1. Rocks

2.  Rocks are any solid mass of mineral or mineral-like matter occurring naturally as part of our planet.

3.  1. Igneous  2. Metamorphic  3. Sedimentary

4.  Igneous means “from fire”  Rocks that are formed by the crystallization of molten lava and magma.

5.  Rock that is formed from the products of weathering that have been transported, deposited, compacted, and cemented.  Generally the only type of rock fossils are found.

6.  Existing rock is changed deep within the earth by heat, pressure, and/or chemicals.

7.  At one point in time a rock has changed from one type of rock to another.  Rock continues through the rock cycle by the following:  Magma – molten material deep within the earth  Lava – Magma that reaches the earth’s surface  Weathering – process by which rocks are broken down by air, water, and living things  Sediment – weathered pieces of earth

9.  Heat within the earth forming both metamorphic and igneous rock  Weathering processes and movement of weathered materials are powered by the sun  External processes produce sedimentary rock.

10.  Intrusive  Formed when magma hardens beneath the earth’s surface. (Forms “In” the earth)  Characterized by large crystal formations due to the slow cooling process  Extrusive  Formed when lava cools and hardens. (forms on the “ext”erior of the earth)  Crystal size is greatly influenced by cooling times. ▪ Little to no crystals – very quick cooling ▪ Example: Obsidian and Pumice ▪ Large Crystals – slower cooling

13.  Texture  Glassy – Rapid Cooling ▪ Obsidian (Top Picture)  Porphyritic – Different rates of cooling, different sized crystal grains ▪ Bottom Picture  Composition  Granitic Composition – mostly made of light colored quartz and feldspar

14.  Basaltic composition rocks are made mostly of dark-colored silicate minerals and plagioclase feldspar.  Andesitic composition rocks are between granitic light-color minerals and basaltic composition dark- colored minerals.  Ultramafic composition rocks are made mostly from iron and magnesium- rich minerals. Basalt

16.  Weathering – Natural Processes that breakdown existing rocks into smaller fragments called sediment  Erosion – Weathering and removal of rock  Deposition – When an agent of erosion (wind, water, ice, or gravity) loses energy a drops sediment

17.  Compaction is a process that squeezes or compacts sediments  Cementation takes place when dissolved minerals are deposited in tiny spaces between sediments.

18. 1. Clastic Sedimentary – composed of weathered pieces of rocks and minerals  Classified by particle size  Examples: Shale, Sandstone, and Conglomerate

19.  Chemical sedimentary rocks form when dissolved substances precipitate, or separate, from water.  Common rocks include  Limestone  microcrystalline quartz like chert, flint, jasper, or agate  Evaporites such as rock salt or gypsum  Coal

21.  Metamorphism means “to change form”  2 types  Contact Metamorphism ▪ Magma moves into rock ▪ Changes because of increased temperature  Regional Metamorphism ▪ Large Scale deformation and high-grade metamorphism ▪ Occurs during mountain building ▪ Produces the greatest amount of metamorphic rock

22.  Heat  Provides energy to drive chemical reactions  Pressure  Cause more compact rock and greater density  Hydrothermal Solutions  Hot water-based solutions escaping from the mass of magma  Promote recrystallization by dissolving original minerals and then depositing new ones

23.  Foliated  Banded or layered appearance ▪ Example: Gneiss  Non-foliated  Does not have a banded texture ▪ Example: Marble