Basalt Genesis Analysis And Geological Relics In The Longwan Volcano National Geopark,Huinan County,Jilin Province

Longwan Volcano National Geopark in Huinan County,Jilin Province is a unique landform formed by explosive eruption of volcanic basalts.From the late early Pleistocene to the early Middle Pleistocene,the volcanic movement in this area was frequent and intense,which formed the unique volcanic topography and landform of Longgang Mountain and numerous crater lakes and volcanic cones,which became the unique tourist resources of the park.The Longwan Volcano National Geopark in Huinan County,located in the Longwan National Nature Reserve in Jilin Province and in the middle of the Longgang Mountains in Changbai Mountain,was designated as a National Geopark in April 2018.There are ten scenic spots in the park,which can be summarized as"seven bays","one waterfall"and"two tops".Volcanic landform structural denudation landform and erosion accumulation landform are three main landforms in the study area.Geologically,the study area is located at the margin of the North China platform and has the characteristics of typical strata of the North China platform.The strata exposed from the old to the new are archean and Cenozoic strata.Basalt in Longwan volcano national geological park,Huinan county,Jjilin province is characterized by low silicon?SiO₂=45.35wt%-50.50wt%?,alkaline enrichment?K₂O+Na₂O=5.16wt%-5.72wt%?,potassium quality?K₂O/Na₂O>0.5?and high aluminum?Al₂O₃ content13.25wt%-15.97wt%,Al₂O₃>K₂O+Na₂O+CaO?.In the TAS diagram,according to the bas alt boundary line,the rock samples are all alkaline basalts,and the sample data falls in the area of coarse surface basalts and basaltic coarse andites.On the chondritic meteorite standardized rare earth partition chart,the trace element test results of basalt in longwan geological park show a right-dipping curve,showing the characteristics of light rare eart h?LREE?enrichment and heavy rare earth?HREE?loss?La/Yb=12.130-24.169>1?.Mean while,it can be seen that the rare earth element fractionation degree is relatively large,and there is no abnormal Eu and Ce.Research area of geological relics are divided into group,volcanic crater lake landscape landscape,lava relics landscape,volcano clastic accumulation ruins landscape four types,and waterfalls,mineral spring group,volcanic wells and related basic types,the relevant type of geological relics landscape analysis of the description of the geological characteristics and genesis,and the corresponding scientific research value and efficiency value of evaluation.Longwan Volcano in Huinan County,Jilin Province has the largest group of volcanic lakes in China.