Required Rocks & Famous rock formations

IGNEOUS ROCKS Formed when magma or lava cools & crystallizes INTRUSIVE (Plutonic): magma cools underground slowly  large,visible crystals GRANITE Feldspar, quartz, mica & hornblende PEGMATITE Quartz, feldspar, mica & muscovite

Intrusive Igneous Rocks GRANITE PEGMATITE

Yosemite – El Capitan 3,600 feet granite exposed by glaciers

Yosemite – Half Dome 8,900 feet of granite Other ½ carved away? 93% grade

Joshua Tree– skull rock granite

Joshua Tree– granite marbles

Shasta– Castle Crags Granite from remnant of plug dome volcano.

Intrusive Igneous Rock magma can penetrate rock Horizontally  SILLS Vertically  DIKE INTRUSION ROCKS are rocks that have been “disturbed” magma

Devil’s Tower, WY Igneous intrusive rock in sedimentary rock Thought to be a volcanic neck or plug, exposed by erosion

Devil’s Pipes– CA

Los Arcos, Cabo San Lucas intrusive igneous rock worn away by waves

IGNEOUS ROCKS EXTRUSIVE (Volcanic): lava cools above ground rapidly no visible crystals OBSIDIAN Silicon & oxygen BASALT Feldspar,pyroxene, & olivine PUMICE Silica & feldspar

Extrusive Igneous Rocks OBSIDIAN BASALT PUMICE “glassy” black & forms bedrock gas trapped as it cools

Columbia River Flood Basalts, OR

Shiprock, New Mexico Basalt volcanic neck  erosion

SEDIMENTARY ROCKS Rock form from sediments or organic material CLASTIC: formed of large or small sediments cemented together CONGLOMERATE - particles cemented SANDSTONE- quartz, feldspar, & calcite SHALE - feldspar, quartz, mica LIMESTONE- calcite (coral, shells) DIATOMACEOUS EARTH – calcite (diatoms)

Clastic Sedimentary Rocks CONGLOMERATE SANDSTONE SHALE 2 mm or larger sand 1/16 – 2 mm mud less than 1/256 mm

Clastic Sedimentary Rocks LIMESTONE DIATOMACEOUS EARTH

Arches, Utah Sandstone built above salt beds combined with wind erosion  arches

Beehive, Utah

Chimney Rock, Colorado Sandstone worn by erosion

“Finger to God”, Africa

Mono Lake Tufa river carries calcium into lake which reacts with carbonates in lake  limestone

“Diatomaceous Earth”, Hat Creek “chalk like“rock that crumbles into powder. fossilized diatoms (algae) used in tooth fillings, pool filters, cat litter

SEDIMENTARY ROCKS NON-CLASTIC: made from minerals or living things “ORGANIC” CAVE DEPOSITS “dripping” limestone PETRIFIED WOOD Fossilized wood – manganese, iron & copper COPROLITE Fossilized animal dung – calcium, phosphorous & quartz

Non-Clastic Sedimentary Rocks CAVE DEPOSITS PETRIFIED WOOD COPROLITE

Shasta Caverns

METAMORPHIC ROCKS Rocks changed by heat or pressure MARBLE - changed from limestone SLATE - changed from shale MICA SCHIST - changed from pegmatite QUARTZITE - changed from sandstone GNIESS- changed from granite

Metamorphic Rocks MARBLE SLATE MICA SCHIST QUARTZITE GNEISS

Sierra Nevada Mtns

Marble Canyon, Death Valley