| 引用本文: | 李小然,于兆杰,李鑫雨,唐小洁,宋泽华,康晓莹,COLIN Christophe,万世明.40 ka以来苏拉威西海沉积粒度记录[J].海洋科学,2025,49(10):26-38. |
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| 40 ka以来苏拉威西海沉积粒度记录 |
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李小然1,2, 于兆杰1,2, 李鑫雨2, 唐小洁3, 宋泽华2, 康晓莹2, COLIN Christophe3, 万世明2
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1.山东科技大学地球科学与工程学院, 山东 青岛 266590;2.中国科学院海洋研究所中国科学院海洋地质与环境重点实验室, 山东 青岛 266071;3.巴黎萨克雷大学地球科学学院, 法国 91405
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| 摘要: |
| 印度洋-太平洋暖池是全球海-气、海-陆相互影响最活跃的区域之一, 是全球重要的物质和能量交换场所。印度尼西亚贯穿流是低纬度地区连接太平洋和印度洋的主要通道, 在全球气候变化中扮演着重要的角色。前人使用海洋自生碳酸盐组分的δ18O、δ13C以及陆源组分的元素比值等指标开展了大量有关印度尼西亚贯穿流强度以及水体物理性质等的重建研究, 取得了丰富的成果。但是, 目前对印度尼西亚贯穿流的认识仍局限于上层海水, 对中深层洋流的了解仍然甚少。本文测试了加里曼丹岛东北部海岸外MD98-2178钻孔的40 ka以来446个沉积物样品的粒度组成, 并利用端元模拟算法进行分析。结果显示, 两端元模型可代表粒度90%的变化; 40 ka以来岩芯细端元EM1和粗端元EM2的比值记录(EM1/EM2)与指示底层洋流流速变化的分选粒度记录表现出一致的变化。进一步将粗端元EM2和分选粒度记录与格陵兰冰芯δ18O、南极Maud冰芯δ18O、当地降水、海平面变化等记录进行对比, 提出研究区粒度端元变化主要受到局部洋流强度变化的影响, 而非物源区降水主导的风化剥蚀过程。 |
| 关键词: 粒度 苏拉威西海 端元模拟 印度尼西亚贯穿流 |
| DOI：10.11759/hykx20240422002 |
| 分类号:P736.21 |
| 基金项目:国家自然科学基金项目(42376055, W2421051); 中国科学院(Ｂ类)战略性先导科技专项项目(XDB42000000); 山东省优秀青年基金项目(ZR2022YQ33) |
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| Record of the grain size of Sulawesi Sea sedimentation since 40 ka |
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LI Xiaoran1,2, YU Zhaojie1,2, LI Xinyu2, TANG Xiaojie3, SONG Zehua2, KANG Xiaoying2, COLIN Christophe3, WAN Shiming2
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1.College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;2.Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;3.Faculty of Earth Sciences, Université Paris-Saclay, Paris 91405, France
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| Abstract: |
| The Indo-Pacific Warm Pool is among the most active regions for ocean-atmosphere and ocean-land interactions globally, serving as a crucial site for global material and energy exchange. The Indonesian throughflow (ITF) serves as the primary low-altitude pathway connecting the Pacific and Indian Oceans, playing a significant role in regulating global climate change. Previous studies have used various proxies, including stable oxygen and carbon isotope ratios (δ18O and δ13C) of marine authigenic carbonates and elemental ratios of terrigenous components, to reconstruct ITF strength and water-mass properties, yielding substantial results. However, the current understanding of the ITF remains largely confined to the upper ocean layer, with limited knowledge of intermediate- and deep-ocean currents. To bridge this gap, this study analyzed the grain size compositions of 446 sediment samples from core MD98-2178, located off the northeastern coast of Borneo, spanning the last 40 ka. End-member (EM) modeling algorithms were applied to the grain size data to decompose the sedimentary components. The results show that a two-EM model accounts for 90% of grain size variability. Over the past 40 ka, the fine EM (EM1) to coarse EM (EM2) ratio (EM1/EM2) has exhibited consistent variation with the sortable silt (SS) record, reflecting fluctuations in deep bottom current velocity. Further comparison of the EM2 and SS grain size records with δ18O data from the Greenland and Antarctic (Maud) ice cores, alongside local precipitation and sea-level changes, suggests that the grain size EM variations in the study area are mainly driven by changes in the local current intensity and not by precipitation-driven weathering and denudation in the source region. |
| Key words: grain size Sulawesi Sea end-member modeling Indonesian throughflow |
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