THE INTERNAL STRUCTURE: OCEAN BASIN Flashcards
geologic process in which tectonic plates split apart from each other as a result of mantle convection.
SEAFLOOR SPREADING
CONTINENTAL DRIFT EVIDENCE
The Jigsaw fit of Africa and South America
Fossils
Glaciers
Mountains and mineral deposits
Coal belts
South America and Africa fit; Europe and north America fits together
Jigsaw fit of Africa and South America
Glacial scarring of rock.
Scour
the oldest continental rocks dated by radioactivity
3.98 billion years old
Wegener first presented his idea of continental drift in ____
1912
the top layer of earth’s crust is broken up into large slabs
plates
the movement of lower molten layers causes the plates to shift.
plate tectonics
scientists estimate that the continents move anywhere from:
one centimeter to several inches per year
studying the magnetism of rocks from varying geological period revealed the orientation of the Earth’s magnetic field at the time of the rock’s formation.
PALEOMAGNETISM
Wegener’s continental drift theory finally became generally accepted in the 1950’s and 1960’s through evidence provided by the study of :
PALEOMAGNETISM
This suggest that the continents and ocean are probably permanent features of Earth’s surface
PLATE BOUNDARIES
two tectonic plates move away from each other.
Divergent Boundary
two tectonic plates come together.
Convergent Boundary
splits into two pieces and carried in opposite directions.
Transform plate boundary:
7 major tectonic plate
`African Plate
Antarctic Plate
Eurasian Plate
Indian-Australian Plate
North America Plate
Pacific Plate
South America Plate
7 minor tectonic plate
Arabian Plate
Caribbean Plate
Cocos Plate
Juan de Fuca Plate
Nazca Plate
Philippine Plate
Scotia Plate
are areas found under the sea.
ocean basins
These areas can be relatively inactive areas where deposits of sediment slowly collect, or active areas where tectonic plates meet.
ocean basins
The ocean floor is primarily composed of:
basalt and gabbro.
It is normally found rising above the ocean floor at the center of the ocean basins.
Mid-oceanic ridge
Mid-oceanic ridge constitutes __% of the Earth’ surface
23%
They are long narrow, steep-sided depressions that contain the greatest depths in the ocean.
Ocean Trenches
another raised feature found within ocean basins and found on the deep ocean floor.
Abyssal Hill/Plain
These features can be very large submerged volcanic mountain reaching heights up to 10,000 feet.
Seamounts
it is similar to a seamount, but it is submerged volcanic mountain with a flat top. It’s structure is due to erosive processes caused by waves after years
Guyot
This feature found gently sloping area before the ocean floor and at the base of the continental slope and formed by emerging accumulates deposits at the mounts of many submarine canyons.
Continental Rise
is a shallow, gently sloping part of the continent crust
Continental Shelf
This part of the ocean basin extends and slopes after the continental shelf
Continental Slope
The boundary between the continental slope and shelf is called ______________
continental shelf break
are composed of layers or features called strata
ROCKS
These layers are used to determine the age of rocks.
rock strata
Almost the same as sedimentary rocks.
Stratified Rocks
Stratification, is also called
bedding
is the study of rock layers and their relationships to each other
Stratigraphy
TELL US THE SEQUENCE IN WHICH EVENTS OCCURED, NOT HOW LONG AGO THEY OCCURED.
CHRONOLOGICAL ORDER
RELATIVE
PROCESS OF ESTABLISHING THE AGE OF AN OBJECT BY DETERMINING THE NUMBER OF YEARS IT HAS EXISTED.
ABSOLUTE