新疆乌伦古湖冰滑痕特征及其形成机理

发布时间：2018-05-12 23:02

本文选题：冰滑痕 + 冰成沉积构造　；参考：《地质论评》2017年01期

【摘要】：新疆乌伦古湖滨湖地区发育一种特殊的冰滑痕。冰滑痕长度可达数十米,宽度可达1~5 m。冰滑痕的形态类似于推土机推过的痕迹,其基本形态由头部、侧翼和滑动面三部分构成。头部发育丘形沙堆,侧翼发育线状沙脊,滑动面总体平整,局部发育冰融沙锥、冰融水滴坑、工具痕、冰融痕、次级滑痕等伴生沉积构造。冰滑痕是湖冰破碎后向岸漂移并在岸上滑移形成的。冰滑痕的形态和规模受湖面风力、湖冰的厚度、湖冰的动能、冰块的大小、冰块底部的光滑程度、湖岸的地形和坡度、湖滩沉积物的粒度和成分构成等多种因素的综合影响。冰滑痕的形成经历了:①湖冰破裂阶段;②浮冰向浅水区运动开始接触湖底阶段;③水下冰滑痕形成阶段;④陆上冰滑痕形成阶段;⑤冰融阶段等5个阶段。冰滑痕主要出现在乌伦古湖的水下滨湖带、冰坝堆积带、湖冰活动带和湖冰影响带等四个微相带。冰滑痕形成后接受湖泊波浪和陆地风的改造并逐渐被埋藏保存到地层记录中。乌伦古湖的冰滑痕是在特殊的气候背景和天气条件下形成的,因而既具有重要的古气候指示意义,又具有重要的古湖泊沉积环境指示意义。
[Abstract]:A special kind of ice slip is developed in the lakeside lake area of Wulungu, Xinjiang. Ice slip marks can reach tens of meters in length and a width of 1 ~ 5 m. The shape of the ice slide is similar to that of the bulldozer, and its basic form is composed of three parts: head, flank and sliding surface. The dune sand pile is developed on the head and the linear sand ridge is developed on the flank, and the sliding surface is generally flat, and the ice and sand thawing cone, the ice water drop pit, the tool mark, the ice melt mark, the secondary slip mark and other associated sedimentary structures are developed locally. The ice slip marks are formed when the lake ice drifts towards the shore after the ice is broken and slips on the shore. The shape and scale of the ice slip are affected by the wind force, the thickness of the ice, the kinetic energy of the ice, the size of the ice, the smoothness of the bottom of the ice, the topography and slope of the lake bank, the granularity and composition of the sediment. The formation of ice slip marks has gone through five stages, I. e., the stage of ice rupture in lake 1 and the movement from floating ice to shallow water. The movement of ice to shallow water begins to contact the bottom of the lake. The stage of formation of underwater ice slide marks is the stage of formation of ice slide marks on land and the stage of ice melting. The ice slip marks mainly appear in the four microfacies zones of the Wulungu Lake, such as the underwater littoral zone, the ice dam accumulation zone, the lake ice active zone and the lake ice influence zone. After the ice slip was formed, it was transformed by lake waves and land winds and gradually buried in stratigraphic records. The glacial slip marks of Ulungu Lake are formed under special climatic background and weather conditions, so they are of important paleoclimate indication significance as well as important paleolake sedimentary environment indicator significance.
【作者单位】：长江大学地球科学学院;中国石油天然气集团公司新疆油田分公司;中国石油天然气集团公司咨询中心;
【基金】：国家自然科学基金资助项目(编号:41172106、41302096)的成果~~
【分类号】：P512.2

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