Sample Critical Thinking On Plate Tectonics

The plate tectonics is a theory on the origin and the movement of the current continents that was proposed by Alfred Wegener. There are seven major continents such as North and South America, Africa, Europe, Asia, Australia, and Antarctica. According Wegener, the current continents were once connected in one big super continent called Pangaea (in Greek means “all land”). Wegener claimed that the convectional currents in the interior of Pangaea caused it to break into two; Eurasia to the north and Gondwanaland to the south separated by Tethys Sea. The convectional currents caused further breakup of Eurasia and Gondwanaland to form the current continents (plates). The plates are in a constant movement called continental drifting. Continental drift causes the plates to move away from each other, towards each other, or past each other. The movement occurs due to the conventional current in the asthenosphere, a molten layer on which all the continents floats (David Pratt, 2000).
There are various concepts and ideas that Wegener used to support his idea on plate tectonics. First, he opined that when the current continents are brought together, they tend to fit into one continent. For examples, taking the East South American continent margin and bring it to the West African continent margin, they would fit. In addition, fossils (for both plants and animals) found in South American continent are similar to those found on the western coast of the African continent. The same case applies to fossils found in Antarctica and Australia. With the vast mass of sea separating these continents, it is only if they were once joined that the same animal species roamed freely on them.
There are evidences that the plates move. First, see floor has been spreading as new rocks from the interior of the earth come up to replace the gap left when the continents move apart in the extension boundary. The presence of new rocks is also evidence that there is line of weakness upon which the continents move. The convergence bounders have been folding like the North African margin and the European margin are converging leading to formation of Fold Mountains –Atlas Mountains.
Understanding plate tectonics is beneficial to human since the movement causes instability in some regions such as in areas of converges where Fold Mountains are found as well as causes volcanic eruptions on the extension boundaries. Understanding these facts can help humans in planning for land use.

Works cited

“Plate Tectonics.” Accessed on March 3, 2015 from http://www.tclauset.org/20_ESbk/ch08.pdf
David Pratt. Plate Tectonics: A Paradigm Under Threat. PDF. Journal of scientific exploration. Vol. 14, No. 3, pp. 307-352. 2000. Accessed on March 3, 2015 from http://www.scientificexploration.org/journal/jse_14_3_pratt.pdf