<P> Geology (from the Ancient Greek γῆ, gē, i.e. "earth" and - λoγία, - logia, i.e. "study of, discourse") is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time . Geology can also refer to the study of the solid features of any terrestrial planet or natural satellite, (such as Mars or the Moon). </P> <P> Geology describes the structure of the Earth beneath its surface, and the processes that have shaped that structure . It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks . By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth . Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates . </P>

Many geologic processes and events are due to what