Geology Notes PDF
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These notes provide an overview of different types of rocks (metamorphic, igneous, and sedimentary) and their formation processes. The notes also discuss the rock cycle and the difference between rocks and minerals. Finally, the different geological eras are briefly introduced.
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**Metamorphic rocks** Rocks that form from other rocks under extreme heat or/and pressure. Formation: Contact metamorphism, where rocks around lavas recrystallise because of extreme heat ex: limestone to marble. Regional metamorphism, where rocks form under mountains with extreme heat and pressu...
**Metamorphic rocks** Rocks that form from other rocks under extreme heat or/and pressure. Formation: Contact metamorphism, where rocks around lavas recrystallise because of extreme heat ex: limestone to marble. Regional metamorphism, where rocks form under mountains with extreme heat and pressure ex: gneiss Examples: schist, quartzite **Igneous rocks** Rocks that form when magma/lava cools down. Formation: Intrusive igneous rocks, where magma cools underground. Properties: large crystals ex: granite Extrusive igneous rocks, where lava cools on the surface. Properties: small or nonexistent crystals ex: basalt or obsidian **Sedimentary rocks** Formation Clastic, where rocks get deposited, compacted, then cemented with minerals. Ex: sandstone Organic, where organic or biological material is compressed to create a rock. Ex: coal Chemical, where minerals dissolved in the air precipitate and recrystallize to form a rock. Ex: gypsum Rock cycle Igneous rocks\_deposition+erosion\_sedimentary rock\_heat+pressure\_metamorphic rock Igneous rocks erode and deposit to create sedimentary rocks; sedimentary rocks melt under pressure to create metamorphic rocks; metamorphic rocks melt and cool to create igneous rocks. **Rock vs mineral** A rock is a solid with an uneven distribution of multiple minerals, while a mineral is a solid with a single or multiple elements/compounds in an uniform crystalline structure. Rock ex: granite, mineral ex: feldspar **Crystal** A solid with an uniform atomic structure. Ex: quartz **Geological eras** Paleozoic, 541 to 252 million years ago, where water dwellers arrived and trees existed along with some land dwellers in the carboniferous period. Mesozoic, 252 to 66 million years ago-dinosaur and reptile era. Cenozoic, 66 million years ago to today-human era, Cambrian explosion for diverse organisms. **Types of metamorphic rocks**-foliated, with banding-ex schist, and non foliated-ex marble, without banding.
