H3 Flashcards
age of east african valley
5,3 mil yrs old
age of red sea
25-30 mil yrs old
age of atlantic ocean
50 mil yrs old
age of stille oceaan (pacific)
55 mil yrs old
age of the mediterranean sea
180 mil yrs old
age of the himalayas
225 mil yrs old
alfred wegener
german meteorologist who developed the hypothesis of Continental Drift (verschuiving) in 1915.
Continental Drift hypothesis
“once (>200 million years ago), there was one large landmass (pangea) that slowly fragmented into our current landmassa’s”
how did pangea drift apart?
- the granite continental crust “plowed” through the basalt ocean substrate according to Wegener
- new basalt flowed into the opening and formed the atlantic ocean
is wegener’s hypothesis on how pangea fell apart possible?
he supported his hypothesis with facts, but indirect proof is difficult to measure. There is still no explanation for driving force yet. Despite Wegener’s evidence, it took until about 1950 before the theory was accepted and extended
the moving ocean floor: mid-ocean ridges
here you can find seafloor spreading
seafloor spreading
plates in the lithosphere move away from each other and between the plates, new lithosphere is formed.
what do the structures of mid-ocean ridges show?
- there is tension
- along the axis there are fractures (breuken –> normal faults)
- laterally there are disturbances (verstoringen –> transform faults)
normal fault
a normal fault, also called shear (afschuiving), is vertical and is caused by stress in the opposite direction. This happens with divergent motion.
reverse fault
a reverse fault, also called a shift (opschuiving), is vertical and is caused by compression. This happens with convergent motion.