GEOLOGY EXAM 2

IGNEOUS

Rocks made from magma

OBSIDEAN

black , glassy, shiny, sharp

SCORIA

vesicular ( holes ) , dark

PUMICE

holes , light in color, use it in my shower

BASALT

dark. kind of angular, heavy , black , feels like a rock

GRANITE

pink(typically ) , black , white, crystal -ish,

DIORITE

black and white (equal amounts )

GABBRO

dark, opposite of diorite, more dark with specks of white

PEGMATITE

large crystals , colorful

SEDIMENTARY

made from other rocks ( weathering )

BRECCIA

multiple angular grains

CONGLOMERATE

multiple round grains

QUARTZ SANDSTONE

feels sandy and can often see layers

ARKOSE

pink tint , grainy/ gravely

OOLITIC LIMESTONE

OOIDS ( made up of ) , chemical , composed if calcite ( fizzes )

COQUINA

composed of a collection of shells , also fizzes

FOSSILIPHEROUS LIMESTONE

broken down shells and it also fizzes

MICRITE

very smooth and light in color ( yellow)/ also fizzes

CHALK

made from coccolithophores, crumples

PEAT

dirt

bituminous coal

plastic feeling / looking, light in weight and shiny

METAMORPHIC

Rocks that are transformed into other rocks through a long process that can involve pressure, heat, differential stress and sometimes water

QUARTZITE

looks like dense milky quartz ( can be pink or white ) ( does not fizz ) (MOTHER( PROTOLITH ) IS SANDSTONE )

MARBLE

pink or white , reacts with acids looks like quartzite ( MOTHER OF LIMESTONE ( PROTOLITH )

SLATE

smooth , our sample is red but isn’t always that color, layers

PHYLITE

looks like slate but its shiny with layers

SCHIST

very shiny with mica

GNEISS

looks like zebra

FOSSILS

can be found in rocks , remains of once living organisms

GASTROPODS

snail like with spirals

BIVALVES

like todays clams and oysters

BRACHIOPODS

fat , symmetrical, look like a nut, extinct

TRILOBITES

look like horseshoe crab skeleton

CORAL

in the seas ( horn coral, wide coral )

BACULITES / CEPHLOPODS

pointy octopus cone looking with pattern

SHALE IS THE PROTOLITH OF

slate

phyllite

schist

gneiss

PEGMATITIC

very large crystal grains/ slow cooling / addition of hot water ( ONLY PEGMATITE )

PHANERITIC

(coarse grained slow cooling ) ex is granite

APHANITIC

fine grained/ fast cooling ( ex is basalt)

VESICULAR

holes , rapid cooling , made from frothy magma that has risen to the top( ex is pumice )

GLASSY

glassy, magma cools so fast crystals can’t form( ex is obsidian )

PORPHYRITIC

phenocryst ( small pieces ) ground mass ( big pieces ) starts underground and then mores higher up

INTERMEDIATE

equal amounts of magic and felsic crystals ( phaneritic side )

dim dusty grey which is on the aphanitic side