United States invasion of Panama Reference: Wikipedia The United States Invasion of Panama, code-named Operation Just Cause, was the invasion of Panama by the United States in December 1989. It occurred during the administration of U.S. President George H. W. Bush, and ten years after the TorrijosâCarter Treaties were ratified to transfer control of the Panama Canal from the United States to Panama by January 1, 2000.
Ultramafic (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica Mg O, high Fe O, low potassium, and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content).
Ultrabasic rocks are composed of less than 45% silica and contain no quartz or feldspar. They are composed mainly of the minerals olivine and pyroxene. The most common ultrabasic rock is periodite. Periodite is a dark green, coarse-grained igneous rock that many scientists believe is the main rock of the mantle.Basalts are dark colored, fine-grained extrusive rock.ost basalts are volcanic in origin and were formed by the rapid cooling and hardening of the lava flows. Some basalts are intrusive having cooled inside the Earth's interior. Granite is an igneous rock that is composed of four minerals. These minerals are quartz, feldspar, mica, and usually hornblende.