新疆罗布泊第四纪盐湖上升卤水流体及其成钾意义

Ascending Brine Fluids in Quaternary Salty Lake of Lop Nur in Xinjiang and Their Significance in Potash Formation

野外调查发现 ,新疆罗布泊罗北凹地等干盐湖地表分布有众多的流体上升或上涌通道 ,其形状特征呈“垂直的孔洞”、“泥火山口”、“枣状小坑”及“粘附沙丘”等。研究认为 ,地下卤水流体过去和现在正是通过这些通道上升 ,至地表排泄或进入盐湖水体及沉积物中 ;这些地下流体主要源于深部地层水和大气循环水等 ;上升流体补给罗布泊的罗北凹地等次级盐湖 ,为钾盐成矿提供重要的物质基础 ,并导致钙芒硝的大量沉积 ,促进了盐类沉积物的成岩过程。同时 。

The Lop Nur salty lake is located in eastern Tarim basin of Xinjiang. At the end of the last century, a large_size brine potash deposit was found in Luobei depression, a sub_basin of the Lop Nur Lake. Lately, it has been discovered that lots of fluid ascending conduits exist in Luobei depression and other sites. These conduits look like such bodies as vertical holes, mud craters, Chinese date_like small pits and sand_attached dunes. The authors hold that the underground brine fluids ascend just through these conduits, discharge at the surface and/or enter lake water or sediments of the Lop Nur Lake. These fluids might originate from deep oilfield water or strata water and atmospheric cycling water. They enter the sub_basins such as the Luobei depression and supply them with a great deal of potassium for the formation of the brine potash deposits. In addition, the addition of these fluids into the lake results in the deposition of enormous amounts of glauberite and stimulates the diagenetic changes of saline minerals_hosted sediments. Moreover, solid potash deposits have been formed at the surface of some sites of Lop Nur.