forensic pathology - the branch of medical science that uses medical knowledge for legal purposes; forensic pathology provided the evidence that convicted the murderer. forensic medicine. medical specialty, medicine - the branches of medical science that deal with nonsurgical techniques.
There are three major groups of rock: Igneous; Sedimentary; Metamorphic. They are all related through a continuous cycle called the rock cycle. Igneous rocks are created by melting and crystallization of molten material called magma. If the magma reaches the surface, the rocks are said to be extrusive. Volcanic lava flows are examples of extrusive igneous rocks.
When most people think of igneous rock they vision a volcano erupting pumice and lava. Igneous rocks form directly by crystallization from materials from a magma melt. Igneous rocks crystalize after the magma reaches the earth's surface. Igneous rock is divided into 2 groups, extrusive and intrusive. Extrusive rocks form when magma flows onto the surface of the earth or floor of the ocean through deep cracks or fissures and at volcanic vents, and then cools and hardens.