Washington, Mar 10: Earth scientists are reverting back into history and geography of the earth's crust to extrapolate what happened millions of years ago based on what they can observe now.
The scientists are concenrating their research on the formation of a fine grained metamorphic rock of the earth's crust called 'granulite'. The researchers decided to mathematically recreate the formation of granulite at various depths, to see if they could come up a method that mirrors the natural formation of the rock, Science Daily reported. By studying what were once pockets of hot, melted rock 13 kilometers deep in the Earth's crust 55 million years ago and calculating the period of cooling, the scientists were able to explain how granulite is formed as the molten rock migrates up through the crust.
Granulite, composed mainly of feldspars, has no residual water and is called metamorphic because it is formed in temperatures of greater than 800 degrees Celsius. It is a major component of the continental crust. Looking at the melting process is like looking at the process of the formation of continents, Andronicos explained.
''If you look over geologic time, not all the rocks are the same age, and the reason for that is they got formed at different times,'' he said.
''So if you can get a handle on the temperature, which is what controls melting and metamorphism, then you have a better idea of some of the fundamental controls that lead to rock formation, and therefore continents,'' he added.
The computer model, he said, will hopefully provide further insight into the energy balance of the Earth during crustal formation.