Geochemistry of Russian Rivers

9304843埃德蒙德目前在俄罗斯远东的大河中可以不受限制地获取和采样。对上勒拿河的主要支流阿尔丹河(1991年)和科里马河(1992年)进行了两次非常成功的探险。对所有重要支流进行了水化学及其悬浮物和底质的采样。现在可用于Aldan系统的数据清楚地显示了冰缘环境中霜裂对加速风化的影响。太古宙Aldan盾似乎比其热带类似物--奥里诺科河流域的瓜亚纳盾--的耐受性至少快一个数量级。同样，Lena高原台地碳酸盐的风化速率也不受低温的抑制。夏季径流期间的浓度水平与长江相当，后者排水的地形相似。这些比较揭示了气候恶化对地球化学循环的影响，这是目前普遍感兴趣的一个话题。计划将这项工作扩大到上勒拿河的主干流和该地区的其他大型河流，如印迪克里卡河、亚纳河、阿纳德尔河和阿穆尔河。***

9304843 Edmond Unrestricted access and sampling is currently possible in the great rivers of the Russian Far East. Two very successful expeditions have taken place to the Aldan, the major tributary of the Upper Lena (1991), and to the Kolyma (1992). All significant tributaries were sampled for water chemistry and for their suspended and bed material. The data now available for the Aldan system clearly show the effects of frost cracking in accelerating weathering in this periglacial environment. The Archean Aldan Shield appears to weather at rates at least an order of magnitude faster than its Tropical analogue, The Guayana Shield in the Orinoco drainage. Similarily the rates of weathering of the platform carbonates of the Lena Plateau are not inhibited by the low temperatures. Concentration levels during the period of summer flow are comparable to those of the Yangtze, which drains geologically similar terrain. These comparison give insight on the effects of climatic deterioration on the geochemical cycle, a topic of much general interest at the present time. It is planned to extend this work to the main stem of the Upper Lena and to the other large rivers of the region, the Indigrika, Yana, Anadyr and Amur. ***