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 PUMICEBASALT

“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 SHALESANDSTONE

2 mm or larger

mudless than 1/256

mm

sand1/16 – 2

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

PETRIFIED WOOD

COPROLITECAVE DEPOSITS

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 MICA SCHISTSLATE

QUARTZITE

GNEISS

Sierra Nevada Mtns

Marble Canyon, Death Valley