MARINE GEOLOGY & GEOGRAPHY

MARINE GEOLOGY

Marine Geology

4 LAYERS OF THE EARTH

Layers of the Earth

4 LAYERS OF THE EARTH

Layers of the Earth

CRUST

• THICKNESS: VARIES BETWEEN OCEAN & CONTINENTS 5-40 KM

• STATE: SOLID

• ELEMENTS: SILICON, ALUMINUM, CALCIUM, SODIUM, POTASSIUM

• LOCATION OF THE EARTH’S “PLATES”

• FLOATS ON THE LAYER BENEATH

• LEAST DENSE LAYER

• CONTINENTAL AND OCEANIC CRUSTS

• LITHOSPHERE= CRUSTS + UPPER MOST PART OF MANTLE

Layers of the Earth

MANTLE

• THICKNESS: 2,750 KM

• STATE: PLASTIC- ABILITY OF A SOLID TO FLOW

• ELEMENTS: SILICON, OXYGEN, MAGNESIUM, IRON, ALUMINUM, CALCIUM

• CONVECTION CURRENTS

• DUE TO UNEVEN HEATING IN THIS LAYER

• CAUSE THE EARTH’S PLATES TO MOVE

• ASTHENOSPHERE AND MESOSPHERE

Layers of the Earth

OUTER CORE

• THICKNESS: 2,260 KM

• STATE: LIQUID

• ELEMENTS: IRON AND NICKEL

• EXTREMELY HOT

• RESPONSIBLE FOR OUR MAGNETIC FIELD

Layers of the Earth

INNER CORE

• THICKNESS: 1,228 KM

• STATE: SOLID

• TEMPERATURE AND PRESSURE IS SO GREAT, THAT THE METALS ARE

SQUEEZED TOGETHER AND CANNOT MOVE.

• ELEMENTS: IRON AND NICKEL

Layers of the Earth

PLATE TECTONICS

• ALFRED WEGENER

• KNOWN FOR HIS THEORY ON

CONTINENTAL DRIFT

• 1915- PUBLISHED THE ORIGINS OF

CONTINENTS AND OCEANS

• CONTINENTAL DRIFT

• SUPERCONTINENT- PANGEA

Plate Tectonics

PLATE TECTONICS

• CONTINENTAL DRIFT SUPPORTED BY:

• IDENTICAL FOSSILS FOUND ON DIFFERENT CONTINENTS

• CONTINENTS “FIT” TOGETHER LIKE PUZZLE PIECES

• GEOLOGICAL FEATURES MATCH TOGETHER

• COAL DEPOSITS IN EUROPE AND N. AMERICA

• MOUNTAIN RANGES IN AFRICA AND S. AMERICA

Plate Tectonics

Plate Tectonics

PLATE TECTONICS

• SO WHAT CAUSED THE PLATES

TO MOVE APART?

• THE CRUST IS MADE UP OF

SEVERAL DIFFERENT PLATES THAT

CAN MOVE INDEPENDENTLY OF

ONE ANOTHER

• CONVECTION CURRENTS IN THE

MANTLE PUSH/PULL THE PLATES

Plate Tectonics

PLATE BOUNDARIES

Plate Tectonics

DIVERGENT BOUNDARIES

• OCEAN- (SEA-FLOOR SPREADING)

• TWO PLATES MOVE AWAY FROM EACH OTHER

• MAGMA MOVES UP TO FILL THE SPACE

CREATING NEW ROCK

• FORMS OCEAN RIDGES

• CONTINENTAL-

• FORMS RIFT VALLEYS

Plate Tectonics

CONVERGENT BOUNDARIES

• PLATES MOVE TOWARDS EACH OTHER

• AKA: SUBDUCTION ZONES- AREAS OF

PLATE DESTRUCTION

• 3 TYPES:

• OCEANIC- OCEANIC

• OCEANIC- CONTINENTAL

• CONTINENTAL- CONTINENTAL

Plate Tectonics

CONVERGENT: OCEANIC- OCEANIC

• FORMS:

• TRENCHES

• ISLAND ARCS

Plate Tectonics

CONVERGENT: OCEANIC- CONTINENTAL

• FORMS:

• TRENCHES

• VOLCANIC ARCS

Plate Tectonics

CONVERGENT: CONTINENTAL- CONTINENTAL

• FORMS:

• MOUNTAINS

Plate Tectonics

TRANSFORM BOUNDARIES

• OCCURS AS TWO PLATES SLIDE

PAST EACH OTHER

• NO PLATE DESTRUCTION

• EARTHQUAKES ARE COMMON

DUE TO FRICTION

• OFFSETS GEOLOGIC FEATURES

Plate Tectonics

PLATE BOUNDARIES

Plate Tectonics

OTHER CIRCUMSTANCES

• SOME AREAS HAVE PLUMES OF

MAGMA CLOSE TO THE SURFACE

• AKA: HOT-SPOTS

• RESPONSIBLE FOR SEVERAL ISLAND

CHAINS INCLUDING HAWAII

• MAGMA RISES TO THE SURFACE AT

VOLCANOES CREATING NEW

ISLANDS

Plate Tectonics

OTHER CIRCUMSTANCES

• HYDROTHERMAL VENTS

• SEA WATER SEEPS THROUGH

CRACKS IN THE CRUST NEAR

PLATE BOUNDARIES

• IT GETS HEATED CLOSE TO

MAGMA CHAMBERS

• RUSHES BACK TO THE CRUST

CARRYING NUTRIENTS

Plate Tectonics