Primitive rocks of the earth slowly evolved with relatively cool temperature.
Explanation:
The oldest rocks of the earth have been broken down by the process of the erosion and have been estimated to be more than 4 billion years old and were formed during the hadeon eon.
When the surface of the earth was exposed at various places such as the geologic shields and is younger than the age of the earth and formation of the universe some 4.5 billion years ago as mineral contents shows of the late crystallization of magma.
I would say that the US and the Soviet Union at the end of WWII withdrew their troops as soon as a demilitarized zone was created. Also, I am sure they would require a peace treaty to be signed with Germany before withdrawing troops.
