Editing Continental drift (section)

====Modern evidence====
Geophysicist [[Jack Oliver (scientist)|Jack Oliver]] is credited with providing seismologic evidence supporting plate tectonics which encompassed and superseded continental drift with the article "Seismology and the New Global Tectonics", published in 1968, using data collected from seismologic stations, including those he set up in the South Pacific.<ref name="NYTimes-2011" /><ref name="Isacks-1968" /> The modern theory of [[plate tectonics]], refining Wegener, explains that there are two kinds of crust of different composition: [[continental crust]] and [[oceanic crust]], both floating above a much deeper "[[Plasticity (physics)|plastic]]" mantle. Continental crust is inherently lighter. Oceanic crust is created at [[Seafloor spreading|spreading centers]], and this, along with [[subduction]], drives the system of plates in a chaotic manner, resulting in continuous [[orogeny]] and areas of isostatic imbalance.

[[File:Mesosaurus.png|thumb|''Mesosaurus'' skeleton, MacGregor, 1908]]

[[File:Snider-Pellegrini Wegener fossil map.svg|thumb|upright=1.5|Fossil patterns across continents ([[Gondwanaland]]) ]]

Evidence for the movement of continents on tectonic plates is now extensive. Similar plant and animal [[fossil]]s are found around the shores of different continents, suggesting that they were once joined. The fossils of ''[[Mesosaurus]]'', a freshwater reptile rather like a small crocodile, found both in [[Brazil]] and [[South Africa]], are one example; another is the discovery of fossils of the land [[reptile]] ''[[Lystrosaurus]]'' in [[Rock (geology)|rocks]] of the same age at locations in [[Africa]], [[India]], and [[Antarctica]].<ref name="USGS" /> There is also living evidence, with the same animals being found on two continents. Some [[earthworm]] families (such as Ocnerodrilidae, Acanthodrilidae, Octochaetidae) are found in South America and Africa.

The complementary arrangement of the facing sides of South America and Africa is an obvious and temporary coincidence. In millions of years, [[slab pull]], [[ridge-push]], and other forces of [[tectonophysics]] will further separate and rotate those two continents. It was that temporary feature that inspired Wegener to study what he defined as continental drift although he did not live to see his hypothesis generally accepted.

The widespread distribution of [[Permo-Carboniferous]] glacial sediments in South America, Africa, Madagascar, Arabia, India, Antarctica and Australia was one of the major pieces of evidence for the theory of continental drift. The continuity of glaciers, inferred from oriented [[glacial striation]]s and deposits called [[tillite]]s, suggested the existence of the supercontinent of [[Gondwana]], which became a central element of the concept of continental drift. Striations indicated glacial flow away from the equator and toward the poles, based on continents' current positions and orientations, and supported the idea that the southern continents had previously been in dramatically different locations that were contiguous with one another.<ref name="Wegener-1966" />