Introduction to Geology, Various Rx and Minerals

Basic Geology Geo- earth Study of processes that occur on surface or in the interior of earth Theory of Plate Tectonics Theory that earth is made of “plates” that move around on giant convection currents originating in the mantle Asthenosphere –upper gooey part of mantle

Density and Movement Crust comes in two forms: Oceanic: old, dense, heavy, cold – BASALT Continental: younger, less dense – GRANITE When they meet – density wins…

3 Types of Plate Boundaries Convergent: plates come together mountain building, volcanoes, earthquakes, Subduction of oceanic plate creates a trench Destructive ocean-continent or continent-continent

3 Types of Plate Boundaries Divergent: plates pull apart seafloor spreading creates new oceans mid-ocean ridges Constructive

3 Types of Plate Boundaries Transform: plates move past each other earthquakes San Andreas Fault AKA – strike- slip faults Conservative

Minerals The definition of a mineral: Naturally occurring (not man-made) Inorganic Solid (not made of liquid or gas) with a Repeating pattern with a Definite crystal structure

Different Crystal Patterns

Ways to ID Minerals Color – worst way to ID minerals – but still useful

Ways to ID Minerals Hardness – Moh’s Hardness scale

Rock Forming Minerals The most common rock forming minerals are composed of 8 elements: Oxygen (O), Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), Potassium (K) Iron (Fe) and Magnesium (Mg)

Mineral Resources Ore - rock that contains useful minerals that can be mined at a profit. Since 98% of the Earth's crust is made up of 8 elements, an element/mineral has to be concentrated at levels above normal for profitable mining.

Common Rock Forming Minerals

Minerals vs. Rocks There are nearly 4000 known minerals - but most rocks are formed by only a few dozen minerals. Rocks are aggregates or mixtures of minerals. So... minerals are the building blocks of rocks. How do minerals come together to form a rock? Hummmmmmm

Sedimentary Rocks Sedimentary rocks may be made of other rocks, by chemical reactions, or organic substances.

Igneous Rocks Ignis = fire in Latin Rocks that form underground from magma that cools and crystallizes.

Metamorphic Rocks Change of original rocks – sedimentary or igneous – to a new kind of rock due to heat and pressure Alter ego: metamorphic rock will have a sedimentary or igneous counterpart –

I’m Like You Only Different Sandstone (heat and pressure) = quartzite Shale (heat and pressure) = slate Limestone (heat and pressure) = marble Granite (heat and pressure) = gneiss