Thursday, July 26, 2012
This is what I think I know. The estimated age of the earth is 4.3 billion years old. The composition of the current earth crust is mostly sedimentary and metamorphic which leads me to believe that the current mantel has accumulated over time through the processes of erosion. The locally observable geology is amazing to me because it is composed of layers of very distinct rock and soil types exposed by erosion. Then supposedly through plate tectonic actions caused those sedimentary and metamorphic slabs to be pushed upward where erosion, once again, reduces them to mole hills and the process recycles itself maybe as many as 12 times. That is how often the tallest mountain in the world would be eroded if it lost one inch per thousand years in height.