Multi-proxy evidence for paleoclimate evolution performed on a paleolake sediment core in the East Asian Monsoon Region
Multi-proxy evidence for paleoclimate evolution performed on a paleolake sediment core in the East Asian Monsoon Region
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DOI：
10.1007/s12665-019-8107-5
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发表时间：
2019-01
影响因子：
2.8
通讯作者：
Longjuan Cheng;W. Ye
中科院分区：
文献类型：
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作者：
Longjuan Cheng;W. Ye
利用粒度、总有机碳（TOC）、有机碳同位素（δ 13 Corg）、C/N比值、孢粉、碳酸盐及其碳氧同位素（δ 18 Ocarb和δ 13 Ccarb）等分析手段，对杭嘉湖平原11.4- 5.0calkaBP的古湖泊沉积序列进行了研究。采用冗余分析（RDA）、排序和相关分析（CA）等方法，定量分析地球化学指标对生物指标（花粉）的影响，更科学、准确地解释各指标的环境意义，为古气候重建提供更可靠的指示。AMS 14 C年龄模型的重建结果表明，早-中全新世的气候演化至少经历了4个阶段：（1）早全新世（11.4- 8.7calkaBP）的逐渐暖湿期; (2)中期持续冷干期（8.7- 8.0calkaBP），降水和气温下降。(3)8.0- 6.6calkaBP是气候变化序列中最湿润、最温暖的阶段，降水和温度显著增加，与全新世气候适宜期相一致。(4)全新世中期（6.6-5.0 cal ka BP）为冷干期，特别值得一提的是发现了大量的Oryzapollens，表明稻作农业发展。特别是这一地区的良渚文化就出现在这个时期。
A sediment succession from a paleolake in the Hangjiahu Plain, Southeast China, covering the period 11.4–5.0 cal ka BP was studied using grain size, total organic carbon (TOC), organic carbon isotope (δ13Corg),C/Nratio, pollen, carbonate and its carbon and oxygen isotopes (δ18Ocarband δ13Ccarb) analysis to reconstruct climate changes. The methods of redundancy analysis (RDA) ordination and correlation analysis (CA) were employed to quantify the influence of geochemical indexes on the biological index (the pollen) and to explain the environmental significance of each proxy more scientifically and accurately, so as to provide more reliable indication for the reconstruction of the paleoclimate. The reconstruction, supported by the AMS14C age modelling, indicates climatic evolution during the Early–Middle Holocene period, at least, experienced four stages: (1) a period of gradual warm and humid during the early Holocene (11.4–8.7 cal ka BP). (2) A middle continuous cold–dry stage (8.7–8.0 cal ka BP), precipitation and temperature declined revealed by the proxies. (3) 8.0–6.6 cal ka BP, which was the wettest and warmest stages in the climate change sequence, precipitation, and temperature increased markedly, and this stage was consistent with the Holocene Climate Optimum. (4) A cold–dry period during the middle Holocene (6.6–5.0 cal ka BP), and particularly worth mentioning was that a large number ofOryzapollens were found which indicated the rice-based agriculture developed. In particular, the Liangzhu Culture in this region appeared at this time.