀土元素、黏土矿物及AMS 14 C等测年综合分析,揭示该地区5.2 ka BP以来的陆源碎屑来源以及环境对人类活动的响应机制.[结果]物源分析表明,两站位沉积物主要来源于珠江沿岸流和海南岛碎屑物质,还有少量物质来源于琼州海峡.粒度端元模拟识别出3个端元,EM1/EM3比值对应于南海沿岸流体系中冬季风驱动的华南沿岸流的强弱,反映出东亚季风强弱变化;CIA、Rb/Sr以及黏土矿物比值指示化学风化强度变化.结果显示,化学风化指标与黏土矿物比值的变化呈现频繁波动并持续增强的趋势,重金属富集因子在2.2 ka BP以后与化学风化指标同步增强.[结论]结合粒度、黏土矿物分析以及地球化学元素分析表明,琼州海峡东5.2 ka BP以来的环境-人类活动变化大致可分为3个阶段:5.2~4.5 ka BP期间,南海北部的环境演化过程受气候变冷引发的海平面下降控制;4.5~2.2 ka BP期间,化学风化指标的增强与人类活动的初始增强阶段有关,是人类活动成为主导地质活动开始的时间;2.2 ka BP以来,重金属元素排放强度与化学风化指标呈同步升高特征,人类活动的增强逐渐超过了自然气候对华南大陆的控制,而人类活动反过来又受到东亚季风变化的影响.这些研究结果印证了人类文明发展与自然环境变化相互制约与依存的人地关系,为理解华南地区史前人地关系的演变提供了新的证据.展开更多
本文基于固城湖湖相沉积物中的元素地球化学、磁化率和粒度指标,高分辨率重建苏皖沿江平原全新世以来的水文气候变化;进而结合先秦时期考古遗址的时空分布特征,探讨研究区人地关系的演变历程。结果表明,11.5—7.0 cal ka BP期间,经历新...本文基于固城湖湖相沉积物中的元素地球化学、磁化率和粒度指标,高分辨率重建苏皖沿江平原全新世以来的水文气候变化;进而结合先秦时期考古遗址的时空分布特征,探讨研究区人地关系的演变历程。结果表明,11.5—7.0 cal ka BP期间,经历新仙女木(YD)冷干事件后,气候迅速转为最温暖湿润期,但波动频繁;7.0—5.0 cal ka BP前期气候有向冷干转变的趋势,后期气候暖湿,湖泊水位稳定;5.0—4.0 cal ka BP气候逐渐变干;4.0—1.5 cal ka BP气候波动频繁,经历“湿润—干旱—湿润”的转变过程。1.5 cal ka BP以来人类对环境的影响显著加强。上述水文气候演变过程影响了遗址的空间分布、农业发展和文化兴衰。新石器早期气候波动频繁,人类过于依赖环境,文明发展缓慢;新石器中晚期稳定的水文气候条件为农业发展奠定了生境基础,促进人口扩张;夏时期气候急剧恶化失衡,遗址数量骤减、文化衰退;商周时期水文气候恶劣,人类通过改变生产战略和技术革新以谋求自身生存和发展。随着生产力水平的提高,人地关系演变的主导因子由自然因素逐渐向人为因素倾斜,在一定限度内冷干或暖湿的气候都能推动人类文明的发展。人类从被动顺应到主动适应自然环境,体现了人类与自然环境之间的博弈过程。展开更多
Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(AC...Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(ACA)region.However,debate persists regarding whether dryland lakes in this region exhibited aridification or humidification during the Holocene.Lopnur serves as the terminal lake of Tarim rivers during the Holocene,which offers an ideal natural laboratory to address the questions.In this study,a high-resolution chronological framework was established through precise radiocarbon dating.Multi-proxy analyses,including geochemical composition,grain size distributions,MS,LOI,and C/N ratios were conducted from a lacustrine profile in the core area of“Great ear”in the southern part of Lopnur catchment.These analyses enabled the reconstruction of hydrological dynamics and facilitated the disentanglement of independent signals linked to climate variability,runoff fluctuations,and lake-level changes.The results demonstrate that the MidHolocene(7800–4000 cal yr B.P.)was characterized by cold and humid conditions,resulting in elevated surface runoff and lake level.The Late Holocene(4000–1300 cal yr B.P.)experienced intensified aridification,characterized by reduced runoff and declining lake level.These evidences suggested a climatic regime of a distinctive alternation between“cold-wet”and“warm-dry”climatic regimes during the Mid-to-Late Holocene.Compared with the previous studies from adjacent regions,we speculate that the hydroclimatic evolution of Lopnur catchment possibly influenced by a complex interplay of large spatial scale forcings,including variations in annual insolation,greenhouse gas concentrations,and ice sheets,as well as the localized controls such as topographic features,vegetation cover,and cloud-radiative feedbacks.Our findings enhance the understanding of past climatic complexity and provide valuable insights for future water resource management strategies in drylands.展开更多
淮河是一条对华夏文明具有重大意义的河流。但相较于黄河与长江流域,淮河流域的考古及古环境研究较为滞后。桥头遗址是淮河上游一处以石家河文化为主的重要遗址。本研究通过对桥头遗址区及其临近区域的地层调查和室内样品的测试分析,对...淮河是一条对华夏文明具有重大意义的河流。但相较于黄河与长江流域,淮河流域的考古及古环境研究较为滞后。桥头遗址是淮河上游一处以石家河文化为主的重要遗址。本研究通过对桥头遗址区及其临近区域的地层调查和室内样品的测试分析,对该遗址生成前后的环境变化以及古洪水事件与遗址的存续关系等展开了研究。研究发现:桥头遗址生成前大约在8.1~4.6 ka BP(9.1~5.4 cal.ka BP),遗址所在至少方圆2 km的范围区一直被湖沼所覆盖;4.6 ka BP(5.4 cal.ka BP)以后,温暖湿润的气候、地势较高的湖沼相沉积高地以及紧邻作为遗址水源地的母子河等优越的自然环境,吸引了先民来桥头区域生活;4.0 ka BP的气候异常事件、3.5 ka BP(3.9 cal.ka BP)的气候波动所带来的洪水灾害和3.2 ka BP(3.6 cal.ka BP)的淮河改道等自然环境的频繁变动,使得石家河文化以后的1000年时间内遗址区不适宜人类居住。3 ka BP(3.3 cal.ka BP)之后,桥头遗址所在区域的气温逐渐升高变暖,先人再次在此定居;2.5 ka BP(1.8 cal.ka BP)后,气候的剧烈波动、洪水的频繁泛滥再次威胁到人类在桥头遗址区域生产生活,先人从此地再次迁徙。展开更多
文摘[目的]探究中晚全新世环境演化与人类活动之间的相互作用.[方法]针对南海北部泥质陆架区B1047和B1104站位沉积物系统开展粒度、主微量元素、稀土元素、黏土矿物及AMS 14 C等测年综合分析,揭示该地区5.2 ka BP以来的陆源碎屑来源以及环境对人类活动的响应机制.[结果]物源分析表明,两站位沉积物主要来源于珠江沿岸流和海南岛碎屑物质,还有少量物质来源于琼州海峡.粒度端元模拟识别出3个端元,EM1/EM3比值对应于南海沿岸流体系中冬季风驱动的华南沿岸流的强弱,反映出东亚季风强弱变化;CIA、Rb/Sr以及黏土矿物比值指示化学风化强度变化.结果显示,化学风化指标与黏土矿物比值的变化呈现频繁波动并持续增强的趋势,重金属富集因子在2.2 ka BP以后与化学风化指标同步增强.[结论]结合粒度、黏土矿物分析以及地球化学元素分析表明,琼州海峡东5.2 ka BP以来的环境-人类活动变化大致可分为3个阶段:5.2~4.5 ka BP期间,南海北部的环境演化过程受气候变冷引发的海平面下降控制;4.5~2.2 ka BP期间,化学风化指标的增强与人类活动的初始增强阶段有关,是人类活动成为主导地质活动开始的时间;2.2 ka BP以来,重金属元素排放强度与化学风化指标呈同步升高特征,人类活动的增强逐渐超过了自然气候对华南大陆的控制,而人类活动反过来又受到东亚季风变化的影响.这些研究结果印证了人类文明发展与自然环境变化相互制约与依存的人地关系,为理解华南地区史前人地关系的演变提供了新的证据.
文摘本文基于固城湖湖相沉积物中的元素地球化学、磁化率和粒度指标,高分辨率重建苏皖沿江平原全新世以来的水文气候变化;进而结合先秦时期考古遗址的时空分布特征,探讨研究区人地关系的演变历程。结果表明,11.5—7.0 cal ka BP期间,经历新仙女木(YD)冷干事件后,气候迅速转为最温暖湿润期,但波动频繁;7.0—5.0 cal ka BP前期气候有向冷干转变的趋势,后期气候暖湿,湖泊水位稳定;5.0—4.0 cal ka BP气候逐渐变干;4.0—1.5 cal ka BP气候波动频繁,经历“湿润—干旱—湿润”的转变过程。1.5 cal ka BP以来人类对环境的影响显著加强。上述水文气候演变过程影响了遗址的空间分布、农业发展和文化兴衰。新石器早期气候波动频繁,人类过于依赖环境,文明发展缓慢;新石器中晚期稳定的水文气候条件为农业发展奠定了生境基础,促进人口扩张;夏时期气候急剧恶化失衡,遗址数量骤减、文化衰退;商周时期水文气候恶劣,人类通过改变生产战略和技术革新以谋求自身生存和发展。随着生产力水平的提高,人地关系演变的主导因子由自然因素逐渐向人为因素倾斜,在一定限度内冷干或暖湿的气候都能推动人类文明的发展。人类从被动顺应到主动适应自然环境,体现了人类与自然环境之间的博弈过程。
基金supported by the National Natural Science Foundation of China(No.42001084)the Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(Nos.2022A03009-2,2022A03009)the Third Xinjiang Scientific Expedition Program(No.2022xjkk1303)。
文摘Exploring hydroclimatic variability and its driving mechanisms during the Holocene is essential for comprehending both historical and prospective responses of water resources to climatic shifts in Arid Central Asia(ACA)region.However,debate persists regarding whether dryland lakes in this region exhibited aridification or humidification during the Holocene.Lopnur serves as the terminal lake of Tarim rivers during the Holocene,which offers an ideal natural laboratory to address the questions.In this study,a high-resolution chronological framework was established through precise radiocarbon dating.Multi-proxy analyses,including geochemical composition,grain size distributions,MS,LOI,and C/N ratios were conducted from a lacustrine profile in the core area of“Great ear”in the southern part of Lopnur catchment.These analyses enabled the reconstruction of hydrological dynamics and facilitated the disentanglement of independent signals linked to climate variability,runoff fluctuations,and lake-level changes.The results demonstrate that the MidHolocene(7800–4000 cal yr B.P.)was characterized by cold and humid conditions,resulting in elevated surface runoff and lake level.The Late Holocene(4000–1300 cal yr B.P.)experienced intensified aridification,characterized by reduced runoff and declining lake level.These evidences suggested a climatic regime of a distinctive alternation between“cold-wet”and“warm-dry”climatic regimes during the Mid-to-Late Holocene.Compared with the previous studies from adjacent regions,we speculate that the hydroclimatic evolution of Lopnur catchment possibly influenced by a complex interplay of large spatial scale forcings,including variations in annual insolation,greenhouse gas concentrations,and ice sheets,as well as the localized controls such as topographic features,vegetation cover,and cloud-radiative feedbacks.Our findings enhance the understanding of past climatic complexity and provide valuable insights for future water resource management strategies in drylands.
文摘淮河是一条对华夏文明具有重大意义的河流。但相较于黄河与长江流域,淮河流域的考古及古环境研究较为滞后。桥头遗址是淮河上游一处以石家河文化为主的重要遗址。本研究通过对桥头遗址区及其临近区域的地层调查和室内样品的测试分析,对该遗址生成前后的环境变化以及古洪水事件与遗址的存续关系等展开了研究。研究发现:桥头遗址生成前大约在8.1~4.6 ka BP(9.1~5.4 cal.ka BP),遗址所在至少方圆2 km的范围区一直被湖沼所覆盖;4.6 ka BP(5.4 cal.ka BP)以后,温暖湿润的气候、地势较高的湖沼相沉积高地以及紧邻作为遗址水源地的母子河等优越的自然环境,吸引了先民来桥头区域生活;4.0 ka BP的气候异常事件、3.5 ka BP(3.9 cal.ka BP)的气候波动所带来的洪水灾害和3.2 ka BP(3.6 cal.ka BP)的淮河改道等自然环境的频繁变动,使得石家河文化以后的1000年时间内遗址区不适宜人类居住。3 ka BP(3.3 cal.ka BP)之后,桥头遗址所在区域的气温逐渐升高变暖,先人再次在此定居;2.5 ka BP(1.8 cal.ka BP)后,气候的剧烈波动、洪水的频繁泛滥再次威胁到人类在桥头遗址区域生产生活,先人从此地再次迁徙。
