Re: Coral reef growth

From: Keith Miller (
Date: Sun Dec 01 2002 - 21:16:01 EST

  • Next message: Robert Schneider: "The James Ossuary"

    >> This week's "helpful YEC missive" from AIG says:
    >> "Q: Doesn't it take millions of years for coral reefs to form?
    >> A: If Noah's Flood occurred only about 4,500 years ago, as the Bible
    >> indicates, then the coral reefs, such as the famous Great Barrier
    >> Reef in
    >> Australia, must be less than 4,500 years old.
    >> At one of the the Barrier Reef's underwater observatories great
    >> clumps of
    >> coral are already growing on the large anchor chains! This has
    >> certainly
    >> not taken millions of years.
    >> Also, there's some fascinating research on coral growth conducted by
    >> Australian scientists. They found that the average growth of certain
    >> corals was over a half an inch per year. Now, the deepest part of
    >> the
    >> Great Barrier Reef is around 180 feet. At this growth rate, the
    >> entire
    >> reef could be explained in less than four thousand years--which fits
    >> the
    >> Biblical date of the Flood!"
    >> Anyone know the obvious answer to this one?
    >> Burgy

    There are a multitude of easy answers.

    This type of argument is the same as those that quote modern rapid
    depositional rates as though they support a young Earth.

    Existing coral reef atolls have thicknesses up to 1,400 meters. Given
    the above estimate of coral growth rate, this would be equivalent to
    140,000 years. Now the actual upward growth rate of a coral reef much
    less than this. The accumulation of reef rock is largely controlled by
    relative sealevel rise because corals cannot actively grow above
    sealevel. That means that long term accretion rates are a function of
    sealevel rise or reef subsidence. Furthermore, coral reefs are high
    destructive environments (due to both biological and physical agents)
    in which the rate of new skeletal growth is typically balanced by

    The base of the Eniwetok atoll has been dated to the upper Eocene.

    In addition to the above, fossil reef deposits occur throughout the
    fossil record (into the Precambrian if you count thick stromatolitic
    deposits). Some of these are hundreds of meters thick.


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