Analysis Of Geochemical Elements And Quartz Particle Surface Characteristics Of Red Weathering Crust In Dalian Area

The weathering crust is the product of the interaction between the atmosphere,hydrosphere,lithosphere and the biosphere.Changes in the content of chemical elements in the red weathering crust,changes in the geochemical indices,and the analysis of the surface characteristics of the quartz grains are important evidence for indicating the source of matter and the evolution of the ancient environment.In this essay,I will take the red weathering crust of coastal gardens in Changxing Island of Dalian and the red weathering crust of Huangnigou in Shihe town of Jinzhou city as research objects,through qualitative description and quantitative analysis to explore the characteristics of geochemical elements and surface characteristics of quartz grains of red weathering crusts,meanwhile,to infer the source conditions of red weathered crusts and the climate evolution process.The ZSX Prinmus II type X-ray fluorescence spectrometer from Japan is used to test the chemical elements of the red weathering shell,the oxide content of the Huangnigou is dominated by SiO₂?Al₂O₃ and Fe₂O₃.The sum of these three contents is 82.57%,and the contents of other major elements are K₂O>MgO>TiO₂>CaO>Na₂O,the average content of trace elements is MnO>SO₃>P₂O₅>Cr₂O₃>SrO>Rb₂O>NiO>ZnO>CuO.The SiO₂?Al₂O₃ and Fe₂O₃ are also the main oxides in the coastal garden.The sum of these three contents is81.81%.The other main elements are K₂O>MgO>CaO>Na₂O>TiO₂,the average content of trace elements is SO₃>MnO>P₂O₅>Rb₂O>Cr₂O₃>SrO>NiO>ZnO>CuO.The average value of CIA in the coastal garden profile is 71.75,and the average value of CIA in the Huangnigou profile is 82.29,the average value of the leaching index in the Huangnigou profile is 0.372,and the R² in the regression analysis of the CIA value and the leaching index ba value is0.6017.The surface characteristics of quartz particles are scanned by SEM,it is observed that the grain diameter of the quartz in the Huangnigou is smaller than that of the coastal garden,and the secondary grain of the Huangnigou accounted for 96.67%of the whole grain.The quartz grains in the coastal garden profile accounted for 86.7%of the sub-angular shape,and also contained 13.3%of sub-round quartz particles.The mechanical characteristics of the surface development of quartz grains in the red weathering crusts of the Huangnigou and the coastal garden mainly include conchoidal fractures,straight or curved impingement trenches,V-shaped impact craters,parallel cleavage planes,parallel steps,scratches and nicks,parallel lines,cracks,curved ridges,rolled lamellae,abrasion fatigue,and under-polishing surfaces etc;chemical generative features include scaly exfoliation,pits and pits,directional pits,siliceous spheres,siliceous scales,siliceous films and crystal growth etc.By analyzing the characteristics of chemical elements,geochemical indexes and surface characteristics of two weathered crust profiles in the Huangnigou and the coastal garden,it is found that the climate of the weathering crust is warmer and wetter,and is suitable for the development of red weathering crust.By comparing the main elements,CIA values and the surface features of the two sections,it is found that the mature degree of the red weathering crust of the Huangnigou is higher,and the maturity of the coastal garden section is low.