The muscle may remain tender for up to 24 hours after a leg cramp. Leg cramps usually occur when you are resting-most commonly at night when in bed. (They are often called night cramps.) They may wake you. It can become a distressing condition if your sleep is regularly disturbed. leg cramp is a pain that comes from a leg muscle. It is due to a muscle spasm, which is when a muscle contracts too hard. It usually occurs in a calf muscle, below and behind a knee. The small muscles of the feet are sometimes affected.
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core. A typical anticline is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge.
In all cases, the measured ages provide only a minimum age for the Earth. So far, rocks older than 3.0 billion years have been found in North America, India, Russia, Greenland, Australia, and Africa. The oldest rocks in North America, found in Minnesota, give a U-Pb discordia age of 3.56 billion years (Figure 5). The oldest rocks yet found on the Earth are in Greenland, South Africa, and India. The Greenland samples have been especially well studied.