Re: hypothetical question about Noah's flood

Glenn Morton wrote:

"Now, you might say that it is possible to have a global flood which left no evidence of itself. That simply isn't true. There would be some evidence, either in the beaches cut into the soft rock, which can be found at many levels in the mountains and these beaches would be the same elevation around the world. Or the evidence would be in sediment from rapidly moving water. "

I agree there'd be evidence, but would the evidence point convincingly to a global flood? We're talking about a flood that covers the highest mountain tops and then completely recedes in less than a year. Hence the water level would be more or less continuously either rising or falling and therefore would not create well-defined beaches. The water that might be rapidly flowing at one time or another would cause erosion/deposition pretty much indistinguishable from erosion/deposition from other events, would it not? Or else it would leave deposits that simply could not be explained in any reasonable way other than from---your global flood! But we already have lots of deposits that we really don't have good explanations for, and they clearly are not all from the global flood.

Now, if we could find remains of modern organisms at all elevations, such might be good evidence. But they'd likely not have survived the intervening 5000 or so years.

Don

  ----- Original Message -----
  From: glennmorton@entouch.net<mailto:glennmorton@entouch.net>
  To: asa@calvin.edu<mailto:asa@calvin.edu>
  Sent: Saturday, July 23, 2005 6:41 AM
  Subject: Re: hypothetical question about Noah's flood

>How much erosion/sedimenta tion would have occcurred during the flood? What type of sediment load >would we expect to be deposited? Would there even be enough sediment deposited to notice?

  I will only take on this aspect. In order for there to be sedimentation during the flood, one must first have erosion. Erosion is controlled by several factors.

  1.The hardness of the rocks. Very hard rocks, like those found in the Scottish Highlands, erode so slowly that millennia of water pouring over the lip of a cliff will erode only a very small divot into the rock. But soft rocks like many of the shales will erode very fast.

  2. the velocity of the water. slow moving water doesn't erode very much. So a global flood with a gently rising water would do little erosion and have little volumes of sediment to be deposited. Rapidly moving water can move giant boulders

  2a. The velocity of the water is controlled by the slope of the land along which the water flows. Steep gradients means fast water, gentle gradients means slow water.

  2b. The 'head' of the water. If you have several hundred feet of water on a slope, the pressure of the water above the point you are standing at will add to the speed of the water.

  3. the length of time the water reaches a particular level and stays there. A newly formed reservoir can erode beaches in soft sediment within a year.

  Now, you might say that it is possible to have a global flood which left no evidence of itself. That simply isn't true. There would be some evidence, either in the beaches cut into the soft rock, which can be found at many levels in the mountains and these beaches would be the same elevation around the world. Or the evidence would be in sediment from rapidly moving water. And such evidence would last for a very long time. there was a flood in the Altai Mountains of Siberia around 18,000 years ago, yet the evidence is still there.

  "Pleistocene glacial outburst floods were released from ice-
  dammed lakes of the Altay Mountains, south-central Siberia.
   The Kuray-Chuja lake system yielded peak floods in excess
  of 1 x 10^6 m3 s-1 and as great as 18 x 10^6 m3 s-1. The
  phenomenally high bed shear stresses and stream powers
  generated in these flows produced a main-channel, coarse-
  grained facies of coarse gravel in (1) foreset-bedded bars
  as much as 200 m high and several kilometers long, and (2)
  degradational, boulder-capped river terraces. Giant current
  ripples, 50 to 150 m in spacing, composed of pebble and
  cobble gravel, are locally abundant. The whole sedimentary
  assemblage is very similar to that of the Channeled
  Scabland, produced by the Pleistocene Missoula Floods of
  western North America." ~ A. N. Rudoy and V. R. Baker,
  "Sedimentary Effects of Cataclysmic Later Pleistocene
  Glacial Outburst Flooding, Altay Mountains, Siberia,"
  Sedimentary Geology, 85(1993:53-62, p. 53

  And there was a more recent flooding event in the Missoula of Washington State, and it too left evidence. YOu simply couldn't have a global flood which left no evidence. Even such a small flood as that in the Altai left evidence.
Received on Sun Jul 24 01:39:29 2005