Continental drift Pangaea My drift Commentary

Alfred Lothar Wegener geophysics

Continental drift

• Eduard Suess had lined up the mountains on different continents
• by linking their fossils, but he claimed that land-bridges
• connecting the continents must have sunken below the ocean,
• which Alfred Wegener realized would not work because it contradicted
• the geological buoyancy of the continental masses. Wegener further
• realized that the continents had been slowly drifting about the globe,
• and that the mid-ocean ridges were being filled with new seafloor
• as each side spread apart. Nevertheless, Wegener did not understand
• the cause of continental drift. That waited for the theory of plate tectonics.

Pangaea

• Pangaea, which Wegener called Urkontinent,
• existed from three hundred million years ago
• when all the continents and subcontinents
• were jammed together.
• Two hundred million years ago, Panaea began
• to split into Gondwana to the south
• and Laurasia to the north.
• Gondwana included Antarctica, Africa,
• Madagascar, Australia, Arabia, India,
• and South America
• and began to break up in the early Jurassic,
• about one hundred eighty-four million years ago.
• Laurasia included Europe without the Balkans,
• Siberia, Asia without India, Greenland,
• and North America
• and began to break up at the end of the Paleocene,
• about fifty-five million years ago.
• Today, India is ramming into Asia
• lifting up the Himalayas
• and the Great Rift is separating Africa
• from its horn.

My drift

• If you get my drift,
• my slowly imperceptible
• displacement, then
• you might begin
• to correlate other facts
• in reconstructing my past.
• Not everything has been
• lost, I could say, none
• of the important things,
• but even trivial fossils
• have become important
• enough to cherish.