British Columbia Geology: Lecture and Video Documentary re Western Canada History Basics

Long ago British Columbia was connected
to Antarctica and Australia. When they split North America meandered North. Our coast
mirrored the Asian coast – islands and shallow seas. Continents move at the
speed a fingernail grows. Molten liquid surrounds a solid spinning metal core that
creates a magnetic field protecting life from the Sun. This heat propels the
continent and ocean plates across the earth. Land gathered into a
supercontinent called Pangaea. Then the Atlantic Ocean opened. North America
split from Europe and Africa moving west. Two island chains and their shallow ocean
floors moved north, merged and collided with the coast causing the deformed
Omenica Belt. More island groups combined for a second collision. Sedimentary rocks split and folded. The weight of the new mountains caused land
to flex leaving a shallow sea. Buried masses of plants would become our oil
and gas. Rock and water slid under the continent. Melting crust created a
volcanic arc and raised the Coast Mountains one of the largest granite
forms stretching from North Vancouver to the Yukon. Recent smaller collisions
created folds that are the Gulf Islands. When pressure released the crust
stretched and thinned. A massive upwelling of flowing lava left flat interior
plateaus. The Coast Mountains completely eroded
but renewed pressure and heat lifted them once again. Even today our North
Shore mountains rise slightly every year. GPS measurements show North America is
turning counterclockwise. The Pacific Plate is moving north. An ongoing
collision is causing BC-Alaska Mountains to rise five centimeters per year. Our entire provincial landscape is shaped by glaciers, slow-moving rivers of
ice that act like large bulldozers. They rounded off mountain peaks, converted
V-shaped valleys into U-shaped. With lower sea levels carved out the long
fjords on our coast. Just sixteen thousand years ago glaciers towered two
kilometers over British Columbia. One lobe enlarged the Georgia Strait and
Puget Sound. In the Okanagan and Thompson Valleys, melting blocks of ice left great
silt cliff benches of sediment that now support our wine and fruit industries. The Fraser River originally flowed north but changed directions to the Pacific. The rugged transition area is not yet eroded thus not navigable. The increased
sediment from the river laid down the land that makes Metro Vancouver. In time
British Columbia will collide with Asia and a new supercontinent may form.

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