Characteristics Of Red Weathering Crust Development In Southern Liaoning

There are different kinds of weathering crusts distributed and developed all over the world,such as red weathering crust in tropical or subtropical area.Weathering crusts are consequences of interacting from factors like lithosphere,hydrosphere,atmosphere and biosphere or layer of bedrocks composed by residue particles,new developed chemical residues after bedrocks' weathering.Red weathering crust is mainly distributed in south area of China,while weathering crust was only revealed in Liaodong peninsula and Shandong peninsula,other kinds of weathering curst was covered with loess layer.Researching red weathering crust in Liaodong peninsula can extent scope of researching into Liaodong peninsula area and it has important significance of dividing north border of tropical area in Tertiary.This thesis chooses the southern of Liaoning as object of research.We performed discuss to developing feature,the process of profiles revolution of red weathering crust in north area by particle size feature?geochemical feature?pH?feature of quartz particles.Make contrast with weathering feature,particle size feature and geochemical feature of weathering crust in south area,then we can conclude as follows:Firstly,the components of clay class in Shicao profiles ranged from 7.25%?20.71%,average coefficient is 13.26%.Silt-clay ratio ranged from 2.93%?6.67%,average coefficient is 4.83%.Components of clay in Qidingshan ranged from 5.29%?6.03%,average coefficient is 5.65%,silt-clay ratio ranged from 5.5%?7.71%,average coefficient is 6.25%.Triangle configuration of particle size components in Shicao illustrated that particle size of profile were assembled in corner between silt and coarse sand,the sampling spots were mainly distributed among silt-clay area with tendency of accumulation to silt size area.The triangle configuration of particle size distribution in Qidingshan area illustrated that components of clay takes a smaller part in whole profile while component of clay size in most samples were lower than 10%,it has higher component of coarse sizes.Scatter diagram of particle size in Shicao and Qidingshan profile illustrated that two profiles has uniformity with underlying bed rocks,particle size is mainly distributed in coarse size class.Low thick-weathering curst,low-component-clay size,higher silt-clay ratio and particle size assembled in coarse size class illustrated that red weathering crust in the southern of Liaoning is remain unmatured in developing.Secondly,content of silicon in all two profiles are high,as 50%or over,content of Al?Fe are lower.Normal elements like Si?Al?K?Na?Ca?Mg appears eluviation feature in Sicao profile,elements like Si?A1 appears concentration apparently,whereas,elements like Na?Mg appears apparent eluviation feature,which is reflected by these two element's strong eluviation.What we can conclude from tendency of CIA,eluviation feature and transposition coefficient is that change of Sicao profile were apt to be identical,which can be described as consequence of Ca?K eluviation and Al concentration except some profiles may be effected by structrual movement and underground water with some potential alien material interruption.From all of this we can discriminate weathering curst is consequence of bedrock's weathering effect,or as consequence of transformation from local bedrocks.Feature curve of eluviation coefficient,relative fitness of transposition ratio also shows graduality from bedrocks to weathering crust,which indicates revolution progress of weathering curst developing as climate change.Thirdly,mineralogy indication?chemical weathering indication and clay content appears apparent waving in whole profile and it didn't show revolution features of weathering effect became stronger from bottom to top.There appears an apparent low stage of weathering curst developing at the mid-down part,which has lower than 10%,clay particles and its coarse size has reached or exceed 50%;CIA?Ba and K/CN(K2O/(CaO*+Na2O))has appeared some abnormal in this area.The reason why this phenomenon appears are:1.Change of weathering condition at the process of weathering vanguard.2.Underground water's waving level effects weathering profile.The red weathering curst developed in Sicao area was developed since Tertiary that is far from now.At the long process of geological revolution,waving of paleo underground water and weathering condition would occur rapidly.Rock-soil border is exemplified as an important border of geochemical weathering.At the process of weathering vanguard's weathering,the change of weathered condition can effect weathing process in certain layer and causes weathering index waving in profile.From the view of the trend of the change of the profile,the weathering crust formed early in the hot and humid climate,and then experienced a relatively long period of r low temperature and drying period.At the end of the weathering crust formed,the climate turned into high temperature and high humidity.In addition,if a developed profile was effected by underground water waving later,it also would effect contents of profiles in certain area.In conclusion,change of weathering condition and underground water waving makes tendency of red weathering crust revolution more complex by transformation and composition to developed profiles.Fourthly,as for red weathering crust in the southern of Liaoning,although there exists underground water transformation and weathering differentiation at the process of carbonate acid bedrock that caused coefficient waving,there also exists stronger tendency from bottom to top.From low frequent susceptibility amplifying and lower pH shows that strongth of weathering crust developing descends as depth becomes deep,which is coincidences with shorter time of weathering as profile became deeper.Fifthly,underlying bedrock in Qidingshan and Shicao are all limestones,clay particles in Qidingshan are lower than Shicao profile,silt-clay ratio is higher than Shicao profile.Contents of SiO2 in Shicao profile are lower than Qidingshan profile but contents of Al2O3 and Fe2O3 more in Qidingshan profile,which indicates Al?Si eluviation effects are better than Shicao profile.We can only see thick soil layers at the top of Quaternary loess profile covered in Qidingshan profiles.Profound loess layer interrupted water penetration,so after crust was developed,moisture content condition in Shicao profile is better than profile in Qidingshan,weathering effect in Sicao profile is better than Qidingshan profile,weathering effects of Qidingshan area is lower than profile in Shicao profile.Sixthly,Quartz particles found in Shicao profile.It maybe come from weathering residue of the Shale and slate which inclusion in limestone.Macrograph features of quartz samples sized from Shicao profile has shape features of rocks particles or residues scattered by bedrocks' weathering effect.Most of quartz samples appears structrual features in surface composed by SiO2 corrosion and deposition under high-energy chemical environments.Quartz particles in mid-up layer has been shattered completely,which has experienced long-time geological revolution.Most of quartz particles have been scattered and erosion in mid-up layer.Erosion and deposition of SiO2 of incomplete decomposition quartz are stronger than quartz particles from down part of samples.Seventhly,contents of clay particle in Shical profiles are lower than Huaxi and Pingba profiles,average CIA coefficient of Huaxi and Pingba profile are all over 85,while the average coefficient in Shicao profile is lower than 85;S/A ratio in Sicao are higher than Huaxi and Pingba profiles.We can conclude from clay contents?CIA?S/A differenciation that climate condition of weathering crust development is lower than south area.The developing weathering degree and weathering crust maturity of north area are all lower than south area.