松嫩平原中更新世以来气候干旱化——来自哈尔滨黄土记录  

Climatic Aridification in Songnen Plain Since the Middle Pleistocene from Harbin Loess Records

作　　者：赵倩 谢远云[1,2] 郝冬梅[1] 迟云平[1,2] 康春国[3] 吴鹏 刘硕[1] ZHAO Qian;XIE YuanYun;HAO DongMei;CHI YunPing;KANG ChunGuo;WU Peng;LIU Shuo(School of Geographical Sciences,Harbin Normal University,Harbin 150025,China;Heilongjiang Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Region,Harbin Normal University,Harbin 150025,China;Department of Geography,Harbin University,Harbin 150086,China)

机构地区：[1]哈尔滨师范大学地理科学学院,哈尔滨150025 [2]哈尔滨师范大学寒区地理环境监测与空间信息服务黑龙江省重点实验室,哈尔滨150025 [3]哈尔滨学院地理系,哈尔滨150086

出　　处：《沉积学报》2022年第6期1702-1717,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41871013);黑龙江省自然科学基金(LH2020D009)。

摘　　要：哈尔滨黄土位于欧亚黄土带最东端,是研究气候干旱化的理想载体,对于重建松嫩平原气候干旱化历史及完善亚洲内陆干旱化东进进程具有重要意义。然而,松嫩平原干旱化的相关研究相当薄弱,黄土与区域构造—气候—水系演化之间的耦合关系尚未明确。对哈尔滨黄土—古土壤序列进行了沉积学特征分析以及粒度、磁化率、总有机碳和Sr-Nd同位素组成测试,结合粒度端元和小波分析,对松嫩平原气候干旱化历史及驱动机制进行研究。结果表明:受高纬度寒冷气候影响,哈尔滨黄土—古土壤序列的沉积特征与其他地区存在显著差异,潜育化的沉积环境是古土壤层磁化率呈现低值的主控因素;哈尔滨黄土堆积的出现指示了松嫩平原干旱化和松嫩沙地的发育始于~460 ka;黄土大于63μm以及EM3端元组分共同指示了380 ka和300 ka两次明显的干旱化加剧和沙地扩张事件;TOC和Sr同位素指标揭示了这种干旱化加剧的现象一直持续到180 ka。此后,松嫩平原的气候逐渐趋于暖湿。研究显示,全球气候变冷(冰量的扩增)—区域构造(松辽分水岭隆起)—水系演化(松辽水系的变迁)共同驱动了松嫩平原气候干旱化。上述认识对松嫩平原的生态与社会经济的可持续发展具有重要意义。The Harbin loess is located in the easternmost part of the Eurasian loess belt.It is an ideal material for re⁃constructing the history of aridification of the Songnen Plain and determining the eastward advance of inland Asia.However,research on aridification of the climate in the Songnen Plain is quite weak.The relationships between aridi⁃fication,tectonism,climate and drainage evolution in the area are currently poorly understood.In this study,these sedimentary characteristics,grain-size,magnetic susceptibility,total organic carbon and Sr-Nd isotopes are present⁃ed,combined with grain size end-member and wavelet analysis,to examine the history and driving mechanism of cli⁃mate aridification in the Songnen Plain.It was found that due to the high-latitude cold climate,deposition of the Har⁃bin loess-paleosol sequence was significantly different from that in other regions.The gleization sedimentary environ⁃ment is the main controlling factor for the low magnetic susceptibility of the paleosol layer;the appearance of the Har⁃bin loess indicates the climate aridification of the Songnen Plain.The Songnen sandy land began to develop at about 460 ka;loess>63μm and the EM3 end member component together clearly indicate the occurrence of two aridifica⁃tion and sandy expansion events at 380 ka and 300 ka.The Sr and Nd isotopes and TOC indicators reveal that the aridification phenomenon continued until 180 ka,after which the climate of the Songnen Plain gradually became warmer and wetter.Global climate cooling(enlargement of ice areas),regional tectonism(uplift of the Songliao wa⁃tershed),and drainage change(altered Songliao water system)were collectively responsible for aridification in the Songnen Plain.This study is of great significance to the sustainable developmentof the ecology and social economy of the Songnen Plain.

关 键 词：哈尔滨黄土 松嫩平原 气候干旱化 粒度 端元分析 小波分析 

分 类 号：P531[天文地球—古生物学与地层学]