Abstract: With the rapid development of new energy vehicles and lithium batteries,lithium resources have become important strategic resource for many countries. However,the distribution of global lithium resources is uneven,and China′s lithium resource dependence on foreign countries is as high as 75%. There are abundant sedimentary lithium deposits to be developed, the mineralization characteristics and occurrence state of lithium restricts its separation,extraction and efficient development and utilization. This paper introduces the main types of global lithium resources and their characteristics,analyzes the temporal and spatial distribution characteristics and the formation of geological background of sedimentary lithium deposits,and argues that sedimentary lithium deposits have become an important type of new lithium resources in the world. Due to it has the advantages of large reserves,wide distribution and low exploitation cost,it shows great development value and broad utilization prospect. By summarizing and reviewing the research results of sedimentary lithium deposits at the present stage,three major characteristics are summarized :① sedimentary lithium deposits mainly divided into three types:volcanic clay type,carbonate clay type/ associated type and jadar type. They are mainly distributed in North America,South America,Europe and Asia. Its metallogenic age is mostly in the Cenozoic era,and part of the sedimentary lithium ore associated with bauxite and coal system was formed in the Paleozoic or Mesozoic era. ② Volcanic clay lithium deposits are mostly formed in the closed lake-phase sedimentary basin,the mineralization material mainly comes from volcanic magmatic activities. The main sources of lithium in Jadar- type lithium deposits are river sediments and volcanic eruptions in different periods. The lithium in carbonate clay-type/ associated lithium deposit mainly originates from the sedimentary environment,and its enrichment process is mainly related to weathering and sedimentation. ③ In volcanic clay type lithium deposit,lithium mainly occurs in Li-smectite,hectorite and illite; The mineral composition of carbonate clay type/ associated type lithium resources is different,and there are three types of lithium occurrence states:① occurs in the lithium chlorite interlayer hydroxide layer;② occurs in the illite structure octahedral or pseudohexagonal ring;③ occurs in the kaolinite structure octahedral. In Jadal type lithium deposits,lithium mainly exists in the crystal structure of the independent mineral Jadarite. Finally,this paper provides prospects for the research direction and exploitation prospects of sedimentary lithium resources in China,which provide support for geological exploration and efficient development of lithium resources in China.

Key words: sedimentary lithium deposit,clay minerals,lithium content,occurrence state