How are rocks different from minerals? Definition of Mineral: 1. Naturally occurring 2. Solid substance 3. Orderly crystalline structure 4. Definite chemical composition 5. Inorganic

Rocks Tell Stories Records of Geologic Past

1.Igneous rocks … from cooling and solidification of lava or magma 2.Sedimentary rocks … from compacted and cemented sediments, or chemical precipitates or evaporites 3.Metamorphic rocks … meta (change) morphic (form) … rocks changed by heat and pressure –but remain solid Rock Classification – 3 major groups based on their methods of formation or origin

ESRT – Page 6

Igneous- rocks that form when molten magma solidifies. Lava-magma that reaches the Earth’s surface. Magma-liquid rock deep within the Earth.

Intrusive- igneous rocks which form when magma solidifies deep underground.(plutonic) Extrusive- igneous rocks which form when lava cools rapidly at Earth’s surface. (volcanic)

Felsic-lava that is rich in silica, light in color and low density. Mafic-lava that is rich in iron & magnesium, dark in color, & high density FELSIC MAFIC

Texture-the size of the mineral grains or crystals. (glassy, fine, course) Porphyry- a rock that contains a mixture of various sized crystals.

Igneous Rocks

Types of Igneous Rock Type of Texture Where & How they cool

Type of Igneous Rock Where & how they cool Type of Texture

Sedimentary Rock Vocabulary Clastic – rocks made up of fragments of other rocks.Clastic – rocks made up of fragments of other rocks. Bioclastic- rock formed from the remains of living organisms.Bioclastic- rock formed from the remains of living organisms. Lithification- the process of forming a rock.Lithification- the process of forming a rock. Cementation- the process of sediments being stuck together by minerals in running water.Cementation- the process of sediments being stuck together by minerals in running water. Compaction-process in which air and water are squeezed out of sediments, forming a sed. rock.Compaction-process in which air and water are squeezed out of sediments, forming a sed. rock. Precipitation (from solution)- when water evaporates and leaves behind the minerals that were dissolved in the water.Precipitation (from solution)- when water evaporates and leaves behind the minerals that were dissolved in the water.

Hints/Clues to look for TYPES OF How they formed (method of lithification) Grain Sizes

Hints/Clues to look for How Formed (method of Lithification) Grain Sizes

Metamorphic Rock Vocabulary Recrystallization- the repeated process of melting and solidifying magma into crystals. Foliation- a metamorphic rock with visible parallel bands of minerals. Regional metamorphism- metamorphism that affects rocks over large areas at tectonic plate boundaries. (heat & pressure) Contact metamorphism-metamorphism of a rock due to the extreme heat of contact with magma.

Grain Size Type of Metamorphism Type of Texture

METAMORPHIC ROCKS Regional Metamorphism Foliated Coarse MEDIUM Fine Occurs over a very large area (thousands of Km’s) during tectonic activity. The movement of tectonic plates creates tremendous heat and pressure at plate boundaries causing the rocks to change Contact Metamorphism Nonfoliated Medium Fine Coarse Hot magma pushes through existing rock. The heat from the magma can change the structure and composition of the existing rock. Type of Metamorphism Type of Texture Grain Size