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).
Igneous rocks are classified according to their mineral content: 1  Ultramafic rocks are dominated by olivine and/or pyroxene. 2  Mafic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine.Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).There is little or no quartz. Felsic rocks are mostly feldspar (especially K-feldspar), at least 10% quartz, and less than 15% mafic minerals (biotite, hornblende).afic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine. Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).