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Author Topic:   Mid-ocean Ridges and Age of Formation
RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 1 of 2 (713880)
12-17-2013 12:30 PM


I may not be the best source to initiate this, as my knowledge of geology is weak.
That said I come to this topic as a side issue from Geology and the Great Flood, Why the Flood Never Happened, Message 290 where Faith is asking questions about Tectonics.
It occurs to me that a basic discussion of the mid-ocean ridges would help in
  1. showing the basic source of tectonic plate movement in a clear and unambiguous way, and
  2. showing how the age of the sides increase as you move away from the ridge, thus
  3. showing the basic rate of movement of the plate on each side and
  4. how constant that rate is
  5. that this process is going on today
  6. the time it takes for this to happen
It occurs to me that these ridge patterns are like tree rings and varves ...
Mid-ocean ridge - Wikipedia
The mechanism behind Plate Tectonics
quote:
Plate Tectonics: The Mechanism
The main features of plate tectonics are:
  • The Earth's surface is covered by a series of crustal plates.
  • The ocean floors are continually moving, spreading from the center, sinking at the edges, and being regenerated.
  • Convection currents beneath the plates move the crustal plates in different directions.
  • The source of heat driving the convection currents is radioactivity deep in the Earths mantle.
Mid-Oceanic Ridges
The mid-oceanic ridges rise 3000 meters from the ocean floor and are more than 2000 kilometers wide surpassing the Himalayas in size. The mapping of the seafloor also revealed that these huge underwater mountain ranges have a deep trench which bisects the length of the ridges and in places is more than 2000 meters deep. Research into the heat flow from the ocean floor during the early 1960s revealed that the greatest heat flow was centered at the crests of these mid-oceanic ridges. Seismic studies show that the mid-oceanic ridges experience an elevated number of earthquakes. All these observations indicate intense geological activity at the mid-oceanic ridges.
Geomagnetic Anomalies
Occasionally, at random intervals, the Earth's magnetic field reverses. New rock formed from magma records the orientation of Earth's magnetic field at the time the magma cools. Study of the sea floor with magnometers revealed "stripes" of alternating magnetization parallel to the mid-oceanic ridges. This is evidence for continuous formation of new rock at the ridges. As more rock forms, older rock is pushed farther away from the ridge, producing symmetrical stripes to either side of the ridge. In the diagram to the right, the dark stripes represent ocean floor generated during "reversed" polar orientation and the lighter stripes represent the polar orientation we have today. Notice that the patterns on either side of the line representing the mid-oceanic ridge are mirror images of one another. The shaded stripes also represent older and older rock as they move away from the mid-oceanic ridge. Geologists have determined that rocks found in different parts of the planet with similar ages have the same magnetic characteristics.
Presumably the ridges are date-able by radiometric means, and there should be a number of different techniques to use so they can be checked for consilient dates.
Enjoy
Edited by RAZD, : image added

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AdminNosy
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Message 2 of 2 (713890)
12-17-2013 1:37 PM


Thread Copied to Geology and the Great Flood Forum
Thread copied to the Mid-ocean Ridges and Age of Formation thread in the Geology and the Great Flood forum, this copy of the thread has been closed.

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