| 源－汇沉积过程的深时古气候意义 |
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| 引用本文： | 杨江海,马严.源－汇沉积过程的深时古气候意义[J].地球科学,2017,42(11):1910-1921. |
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| 作者姓名： | 杨江海 马严 |
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| 作者单位： | 1.中国地质大学生物地质与环境地质国家重点实验室, 地球科学学院, 湖北武汉 430074 |
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| 基金项目： | 中央高校基本科研业务费专项资金资助项目CUG160604国家自然科学基金项目41572078 |
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| 摘 要： | 源－汇沉积过程的实质是沉积物的产生、搬运和沉积.陆表岩石的风化、侵蚀是沉积物产生的主要过程，受气候和构造因素的联合控制.现代陆表风化层研究揭示，在特定风化机制下（供给限制型化学风化）表层土壤的化学风化强度主要与陆表温度和湿度（降雨量）有关，其关系可通过建立经验气候转换方程来描述.经源－汇过程，这些气候信息可随陆源碎屑沉积物从源到汇传递，并最终可能形成沉积记录而保存于地层序列中.由于源－汇系统的复杂性和自发波动性，气候信息传递受源区侵蚀和沉积路径等的影响和扰动，具有明显的选择性，其时效性与气候变化本身的幅度和频度有关.基于陆源碎屑沉积进行深时古气候研究需要加深对源－汇沉积过程的理解，并考虑沉积系统响应和可能气候变化的时间尺度.
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| 关 键 词： | 源－汇过程 沉积 化学风化 深时古气候 沉积记录 |
| 收稿时间： | 2017-06-06 |
Paleoclimate Perspectives of Source-to-Sink Sedimentary Processes |
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| Abstract: | Source-to-Sink process involves the production, transportation and accumulation of terrigenous clastic sediments. Sediments are produced dominantly by weathering and eroding exposed rocks on continent surfaces, with processes mainly regulated by climate and tectonics. Modern regolith studies document that under specific weathering regime (supply-limited weathering), surface soils can be weathered to certain degrees related to temperature and moisture (precipitation vs. evaporation) and their relationships can be outlined by empirical climate transfer functions. Through Source-to-Sink process, the climate signal can be transmitted, along sediment transport, from the source to the sink and is finally preserved in the sedimentary archives. However, climate signals might be damped or shred by landscape erosion and sediment routing systems due to the complexity and autogenic fluctuations of Source-to-Sink process. The climate signal propagation can be selectively filtered, and its fidelity and efficiency are closely related to the frequency and amplitude of climate changes. Studies of deep-time paleoclimate of terrigenous clastic sequences require a thorough understanding of the Source-to-Sink process and the comparison between timescales of sedimentary system responding and potential climate change. |
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