From: Don Winterstein (dfwinterstein@msn.com)
Date: Sat Apr 19 2003 - 08:19:21 EDT
I'm not terribly knowledgeable about plate tectonics, but since no one else has responded, I'll make a few comments that you might want to check out or include.
>When scientists began bouncing radio waves off the moon they discovered something ..
Did the moon measurements precede those on land? There are direct measurements of relative plate motion going on currently in California and other places. Unfortunately I don't recall the method. Maybe laser interferometry. Also, I'm fairly sure plate tectonics theory took root independently of any moon measurements. To suggest otherwise might be misleading. Press & Siever say the theory received its modern impetus from discovery of the mid-Atlantic ridge and associated phenomena.
>.molten rock boils up in the center..
".hot, viscous rock wells up.."
>The mid Atlantic rift is not quite a straight line ..
Nothing like a straight line. Maybe: "The mid-Atlantic ridge extends the combined north-south dimensions of Europe and Africa and roughly follows the outline of those continents' western edge."
>Relative ages of the rock, measured by radiometric dating techniques, increase going both east and west from the rift center.
David Campbell says most such dates come from fossils at the sedimentary-igneous interface. The fossils have been dated from measurements on land, including radiometric dating of lava flows. Of course, this argument would be lost on YECs. I've never seen an indication that they recognize that fossils can be used for dating. If they did, they wouldn't contend that a single flood can deposit sediments several miles thick (with well-defined variations in fossils following a well-defined pattern throughout).
>The age of the rock is the same at points that are equidistant from the middle of the Atlantic ocean, and increasingly older moving away from the rift.
"Equidistant" is only approximate, and distances should be measured from the ridge, not the middle of the ocean. The really impressive observation is the symmetric pattern of magnetic polarity reversals, where the axis of symmetry is the ridge axis.
>For example, the relative amount of decay isotopes present in rock 1,000 miles east of the rift will be the same as that contained in rock 1,000 miles to the west.
Again, the distances are not that precise--as would be expected from a relatively messy process of magmatic extrusion combined with the transform faulting. Would be best to couch the dates in terms of their relationships to the symmetric magnetic striations.
(Actually, the fact that the distances are _roughly_ equal suggests to me that the driving force may well have more to do with pressure from upwelling magma than from mantle convection or pull-down from subduction zones. [Don't include this!])
>In addition, the iron contained in the deposits when the molten rock first reaches the ocean floor and solidifies, orients itself with the same polarity as the earth.
"Magnetizable minerals" would be better than "iron." Also, ".align themselves with Earth's magnetic field."
>Again, at equidistant points we see regular reversals in polarity many times in the last 200 million years since the continents were joined.
To either side of the ridge we see a symmetric pattern of polarity reversals. These reversals took place at intervals ranging from a few thousand to 200,000 years.
>.we see pole swapping clearly occurring in sine wave fashion.
Clearly occurring at irregular intervals.
Note: Help from Frank Press & Raymond Siever, Earth.
----- Original Message -----
From: Dick Fischer
To: ASA
Sent: Friday, April 18, 2003 10:38 AM
Subject: Plate Tectonics
Here is an anti-YEC argument from nature. (I borrowed a little from Don Winterstein.) Can anybody see necessary additions or corrections?
Plate Tectonics
When scientists began bouncing radio waves off the moon they discovered something which to them at the time appeared quite odd. Instead of being stationary, the major continents were drifting ever so slightly but perceptively such that the continents were moving apart. This detected movement is one independent measure of what has become a staple of geologic theory - plate tectonics.
The mid Atlantic rift lies midway between the continents of North and South America to the west and Europe and Africa to the east. As the continents drift slowly in opposite directions, molten rock boils up in the center and solidifies when it hits the cold water on the sea floor. The mid Atlantic rift is not quite a straight line that stretches north and south.
At present, we don't know whether the molten rock boiling up from the earth's mantle exerts a force pushing the continents away from each other, or whether the momentum of the moving continents drawing apart causes a fissure which the molten rock fills, or whether there is a combination of forces at work.
Samples of the rock have been taken from the sea floor. Relative ages of the rock, measured by radiometric dating techniques, increase going both east and west from the rift center. The age of the rock is the same at points that are equidistant from the middle of the Atlantic ocean, and increasingly older moving away from the rift.
For example, the relative amount of decay isotopes present in rock 1,000 miles east of the rift will be the same as that contained in rock 1,000 miles to the west. An equal amount of decay elements are found at all points that are equidistant from each other going east and west.
In addition, the iron contained in the deposits when the molten rock first reaches the ocean floor and solidifies, orients itself with the same polarity as the earth. Again, at equidistant points we see regular reversals in polarity many times in the last 200 million years since the continents were joined.
Whether the Genesis flood was local or global can be argued, but let's assume that the flood occurred about 5,000 years ago. Since that point in time, there have been no magnetic pole reversals. So we can say that no reversals have occurred in the last 5,000 years.
Yet from core samples taken from the ocean floor, and from many other samples taken from all over the earth, we see pole swapping clearly occurring in sine wave fashion. And from recent data we can detect a slight decline in magnetic strength as the earth moves slowly toward another reversal.
Working the data back, we can see that the continents were joined at one time. This massive formation of all the continents joined together roughly 200,000 million years ago has been dubbed "Pangea." Since that time the continents have been drifting apart.
Antarctica, which now covers the South Pole, once was located in temperate climates. Dinosaur bones have been found there, yet remains of more recent mammalian, land animals are absent. This is consistent with our knowledge of the periods of earth history when dinosaurs roamed the earth from 225 million years ago to 65 million years ago, and mammals only came into existence during the last 150 million years
Plate tectonics data constitutes one of the best data sets an informed Christian might use to convince an open-minded young-earth creationist that the world is not as young as he or she might think. Have young-earth creationists provided an explanation as to how the mechanics of plate tectonics could be explained in the span of one year at the time of the flood? No.
Only an earth that has been around for a long time (at least hundreds of millions of years) could leave this kind of consistent data testifying to its ancient geologic history.
Dick Fischer - Genesis Proclaimed Association
Finding Harmony in Bible, Science, and History
www.genesisproclaimed.org
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