AGE OF EARTH 

2-ON THE BASIS OF EROSION

      Some scientists have attempted to calculate the age of the earth on the basis of the rate of erosion of the land areas. This method is based on this belief that the continental areas are regularly eroded by the exogenous or denudational processes every year. If we can find out the total amount of denudation of the surface materials till now and the annual rate of denudation, then the age of the earth can be estimated. It has been generally believed that one-foot thick surface of the earth  is generally eroded down in about 10,000 years. It is also true that the eroded sediments are deposited by the fluvial processes as sedimentary rocks. The known thickness of sedimentary rocks is about 100 miles (528,000 feet) . Thus based on above facts the following calculations can be made

1 foot erosion = in 10,000 years

528,000 feet erosion = in 5280 million years.

(100 miles)   (5.28 billion years)

If we take the age of the earth to be double of the age of the thickness of deposited sediments derived through continuous of denudation of land areas, and then the age of the earth may be estimated at 10,560 million years. This method is also erroneous. because the rate of erosion of surficial material is affected by such a host of environmental factors, so it varies both spatially and temporally. Itis very difficult to determine the rate of erosion