四海龙湾沉积物多指标反映人类活动从1850年开始显著增强  

Significant Increase in Human Activities Since 1850 According to Multiple Proxies of Sihailongwan Maar Lake Sediment

作　　者：江鸿 韩永明[1,2,3] 刘卫国 曹蕴宁[1] 胡婧 樊会敏[1] 刘博[1] Hong JIANG;Yongming HAN;Weiguo LIU;Yunning CAO;Jing HU;Huimin FAN;Bo LIU(State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China;School of Human Settlements and Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China;National Observation and Research Station of Regional Ecological Environment Change and Comprehensive Management in the Guanzhong Plain,Xi’an 710061,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,陕西西安710061 [2]西安交通大学人居环境与建筑工程学院,陕西西安710049 [3]陕西关中平原区域生态环境变化与综合治理国家野外科学观测研究站,陕西西安710061 [4]中国科学院大学,北京100049

出　　处：《地球科学进展》2024年第1期82-95,共14页Advances in Earth Science

基　　金：国家自然科学基金重大项目(编号:41991250);国家自然科学基金创新群体项目(编号:42221003);中国科学院先导专项(编号:XDB40000000)资助。

摘　　要：基于全球地质记录的比对,国际人类世工作组建议20世纪中期(约1950年)为人类世的起始时间,四海龙湾沉积物曾被列为“人类世界线层型剖面”的候选地质体之一。但在1950年以前,人类已较深刻地影响了四海龙湾周围地区的环境。通过重建四海龙湾沉积物900年以来的总有机碳、总有机碳和总氮的摩尔比(C/N)、稳定有机碳同位素(δ^(13)C_(org))和Ca/Ti,以及硅酸盐矿物主要元素Si、Al和K含量的历史序列,平均分辨率约为10年,以气候变化为背景,来探究该地区人类活动的历史。发现人类活动从1850年开始显著增强,在此之前的中世纪暖期和小冰期指标变化大体符合自然规律。1850—1950年指标的变化反映出快速增长的人口破坏了植被,导致风化加剧,地表环境的演变脱离了自然轨道,表明人类活动开始成为一种重要的地质营力,但这段时期的变化只是局地信号;1950年后,C/N持续减小及δ^(13)C_(org)持续负移,反映出在新的社会制度和先进生产力的条件下,四海龙湾周围地区的环境状态再次发生改变,这与全球地质环境的加速变化同步,可以支持国际人类世工作组所提出的“20世纪中期是人类世的起始时间”。Based on a global comparison of geological records,the International Anthropocene Working Group(AWG) determined that the onset of the Anthropocene was sometime in the mid-twentieth century (~1950 CE),and the Sihailongwan Maar Lake has been included as one of the candidate sites for the Global boundary Stratotype Section and Point (GSSP) of the Anthropocene.However,humans had a profound impact on the environment of the areas around Sihailongwan Maar Lake even before 1950 CE.Historical sequences of TOC contents,C/N ratios,δ^(13)C_(org) values,Ca/Ti ratios,and concentrations of silicate major elements,such as Si,Al,and K,since 900 CE were reconstructed,with the average resolution being~10 a,to explore the history of human activities in this region under the background of climate change.Human activities have significantly increased since 1850 CE,and changes in the measured proxies during the Medieval Warm Period and Little Ice Age before1850 CE generally follow natural laws.The changes in the measured proxies during 1850-1950 CE indicate a rapid population growth,which damaged vegetation and resulted in intensified weathering and deviation of the surface environment evolution from the natural state.Hence,humans had started to be an important force for the geological environment;nevertheless,the changes during this period resulted in mostly local signals.After 1950 CE,the C/N ratios and δ^(13)C_(org) values decreased continuously,indicating that the environmental status of the area around Sihailongwan Maar Lake changed once again under the new government and advanced productivity.This was in sync with the Great Acceleration of the global geological environment and supports the conclusion of the AWG that the onset of the Anthropocene was sometime in the mid-twentieth century.

关 键 词：人类世 四海龙湾 地表风化 毁林垦荒 东北地区 人口增长 

分 类 号：P534[天文地球—古生物学与地层学]