中更新世以来哈尔滨黄土有机碳同位素组成及其古气候意义  

Organic Carbon Isotope Composition of Harbin Loess since the Mid-Pleistocene and Its Paleoclimatic Significance

作　　者：张月馨 迟云平[1,2] 谢远云[1,2] 康春国[3] 吴鹏 魏振宇 张曼 刘璐 ZHANG Yue-xin;CHI Yun-ping;XIE Yuan-yun;KANG Chun-guo;WU Peng;WEI Zhen-yu;ZHANG Man;LIU Lu(College of Geographic Science,Harbin Normal University,Harbin,Heilongjiang 150025;Heilongjiang Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions,Harbin Normal University,Harbin,Heilongjiang 150025;Department of Geography,Harbin Institute,Harbin,Heilongjiang 150086)

机构地区：[1]哈尔滨师范大学地理科学学院,黑龙江哈尔滨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,黑龙江哈尔滨150025 [3]哈尔滨学院地理系,黑龙江哈尔滨150086

出　　处：《地球学报》2020年第4期525-534,共10页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41601200,41871013);黑龙江省自然科学基金项目(编号:D2017003);哈尔滨师范大学博士科研启动基金项目(编号:XKB201418)联合资助。

摘　　要：研究黄土-古土壤序列有机碳同位素组成与古植被和古气候的关系,对于重建第四纪环境变化过程有重要意义。然而,东北地区黄土有机碳同位素组成的研究尚未展开。本文对哈尔滨荒山岩芯开展了黄土-古土壤序列的有机碳同位素组成和磁化率分析。结果表明,中更新世以来有机碳同位素组成在古土壤层和黄土层的均值分别为–24.8‰和–25.1‰,整体上古土壤层有机碳同位素组成较黄土层偏正,而S0和S2古土壤层相对偏负。利用端元法恢复过去C3/C4植物的相对丰度,揭示出中更新世以来研究区C3植物占绝对优势地位。通过与海面温度和深海氧同位素以及东北地区赤峰黄土的有机碳同位素进行耦合对比,发现荒山岩芯的有机碳同位素组成变化与温度呈正相关,表明温度是植物碳同位素组成变化的主控因素。然而在某些间冰期时期,比如S0、S2层以及S3古土壤层中部,降水可能成为主要因素。上述研究表明东北地区植物生长对气候响应具有复杂性。这些认识对于理解哈尔滨地区C3植物的生长因子具有重要的借鉴意义。The research on the relationship between organic carbon isotope composition of loess-paleosol sequence and paleo-vegetation as well as paleoclimate has great significance for the reconstruction of Quaternary environmental change process. However, the research on the organic carbon isotope composition of Harbin loess in Northeast China has not been carried out. In this paper, the authors analyzed the organic carbon isotope composition and magnetic susceptibility of the loess-paleosol sequence of Harbin Huangshan core. The results show that the average organic carbon isotopic compositions in the paleosol and loess layer since the Middle Pleistocene are –24.8 ‰ and –25.1 ‰, respectively. On the whole, the organic carbon isotope composition of the paleosol layer is more positive than that of the loess layer, while the values of S0 and S2 paleosol layers are relatively negative. The relative abundance of C3/C4 plants in the past was restored by the end element method, which has revealed that C3 plants have been dominant in the study area since the Middle Pleistocene. Through the coupling comparison with sea surface temperature, deep-sea oxygen isotope and organic carbon isotope of Chifeng loess in Northeast China, it is found that the change of organic carbon isotope composition in Huangshan core is positively correlated with temperature, indicating that temperature is the main controlling factor of the change of plant carbon isotope composition. However, during some interglacial periods, such as the S0, S2 paleosol layer and the middle of S3 paleosol layer, precipitation may be a major factor. The above study shows that the response of plant growth to climate in Northeast China is complex. The understanding obtained by the authors has important reference significance for the growth factors of C3 plants in Harbin.

关 键 词：哈尔滨 有机碳同位素组成 C3植物 温度 降水 

分 类 号：P597.3[天文地球—地球化学] P532[天文地球—地质学]