The process of changing over time, on many scales, by which novel lifeforms come to exist and to diverge from previously-existing lifeforms. A more in-depth exploration of this vast biological subject can be found in the Evolution Wing of the UCMP 's Online Exhibit Halls. Because of the difference in temperature between the hot interior and relatively cool exterior of the earth, the molten materials cool rapidly. Very fine crystals, characteristic of this type of rock, form as a result of the sudden cooling. A planar break in or between brittle rocks.
Faults can range in length from a few centimeters to many kilometers.
While faulting can have many causes, much of it occurs at places of weakness in the crust , such as plate boundaries. Faults often occur in groups or branched systems, with forces and motion distributed among them. For this reason, it is often useful to refer to a fault zone , a region in which faulting is present, instead of thinking of faults in isolation. The IRIS Consortium website has good animations of these three types of faults and the motion that occurs along them. The remains of ancient plants or animals preserved over time by their natural surroundings.