PreQuiz Describe the strength of bonds between atoms in a solid. What is a mineral? True or False: Only eight elements make up the bulk of the minerals found in Earth’s crust. What is the most common mineral group? carbonates b. silicates c. oxides d. halides What are rock-forming minerals? What are some common properties of minerals?

3.1 The Rock Cycle rock- any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet Mixtures of minerals and sometime nonmineral material 3 major types of rocks: Igneous Sedimentary metamorphic

Rock Cycle

Summary Questions Use your own words to describe the sequence of processes that result in igneous rocks. Describe a specific example of a sedimentary rock becoming an igneous rock. Use your own words to describe the sequence of processes that result in sedimentary rocks. Describe a specific example of a sedimentary rock becoming a new type of sedimentary rock. Use your own words to describe the sequence of processes that result in metamorphic rocks. Describe a specific example of a sedimentary rock becoming a metamorphic rock.

Igneous Rocks Formation Intrusive Igneous Rocks Rocks that form when magma hardens beneath Earth’s surface Magma- molten material below earth’s surface Extrusive Igneous Rocks Rocks that form when lava hardens on Earth’s surface Lava- molten material on or above earth’s surface granite rhyolite

Texture of Igneous Rocks Igneous Rocks are classified by texture and composition Textures Coarse-grained- slow cooling results in large crystals Fine-grained-rapid cooling results in rocks with small, interconnected mineral grains Glassy- cools so quickly that ions cannot arrange themselves into a network of crystals Glassy does not mean they look glassy!!! (pumice) Porphyritic- rocks experience different rates of cooling, so they have different sizes of crystals in the same rock

Igneous Textures Fine-grained Coarse-grained Glassy Porphyritic

Examples of Igneous Rocks 1. Granite 2. Rhyolite 3. Gabbro 4. Basalt 5. Obsidian 6. Pumice

Sedimentary Rocks Formation (5 major processes) Weathering- breaks rocks into sediments Sediments- smaller pieces of rocks and minerals Erosion- movement of sediments Agents: water, wind, ice, or gravity Deposition- dropping of sediments because agent lost energy Compaction- squeezing or compacting of sediments Cementation- dissolved minerals are deposited in the tiny spaces among the sediments

Classification of S.R. Classified according to the way they form Clastic sedimentary rocks- made of weathered bits of rocks and minerals Grouped according to the size of the sediments Conglomerate- rounded, gravel-size or larger Breccia- angular Chemical sedimentary rocks- forms when dissolved minerals precipitate from water solutions

Features of S.R. The many unique features of sedimentary rocks are clues to how, when, and where the rocks formed Layers show the order in which the rocks formed Fossils hidden in sedimentary rocks show evidence of past life forms Ripple marks and mud cracks

Examples of S.R. Conglomerate Breccia Sandstone Limestone Rock salt

Metamorphic Rocks Metamorphism- to change form Formation Agents Changes occur at elevated temperatures and pressures Conditions are found a few kilometers below Earth’s surface and extend into the upper mantle Agents Heat- provides energy needed to drive chemical reactions, which may cause minerals to recrystallize Pressure- may cause the spaces between mineral grains to close or cause the mineral to recrystallize Hydrothermal Solutions- hot water solutions promote recrystallization by dissolving original minerals and then depositing new ones

Classification of M.R. Classified by texture and composition Texture Foliated-rocks with layered or banded appearances Formed when rocks undergo intense pressures causing the rock to be more compact or even recrystallize the rock Nonfoliated- rocks without banded appearances Contain only one mineral

Contact vs. Regional Contact Metamorphism Regional Metamorphism When magma intrudes rock Produces low-grade metamorphism = minor changes Ex: Marble Regional Metamorphism During mountain building, rocks are exposed to extreme pressures and temperatures Produces high-grade metamorphism = intense changes

Examples of M.R. Parent rock- original rock before metamorphism takes place Metamorphic Rock Parent Rock Slate Shale Gneiss Schist, Granite Marble Limestone Quartzite Sandstone Schist Phyllite Anthracite Bituminous Coal