GEOLOGICAL GEOMORPHOLOGY AND CHRONOLOGICAL CHARACTERISTICS OF LEIQIONG VOLCANIC AREA
In order to deeply understand the Leiqiong volcanic area,the relevant research done by the predecessors in the Leiqiong area was collected,and the volcanic geological features and chro-nology characteristics of the area were summarized.The data show that the Leiqiong area is affected by plate movement and mantle plume activity,and is controlled by three groups of NW,NE and EW fault zones,with strong volcanic activity.The Leiqiong depression basin was formed between the EW Huangpo-Jiepao fault zone in Leizhou Peninsula and the EW Wangwu-Wenjiao fault zone in northern Hainan Island.There are a large number of basic basalt eruptions in the basin.The volcanic activi-ties in Leiqiong area are characterized by multi-stage,multi-cycle and migration.There are three types of volcanism:explosive facies,effusive facies and effusive-sedimentary facies,forming volcan-ic landform types such as lava platform,volcanic cone,Maar lake,volcanic dome and lava tunnel.The magmatic activity in Leiqiong area began in the late Oligocene,which was the most extensive in the Pleistocene,and then the volcanic activity declined and ended in the Holocene.The previous ge-ochronological data of the Leiqiong volcanic area obtained by K-Ar,Ar-Ar,thermoluminescence and 14C dating methods show that the age range of the volcanic rocks in the area is between 34.78 and 0.01 Ma,and the volcanic activity is divided into six stages:Oligocene-Miocene,Pliocene,Early Pleistocene,Middle Pleistocene,Late Pleistocene and Holocene.