Continental Drift & Seafloor Spreading

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  • 1912 – A German scientist by the name of Alfred Wegener made some observations that would set both the worlds of geology and oceanography upside down:
    • Similar plant and animal fossils were found in both Africa and South America and on other continents separated by oceans
    • Similar rock formations were also found on distant continents
    • If you joined Western Europe and Africa together with North and South America, their coastlines would fit together quite nicely
    • He concluded that these formations were once whole and later divided – i.e., the continents were once connected but had separated and drifted apart
    • This concept of a single continent that subsequently broke up is called “Pangaea” – from the Greek, meaning “all lands” 1
  • 1915 – Wegener formulates his “Continental Drift” theory – the central concept is that:
    • The continents float atop the mantle (a heavier, denser layer of rock deep within the earth)
    • The heat rising within the hot mantle created currents of partially melted rocks that move the continents around the earth’s surface 2
  • 1929 – Wegener publishes “The Origin of Continents and Oceans3
  • 1953 – Marie Tharpe discovers the rift valley in sounding profiles made along the Mid-Atlantic Ridge. Later Bruce Heezen and Maurice Ewing determine that there is a continuous oceanic ridge extending over 40,000 nautical miles along all the oceans of the world.
    • This discovery serves as a form of confirmation for Wegener’s Continental Drift ideas 4
  • 1955 – The U.S. Navy engages in a joint project with the Scripps Institution of Oceanography and finds definitive proof that the seafloor is spreading
    • The Coast and Geodetic Survey Ship Pioneer tows the first marine magnetometer and discovers magnetic striping on the sea floor off the west coast of the United States
    • Evidence of a spreading sea floor adds significant credibility to the idea of Pangaea and the concept of Continental Drift 5

“Then God said, “Let the waters under the heavens be gathered together into one place, and let the dry land appear”; and it was so. And God called the dry land Earth, and the gathering together of the waters He called Seas. And God saw that it was good.”

– Genesis 1: 9 – 10

“To Eber were born two sons: the name of one was Peleg, for in his days the earth was divided; and his brother’s name was Joktan.”

– Genesis 10: 25

1. Genesis 1: 9 conveys the idea that when God created the world, initially all of the Land was in one location and the seas were gathered together in another

  • It is interesting that the concept of Pangaea is arguing that such was the case – the land masses of the world (the continents) seem to have been joined

2. By the time Genesis 10 comes around, the Global Flood of Noah’s day has taken place

3. The Scripture then says that in the time of Peleg, the land of the earth began to divide

  • Sure enough, the evidence we have seen from Plate Tectonics and Seafloor Spreading sow this exactly to be the case
  • Science only confirmed this as recently as the latter part of the last century

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  • 1965 – Canadian geophysicist, J. Tuzo Wilson, combines the ideas of “Continental Drift” and “Seafloor Spreading” and proposes the theory of “Plate Tectonics”
    • The concept behind Plate Tectonics is that the Earth’s crust is divided into large ridged pieces called plates
    • The plates float as it were atop an underlying rock layer called the “asthenosphere”
    • Within the asthenosphere, the rocks are under such tremendous heat and pressure that they behave like a viscous liquid

1. The term “continental drift” was no longer fully accurate, because the plates are made up of continental and oceanic crust, which both “drift” over the face of the Earth

  • There are three types of boundaries between the plates:
    • Mid-ocean ridges (where ocean crust is created
    • Trenches (where the ocean plates are subducted)
    • Transform Faults (large fractures in the seafloor where the plates slip by each other

2. Plate Tectonics provided a unifying theory that brings together the moving continents and a spreading seafloor 6