Study On Size Characteristics Of Red Weathering Crust At Qidingshan In Dalian

Weathering crusts are discontinuous surface covering layer of bedrocks which experienced long-time physical and chemical revolution or consequences of correlation from external spheres of the earth.There are many kinds of weathering crusts widely distributed around the world because of the differences of rock properties and natural conditions like weathering crusts in tropical or subtropical areas.Grain size distribution is one of the important characteristics of weathering crusts,which has important implications for inferring geographical environmental,so it is widely used by studying on climate change,paleoclimate reconstruction and geology research as a important means.The paper conducts a preliminary research on geological features of Dalian through field investigation in order to find out the distribution and formation mechanism of red weathering crusts.This paper chooses Qidingshan profile as the object to research as a discussing to developing feature and degree by grain size analysis.It makes us to understand the climate and geology revolution which formed in long-time and provide many basic data to rich the research of red weathering crust.In today's world,environmental changes are currently hot social issues.The research of weathering crusts gives us a lot of helps for building and protecting environment which has the potential economic and social benefits.This paper select particle size analyzer LS13320 made by Beckman company in US to measurement,deal with data by MapInfo,Origin7.5,Excel.So major conclusions are as follows:At first,Qidingshan red weathering crust in Liaodong peninsula developed in carbonate rocks,it's consequence of long-time accumulation for carbonate mineral dissolution and acid insoluble.Red weathering crust formed on different background has different grain size distribution characteristics.In the long-time geological revolution,the grain size characteristics of granularity distribution frequency curves retained its relevant information.Second,in Qidingshan profile,the content of clay between 6.88%~10.54%,average index is 8.83%;Silt is mainly between 18.27%~36.88%,the average is 28.35%;sand grains ranged from 52.77%~52.77%,average value of sand grains content is 62.82%.The study show that grain size of it focuses on sand groups,the content of sand has not less than 50 %.Third,silt-clay ratio is between 2.66~3.50,with a mean of 3.18.In the whole profile,silt-clay ratio has a little higher.It shows that the degree of weathering is very low,and it increases firstly and then decrease.Fourth,the changes of the weathering crust degree,fluctuated,but the maturity ofweathering crust is not high.It may be related to environmental changes and water level fluctuation.Fifth,compared with Huaxi and Pingba profiles,the degree of weathering is higher than Qidingshan profile.So the climate condition of southern is more beneficial for red weathering crust to developing.