Color a The overall lightness or darkness of a rock is a valuable indicator of its makeup. a Light-colored rocks are Quartz. Feldspar. Muscovite Dark-colored rocks are Biotite Amphibole Pyroxene
Color ◼ The overall lightness or darkness of a rock is a valuable indicator of its makeup. ◼ Light-colored rocks are: ◼ Quartz. ◼ Feldspar. ◼ Muscovite. ◼ Dark-colored rocks are: ◼ Biotite. ◼ Amphibole. ◼ Pyroxene
Intrusive( Coarse-grained) gneous Rocks (1) Granite is quartz-bearing rock in which potassium feldspar is at least 65 percent by volume of the total feldspar present a Granodiorite is quartz-bearing rock in which plagioclase is 65 percent or more of the total feldspar present
Intrusive (Coarse-grained) Igneous Rocks (1) ◼ Granite is quartz-bearing rock in which potassium feldspar is at least 65 percent by volume of the total feldspar present. ◼ Granodiorite is quartz-bearing rock in which plagioclase is 65 percent or more of the total feldspar present
Fine-grained Rhyolite Dacite Andesite Basalt Coarse-grained Granite Granodiorite I Diorite Gabbro Peridotite Calcium-rich 9 Plagioclase 0E Sodium-rich Potassium feldspar Olivine Biotite 20 Muscovite Amphibole 9o Color of rocks becomes increasingly dark Increasing silica content Naming igneous rock
Naming Igneous Rock
Intrusive(Coarse-grained) Igneous Rocks(2) Granitic rocks include both granite and granodiorite Granitic rocks are only found in the continental crust Granitic magma forms when continental crust is heated to its melting temperature The most common place where such high temperatures are reached is in the deeper portions of mountain belts formed by the collision of two masses of continental crust
Intrusive (Coarse-grained) Igneous Rocks (2) Granitic rocks include both granite and granodiorite. Granitic rocks are only found in the continental crust. Granitic magma forms when continental crust is heated to its melting temperature. The most common place where such high temperatures are reached is in the deeper portions of mountain belts formed by the collision of two masses of continental crust
Intrusive(Coarse-grained) Igneous Rocks ( 3) Diorite The chief mineral in diorite is plagioclase a Either or both amphibole and pyroxene are invariably present. a Forms in the same way as granite and granodiorite. a It is found only in continental crust
Intrusive (Coarse-grained) Igneous Rocks (3) ◼ Diorite: ◼ The chief mineral in diorite is plagioclase. ◼ Either or both amphibole and pyroxene are invariably present. ◼ Forms in the same way as granite and granodiorite. ◼ It is found only in continental crust