Robie Mar V. Macalalad
HUMSS 11 – Geronima Pecson
Geology & Oceanography
“The first concept of continental drift first came to me as far back as 1910, when considering the
map of the world, under the direct impression produced by the congruence of the coast lines on
either side of the Atlantic. At first I did not pay attention to the ideas because I regarded it as
improbable. In the fall of 1911, I came quite accidentally upon a synoptic report in which I
learned for the first time of palaeontological evidence for a former land bridge between Brazil
and Africa.”
- Alfred Wegener, German meteorologist and geophysicist, Continental Drift Theory
Get a map and look at the continent of South America and Africa, what do you noticed?
The edge of the continent looks like it is torn apart or it looks like a puzzle piece that is
separated. It is the plate tectonics. Plate tectonics is the most important lesson or topic in
geology. That idea was hypothesized by a German meteorologist and geophysicist Alfred
Wegener in 1912. According to Wegener, continents pass about on Earth's surface and were once
united as a single supercontinent. He suggested that the continents were once merged into a
single supercontinent known as Pangaea, which in ancient Greek meant "all earth." He proposed
that Pangaea disintegrated long ago and the continents then moved to their new locations. His
theory was named continental drift.
Alfred Wegener’s continental drift theory was no only about the puzzle-like continent
structures but he also provided evidences to support more his claim. First evidence is the
matching sequence of rocks and mountain chains like the Appalachians of the eastern United
States and Canada is just like the mountain ranges in eastern Greenland, Ireland, Great Britain,
and Norway. Second evidence is on both sides of the Atlantic Ocean, identical rocks of the same
form and age can be found. According to Wegener, the rocks built side by side and the land has
since shifted apart. Next is the glaciers, evidence of glaciation in now tropical regions and the
direction of glacial flow and rock scouring. Lastly evidence is extinct plant and animal fossils
from the same species have been discovered in the same age rocks on continents that are now
separated by a great distance. Wegener suggested that the animals had coexisted before dying
and being fossilized, but that the lands had drifted apart since they died. He hypothesized that the
species may not have been able to navigate oceans. But Wegener hypothesis was rejected and
declined by many scientist because of the biggest flaw in his hypothesis was the incapacity to
provide mechanism for how the continents move.
A World War II submarine captain and geologist Harry Hess, he noticed that depth
recordings shows sea floor features. He proposed the idea seafloor spreading and the mantle
convection cells as driving mechanism. The geologic process of seafloor spreading occurs when
tectonic plates—large slabs of Earth's lithosphere—split apart from one another. Mantle
