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.
The oldest continental rocks are found in what we call cratons. A craton is a stable part of the continental lithosphere, which has survived several cycles responsible for the merge and the dislocation of supercontinents. Cratons are therefore always found within continents. Some cratons in Canada and Greenland shelter the oldest continental rocks in the world, about 4 billion years old. Other cratons in South Africa, Australia and Asia have 3 billion years old continental rocks. The oldest seafloor is comparatively very young: about 280 million years old. It is found in the Mediterranean Sea and is a remnant of an ancient ocean that is disappearing between Africa and Europe.