Transcript extrusive volcanism

It may be that your sole purpose in life is
simply to serve as a warning to others.
- Unknown –
After one look at this planet any visitor from
outer space would say "I WANT TO SEE THE
MANAGER."
- William S. Burroughs-
“THE RUINS OF AN OLDER WORLD ARE VISIBLE IN
THE PRESENT STRUCTURE OF OUR PLANET. THE
STRATA WHICH NOW COMPOSE OUR CONTINENTS
WERE ONCE BURRIED BENEATH THE SEA AND WERE
FORMED OUT OF PRE-EXISTING CONTINENTS.”
- FROM “READING THE ROCKS” -
THE ROCK CYCLE
LET’S FOCUS ON WHERE IGNEOUS ROCKS
ARE FORMED.
-NEW CRUST
-CRUST BECOMING WIDER
-SHALLOW EARTHQUAKES
-EXTRUSIVE VOLCANISM
-MID OCEAN RIDGES
CONVERGENT PLATE BOUNDARY INVOLVING
OCEANIC CRUST
- EARTHQUAKES
- EXTRUSIVE VOLCANISM
- INTRUSIVE VOLCANISM
- MOUNTAIN BUILDING
HOT SPOT
- EXTRUSIVE VOLCANISM
- INTRUSIVE VOLCANISM
- EARTHQUAKES
HAWAIIAN-EMPEROR SEAMOUNT CHAIN
EXTRUSIVE VOLCANIC ROCKS FORM AT OR
NEAR THE SURFACE.
THEY COOL RELATIVELY QUICKLY AND ARE
FINE-GRAINED OR GLASSY.
EXAMPLES ARE BASALT, SCORIA, PUMICE,
AND OBSIDIAN.
INTRUSIVE VOLCANIC ROCKS FORM
BENEATH THE SURFACE AND COOL
SLOWLY. THEY ARE MORE COARSE
GRAINED.
AN EXAMPLE IS GRANITE.
METAMORPHISM – RECRYSTALLIZATION
OF ROCK DUE TO HIGH TEMPERATURES
AND PRESSURES TO FORM NEW MINERALS
METAMORPHIC CHANGES CAN OCCUR
WITH IGNEOUS ROCK OR SEDIMENTARY
ROCK
LIMESTONE CAN CHANGE INTO MARBLE.
SHALE CAN CHANGE INTO SLATE.
BASALT CAN CHANGE INTO BLUESCHIST.
ROCKS THAT CONTAIN SAND AND CLAY
CAN CHANGE INTO SCHIST OR GNEISS.
SEDIMENTARY ROCKS ARE FORMED AS A
RESULT OF TRANSPORTATION AND
DEPOSITION OF ROCK PARTICLES
(EROSION).
OVER TIME, THESE PARTICLES UNDERGO
COMPACTION AND CEMENTATION.
ROCK EVENTUALLY GETS UPLIFTED IN
THE MOUNTAIN BUILDING PROCESS.
MOUNTAIN BUILDING OCCURS ALONG
CONVERGENT PLATE BOUNDARIES.
IF THE CONVERGENT PLATE BOUNDARY IS
OCEAN-OCEAN OR OCEAN-CONTINENT,
MUCH OF THE MOUNTAIN BUILDING IS
VOLCANIC IN NATURE.
IF THE BOUNDARY IS CONTINENTCONTINENT, THE MOUNTAIN BUILDING
IS BY UPLIFT.
THE PROCESS OF ONE PLATE MOVING
UNDER ANOTHER IS CALLED
SUBDUCTION.
ONCE MATERIAL HAS BEEN UPLIFTED, IT IS
SUBJECT TO WEATHERING AN EROSION.
WEATHERING
NOTE: ROCKS DON’T LAST FOREVER!!
PUTTING IT ALL TOGETHER