My very good friend Mark, has given me an excellent explanation which I will share with you.
The Earth's Original soil would have been volcanic ash that settled on the fiery and barely cooled crust and ash that remained suspended in the atmosphere. As the Earth contunued to cool, water vapour formed due to the chemical reactions caused by the static electricity storms that are thought to have existed at that time. As the temperature dropped even further there were violent rain storms which would have eroded the rock even more creating more soil.
At this point microbes and bacteria appear, either introduced from interstellar material like meteorites, or created locally. As the bacteria reproduced and died they produced what we might call the "organic" soil we know today. Plants are by far the best soil makers as they break down the rock and help build soil with their decaying matter.
Don't forget the contributions of the Glaciers either. As they flowed, so they gouged millions of cubic tons of rock out of the crust and ground it to a fine dust and are the reason that the bedrock is so close to the surface in some areas. Much of the natural beauty of the mountainside in areas like Scotland is down solely to the Glaciers.
So, there you have it, A Brief History of Dirt.
Thanks Mark! |
