Igneous Rocks: Formation, Types, and Classification PDF

## The Rock - **rock** - natural substance composed of solid crystals of different minerals that have fused together. - **mixture & minerals fused together** - **Ex:** D Grant - وردي - orthoclise - أسود - Maica - **Types of the rock** - **Igneous rocks** - **Sedi...

## The Rock - **rock** - natural substance composed of solid crystals of different minerals that have fused together. - **mixture & minerals fused together** - **Ex:** D Grant - وردي - orthoclise - أسود - Maica - **Types of the rock** - **Igneous rocks** - **Sedimentary rocks** - **Metamorphic rocks** ## Igneous Rock - Rocks that formed through cooling and solidification of molten rock. - **molten rock** -> **Cooling** -> **Igneous rock** - **primary rock** - because it is the first type of rock that formed on Earth. - **magma** - very hot liquid formed in deep and high pressure and temperature. Parent material of igneous rock. - **Lava** - flow on the surface - **magma** - beneath the surface below - **molten rocks** - **volatile** - found in low amount, but it is important in the construction of raw materials. - **H2O - CO2 - F - Cl - Br** - **non-volatile** - - **SiO2(7) - Al - Fe - Ca - Na - K - Mg** - **acidic** - **basic** - **crystallization** - the combination of an acidic oxide with a basic oxide. - **acidic magma** - **basic magma** - **Acidic magma** - "Felsic minerals" rich in Feldspas. Non-ferromagnesium silicate (xFe-Mg). - **rich SiO2 - Na - K** - **poor Fe - Mg - Ca** - **light colour** - **high viscosity** - **acidic magma** -> **cooling** -> **acidic igneous rock** - **Basic magma** - "Malic minerals" ferro -magnesium silicate. - **rich Fe - Mg - Ca** - **poor SiO2 - Na - K** - **dark colour** - **less viscosity** - **basic magma** -> **cooling** -> **basic igneous rock** -> **ultra basic igneous rock** ## Classification of Igneous Rocks - **Occurrence/Origin:** - **Volcanic igneous rock** -> **cooling** -> **Lava** - **Hypobyssal igneous rock** -> **cooling** -> **magma** -> **cooling** -> **Plutonic igneous rock** - **Hypabyssal/Plutonic** - **intrusive rock** - **Volcanic** - **extrusive** - **Plutonic** - coars grains, crystalline igneous rock formed by the consolidation of molten rock material or magma beneath the Earth's surface. - **Hypabyssal** - Ig intrusive rocks that crystallized at intermediate depths. Resulting in medium grain size and textures. - **Volcanic** - a rock formed from lava erupted from volcanoes and solidified on or near the surface. ## The Difference - **Location** - **Temperature** -> **cooling rate** - **Crystal size** ## Texture - **Factors of crystal size:** - amount of dissolved gasses - cooling rate - **temp ↑ cooling rate ↓ size ↑** - **Texture** - shape - size - appearance of mineral grained. ### Plutonic - **Pegmatitic texture** - formed in the final stages of crystallization of magma rich in water vapor and gases. - **very coarse** - **Coarse grained texture** - **very coarse** - **cooling rate is slow** - **Ex:** Granite ### Volcanic - **Fine grained texture** - "دقيق الحبيبات" - **size is small** - **Ex:** Bazalet rock - **Glassy texture** - **no crystal** - **very rapid cooling** - **Ex:** Obsidian - **Vesicular texture** - **evaporation of gases from magma during crystallization** - **Ex:** Pumice - Scona - **Amygdaloidal texture** - deposition of magma in voids. - **Trachytic texture** - - **coarse grained** - **liquid magma** - **rearrangement** -> **tabular grained (phenocryst)** - **find (grand mass)** ### Hypabyssal - **Medium grained texture** - **Porphyritic** - **Volcanic** - نبرد فوقه سطح الارض - **ground mass (Srind)** - **phenocryst Coarse** - **Hypabyssal** - نبرد تحت سطح الأرض - **ground mass (sanct)** - **phenocryst Coarse** -> **medium** ## Chemical Compostion ### Acidic - **Felsic/non ferromagnesium silicate** - **Si 65 - 80** - **rich (kFeldspar - Naplagi - mica - Qiz)** - **high viscosity** - **low density** - **light colour except 10% dark** - **Ex:** Granite - Rhyolite - **Feldspar** - **Na** - **acidic** - **Ca** - **basic** - **K** - **acidic** ### Intermediate Rock - **Si 52 - 65** - **colour: dark - light** - **Biotite** - **Pyroxene** - **Amphibole** - **Ex:** Andesite - Diorite ### Basic - **Malic rock - ferro magnesiam silicate** - **Si 45 - 52** - **rich olivine. Pyroxene - Ca plagi** - **dark colour** - **high density** - **Ex:** Basalt - Gabbro ### Ultra Mahic rock - **Si < 45** - **rich (olivin - pyroxene)** - **Ex:** Peridotite ## Mineralogical ### Felsic - **non Ferromagnesiam** - **Qtz** - **Feldspar** - **SiO2 - K - Na** ### Mohic - **Perro Mg** - **Olivin** - **Pyroxene** - **Amphibole** - **Biotite** ## Bowen's Reaction Series - ***discountinuous*** - different in chemical composition and crystal structure - ***continuous*** - same crystal structure "Tricline" - **acidic** - **Albite** - dark - low T - **K-Feldspar** - **Muscovite** - **Quartz** - **intermediate** - **Biotite (mica)** - **Amphibale** - **Pyroxene** - **basic** - **Olivine** - **Na-Plagi** - **Na-ca-Plagi** - **Ca-Na-plagi** - **Ca-plagi** - light color - high T