柴达木盆地盐湖卤水型锂矿源汇过程及流域水文地貌演化与成矿联系

Source-sink Process of Brine-type Lithium Deposits in the Salt Lakes in the Qaidam Basin and Its Spatial Mineralization Association with Hydrogeomorphic Evolution of Nalinggele River

中文关键词:  卤水型锂矿  柴达木盆地  源汇过程  水文地貌约束

英文关键词:Brine-type Li deposits  Qaidam Basin  Source-sink process  Hydrogeomorphic constraints

中文摘要:

      锂是一种重要的能源金属，随着新能源汽车及储能材料的广泛应用，全球锂资源需求量快速增加，预计未来十年内中国锂资源年需求量超过百万吨。锂矿主要分为三种类型，硬岩型、卤水型和沉积型。我国卤水型锂矿集中分布于青藏高原盐湖区，其中柴达木盆地盐湖锂资源最为集中，开发程度最高，是我国重要的盐湖锂资源产业基地。柴达木盆地一里坪、东-西台吉乃尔盐湖和察尔汗盐湖別勒滩区段卤水锂含量最高，是盆地主要的锂矿沉积区，流域锂资源的源-运-汇过程在盐湖卤水锂成矿中最具代表性，物质来源为那陵格勒河上游支流洪水河流域沿昆仑断裂分布的富锂热泉水补给，河水是携锂运移的主要载体，河水中的锂在出山口后历经多级冲积扇发生水岩反应(地表水/地下水转化与黏土矿物吸附/解吸)后到达尾闾盐湖区，最终蒸发浓缩富集成矿。同时，那陵格勒河流域中多级冲积扇的沉积演化制约着河流的摆动及锂的补给，导致尾闾盐湖成盐成矿时代和资源富集特征存在一定的差异，即成盐厚度东西端厚、中间薄，成盐时代西端老、东端新，而资源量东端富、西端少。因此，柴达木盆地中部富锂盐湖卤水矿床源-运-汇过程及那陵格勒河流域水文地貌演化研究是揭示尾闾盐湖成盐成矿及其空间差异联系的重要研究内容。

英文摘要:

      Lithium (Li) is classi?ed as an energy-critical metal. The demand for Li resources in the world is rapidly increasing with the widespread use of new energy vehicles and energy storage materials， and is expected to exceed one million tons in the next decade in China. The main types of Li deposits can be divided into three types， including hard rock， brine and sedimentary types. In China， Li resources are abundant and the reserves of brine-type resource is the largest in the salt lakes on the Qinghai-Tibetan Plateau (QTP). The Qaidam Basin (QB) in the northern QTP has the largest reserves of Li resources and the highest degree of development， and is an important industrial base for Li-salt products in China. The main Li deposits in the QB are Yiliping， East and West Taijnar salt lakes， and Bieletan section in Qarhan Salt Lake， and the studies on source-sink process and enrichment characteristics of Li resources in this basin are the most representative among brine-type mineralization in salt lakes. The provenance of Li in the lithium-rich salt lakes in the central QB is lithium-rich thermal spring water distributed along the Kunlun Fault and then inflowed into the Hongshui River (a tributary of the Nalinggele River). The river water is the main carrier of Li， and the Li is recharged to the terminal salt lakes following through multi-level alluvial fans and experienced water-rock interaction (surface water-groundwater exchange and adsorption/desorption of clay minerals)， and finally enriched by evaporation and concentration in the arid climate. Similarly， the development and sedimentary evolution of multi-stage alluvial fans in the catchment of Nalinggele River constrains the lateral oscillation of the river and Li endowments in different salt lakes， resuting in differences of the sedimentary thickness and age of the salt deposits in the terminal salt lakes. The salt-bearing strata are thick in the east and west ends but thin in the middle， and the age of forming salt is old in the west and new in the east， while the Li resources are large in the east and small in the west. Therefore， the studies on the source-sink process of Li-rich brine deposits in the central QB and the hydrogeomorphic evolution of the Nalinggele River are benesit to reveal the salt formation of the terminal salt lakes and the spatially differentiated mineralization.