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| 宇宙成因核素26Al/10Be约束贵州涟江流域沉积物埋藏历史 |
| In-Situ Cosmogenic Nuclide 26Al/10Be Constraints the Burial History of Sediments in Lianjiang Drainage, Guizhou |
| 投稿时间：2021-05-09 修订日期：2021-09-08 |
| DOI：10.14050/j.cnki.1672-9250.2022.50.012 |
| 中文关键词: 26Al/10Be 河流沉积物 埋藏历史 剥蚀速率 涟江流域 贵州 |
| 英文关键词: 26Al/10Be river sediment burial history denudation rate Lianjiang drainage Guizhou |
| 基金项目:《第二次青藏高原综合科学考察》项目（2019QZKK0707）。 |
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| 中文摘要: |
| 贵州喀斯特地区位于青藏高原向丘陵地貌转换过渡带，区内发育多级层状地貌面，是研究区域构造-气候-剥蚀耦合作用的天然实验场。本文测定了贵州省惠水县境内涟江I级阶地沉积物中原位宇宙成因核素10Be和26Al浓度，通过暴露-埋藏模型对沉积物埋藏历史和物源进行研究。与前人研究结果相比，涟江流域单核素剥蚀速率（10Be平均剥蚀速率为10.85±0.97 m/Ma）显著低于贵州高原其他流域。结合双核素暴露-埋藏模型，研究结果表明更新世以来沉积物样品可能经历了复杂暴露-埋藏-再暴露过程，其物源可能是异地埋藏或洞穴堆积等非稳态剥蚀区。宇宙成因核素对26Al-10Be联用能有效判别非稳态剥蚀过程，弥补了单核素不能表征沉积物埋藏历史的不足。 |
| 英文摘要: |
| Located in the transitional zone from Tibet plateau to hilly landform, Guizhou karst area is characterized by multi-layered landform surfaces, and is considered as a natural experimental field for studying the coupling effect of regional tectonics-climate-denudation. In this study, two riverine sediments were collected from Lianjiang catchment and analyzed for the in-situ cosmogenic nuclide 10Be and 26Al concentrations from which the burial history and provenance were studied by the exposure-burial model. Compared with previous studies, the denudation rates (10.85±0.97 m/Ma) of single nuclide (10Be) in the Lianjiang River Drainage are significantly lower than that in other drainages of the Guizhou Plateau. Combined with the dual-nuclide exposure-burial model, the results indicate that the sediment samples may have experienced a complex exposure-burial-re-exposure process since the Pleistocene, and the provenance may be in the non-steady denudation zones, such as heterochthonous burial or speleothem. The combination of cosmogenic nuclides 26Al and 10Be can effectively distinguish the unsteady denudation process, which makes up for the deficiency that single nuclide cannot characterize the complex burial history of sediments. |
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