Essay about Continetal drift theory

In 1596- Abraham Ortelius took note that the coastlines of the continents seemed to be too fitting together. He initiated a theory that stated that the continents were probably joined at one point in time and were torn apart between Europe and Africa. In the year of 1912, Alfred Wegener stated that the continents were once joined in a supercontinent called Pangea.

One evidence of this theory is molten material. Molten Material is magma erupting from mid-ocean ridges. Alvin the submarine found weird rocks shaped like pillows or toothpaste. This tells us this magma cools quickly underwater. Another type of evidence are magnetic stripes. Magnetic stripes are patterns in the ocean floor to prove Earth’s magnetic field has reversed itself in history. Scientist also looked at the “magnetic memory” of the rocks. Scientist drilled pipes through water to drill holes into the ocean floor. Scientists discovered that the older rocks were further away and younger rocks were closer. Those were the three types of evidence that scientist used to support the theory of Sea Floor Spreading.

Although there are other volcanic events that don’t prove that the tectonic theory is valid. For example The "Ring of Fire" is an arc stretching from New Zealand, along the eastern edge of Asia, north across the Aleutian Islands of Alaska, and south along the coast of North and South America. The Ring of Fire is composed over 75% of the world's active and dormant volcanoes. This huge ring of volcanic and seismic (earthquake) activity was noticed and described before the invention of the theory of plate tectonics theory. Also without movement at the boundaries around the Pacific, volcanoes such as Mt St Helens would simply not exist, as they would have no fuel caused by the subduction of an oceanic plate under a continental plate.

Volcanic and Seismic events are major pieces of evidence towards proving that plate tectonics theory is valid (40 marks)

In junior high school, I have learned the Continental Drift Theory, and my geography teacher told me there was a new theory based on the Continental Theory, i.e. Plate Tectonics. I accessed to the Internet to find the information about Plate Tectonics.

Between 280 million and 225 million years ago, the earth’s previously separated land areas became welded into a landmass called Pangaea. About 120 million years ago, due to the continental drift, this landmass began to separate. It split the old world and the new world apart, which dividing North and South America from Eurasia and Africa. The separation lasted for million years that it fostered divergent evolution. The new world and the old world’s biological evolution followed individual paths, becoming two separate biological worlds. However, after 1492, human voyagers reversed this tendency. In October 1492, Christopher Columbus and his crew landed in Bahamas. After Columbus arrived in

Studies of the age of molten rock in the ocean crust confirm the magnetic data. Molten rock contains radioactive isotopes used to calculate the time of the eruption. Rocks near the Mid- Atlantic Ridge, in addition to current like structures happened to be rather young, only some million years aged or a lesser amount (Trefil & Hazen, 2010). Rocks gathered one after another farthest from the range established them to be in turn older. Up to date evidence on charting the surfaces of oceans, maps of rock magnetism, and data on the age of rock indicate to countless expert that the span of the Atlantic Ocean for all intents and purposes is

James Hutton was the first scientist to address the Earth was millions of years old, as well as alive and is continuously being formed. Charles Lyell popularized uniformitarianism, and believed the Earth was being shaped by slow moving forces. Alfred Wegener introduced the foundation for the theory of continental drift. Wegener was one of the first to recognize and have an understanding of how the Earth works which required data and information from earth sciences. In the 1960s, the theory for the continental drift became known as the theory of plate tectonics or plate building.

About 200 million years ago there was one big continent called Pangaea. They believed that, this landmass began to separate. They believed that the Atlantic Ocean formed, dividing Africa and Eurasia from the Americas. Over the next several million years plants and animals changed and made to separate biological worlds. It wasn’t until Christopher Columbus and his crew sailed to the Americas in October 1492, they started interacting with each other.

If new crust is indeed being produced at the rifts, where does the additional older crust go?

The theory of Pangaea suggests that the continents were once stuck together into one huge continent. Eventually they started drifting into separated landmasses, which gave birth to the modern continents.

2. What was the first line of evidence that led early investigators to suspect that the continents were once connected?

Plate tectonics is the scientific theory that attempts to explain the movements of the Earth's lithosphere that have formed the landscape features we see across the globe today” (Briney). Geology defines “plate” as a large slab of solid rock, and “tectonics” is part of the Greek root word for “to build.” Together the words define how the Earth’s surface is built up of moving plates. The theory of plate tectonics dictates that individual plates, broken down into large and small sections of rock, form Earth’s lithosphere. These fragmented bodies of rock move along each other atop the Earth’s liquid lower mantle to create the plate boundaries that have shaped Earth’s landscape. Plate tectonics originated from meteorologist Alfred Wegener’s theory, developed in the early 20th century. In 1912, he realized that the east coast of South America and the west coast of Africa appeared to piece together like a jigsaw puzzle. He further examined the globe and deduced that all of Earth’s continents could somehow be assembled together and proposed the idea that the continents had once been linked in a single supercontinent called Pangaea. To explain today’s position of the continents, Wegener theorized that they began to drift apart approximately 300 million years ago. This theory

Continental drift was a theory offered by Alfred Wegener in 1912 that hypothesized that all the continents at one time fit together as one land mass. Wegener, explained that the ends of each continent could fit together like a puzzle and that over time the continents drifted apart. "The model explained why the same types of fossils occur in sedimentary rock on both sides of the vast Atlantic Ocean" (Star, 2008, pg. 250), in other words allopatric speciation. Wegener's theory did not have a supporting geological mechanism. Many years later and advances in technology brought about the plate tectonics theory. Essentially it says:

After World War 2, the U.S. Office of Naval Research intensified efforts in ocean-floor mapping, leading to the discovery of the Mid-Atlantic Ridge to be part of a continous system of mid-oceanic ridges on all ocean floors, prompting Harry H. Hess to suggest the theory of sea-floor spreading. The oldest fossils found in ocean sediments were only 180 million years old and little sediment were accumulated on the ocean floor. Thus, he suggested that seafloors were no more than a few hundred million years old, significantly younger than continental land due to