Physical Properties of different types of Igneous Rocks (Geology)

Physical Properties of different types of Igneous Rocks (Geology)

• 1.
  Soran University Faculty ofEngineering Petroleum engineering department Igneous rock Prepared by : Raboon Redar Supervised by : Mr. Arkan Mansur Nidhal 2019
• 2.
  1 Igneous rocks (fromthe Greek word for fire) form from when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. Intrusive Igneous Rocks: Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth. Great globs of molten rock rise toward the surface. Some of the magma may feed volcanoes on the Earth's surface, but most remains trapped below, where it cools very slowly over many thousands or millions of years until it solidifies. Slow cooling means the individual mineral grains have a very long time to grow, so they grow to a relatively large size. Intrusive rocks have a coarse-grained texture. Extrusive Igneous Rocks: Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth's surface. These are the rocks that form at erupting volcanoes and oozing fissures. The magma, called lava when molten rock erupts on the surface, cools and solidifies almost instantly when it is exposed to the relatively cool temperature of the atmosphere. Quick cooling means that mineral crystals don't have much time to grow, so these rocks have a very fine-grained or even glassy texture. Hot gas bubbles are often trapped in the quenched lava, forming a bubbly, vesicular texture.
• 3.
  2 Rock name Texture Color Mineral composition Intrusive Extrusive Equivalent Felsic or mafic GranitePhaneritic Gray and black Orthoclase, quartz, plagioclase, micas, amphibole Intrusive Rhyolite Felsic Basalt Aphanitic Brown white grey Plagioclase, pyroxene, micas, amphibole, olivine Extrusive Gabbro Mafic Gabbro Phaneritic Greenish or dark Plagioclase, pyroxene, micas, olivine Intrusive Basalt Mafic Rhyolite Aphanitic Pink Orthoclase, quartz, plagioclase, micas, amphibole Extrusive Granite Felsic Obsidian Glassy Black - - - - Peridotite Phaneritic Dark colored brown and grey Olivine, pyroxene Intrusive - Ultramafic Pumice Vesicular Grey Orthoclase, quartz, plagioclase - - Felsic and intermediate Diorite Phaneritic Speckled black Orthoclase, quartz, plagioclase Intrusive Andesite Intermediate Andesite Aphanitic Bluish grey Plagioclase, amphibole, pyroxene Extrusive Diorite Intermediate Pegmatitic Pegmatitic Pink Orthoclase, quartz, plagioclase Intrusive - Felsic