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From: bob@islenet.UUCP (Bob Cunningham)
Newsgroups: net.origins
Subject: Re: The Scientific Case for Creation: (Part 38)
Message-ID: <1372@islenet.UUCP>
Date: Wed, 10-Jul-85 05:12:16 EDT
Article-I.D.: islenet.1372
Posted: Wed Jul 10 05:12:16 1985
Date-Received: Thu, 18-Jul-85 03:39:42 EDT
References: <396@iham1.UUCP>
Distribution: net
Organization: Hawaii Institute of Geophysics
Lines: 64

Using a slightly-higher figure (based upon sediment flux measurements in
major river systems), we're looking at an average rate of erosion of around
6 cm of continental surface (at a density of 2.4 gm/cm^3) per 1,000 years.

Deposited oceanic sediments being less dense (say .8 gm/cm^3, dried
density)  and factoring in the ratio of 3/7 continental surface area/ocean
bottom area, this would produce roughly 6 cm of ocean-bottom sediment every
1,000 years.

At this rate, the continents (which are, on the average, only 840 meters
high) would be worn down in roughly 50 million years.

These sorts of back-of-the-evelope calculations are interesting, but
completely ignore several different major processes:  volcano building
(volcanic eruptions produce roughly the same order of magnitude of material
as the erosion figures), folding & upthrusting, and isostatic adjustments.
You just can't ignore these other processes.

Nor, can you ignore the extensive variations in erosion (64% of Australia
doesn't drain into the sea, while 10% of North America does); and that the
major portion of the sedimentary debris ends up on the margins of the
continents (only about 6% of the eroded sediment actually makes it to the
deep ocean).

Extensive evidence indicates that much of the continental material is quite
old, while the current ocean bottom is relatively young (a few hundred
million years).  A puzzle that's been resolved by plate tectonic studies.

>        71.  Over twenty-seven billion  tons  of  river  sediments  are
>             entering  the  oceans  each  year.  Probably, this rate of
>             sediment transport was even greater in  the  past  as  the
>             looser  top  soil  was  removed and as erosion reduced the
>             earth's relief. But even if erosion has been constant, the
>             sediments  that  are  now  on  the  ocean floor would have
>             accumulated in  only  30  million  years.  Therefore,  the
>             continents and oceans cannot be one billion years old [a].
>        72.  The continents are being eroded at a rate that would level
>             them  in  much  less than twenty-five million years [a,b].
>             However, evolutionists believe that the  fossils  of  land
>             animals  and  plants that are at high elevations have been
>             there for over 300 million years.
> 
>        73.  The rate at which elements  such  as  copper,  gold,  tin,
>             lead,  silicon,  mercury, uranium, and nickel are entering
>             the oceans is very rapid  when  compared  with  the  small
>             quantities of these elements already in the oceans.  There
>             is no known means by which large amounts of these elements
>             can  precipitate  out of the oceans. Therefore, the oceans
>             must be very much younger than a million years.

Reef-building coral incorporates uranium into their CaC02 extensively,
providing a "sink" for uranium (and CA, Sr, Ba, Ra as well).  Lead is
virtually insoluble in the oceans, and thus they essentially contain none
(it stays in particulate form).  Elements with a +2 valence (notably Ni,
Co, Cu) show up in relatively high concentrations in deep sea sediments,
apparently precipitating out rather rapidly.  Silicon is quite effectively
used by a number of species of diatoms & radiolarians, and the settling of
their skeletons is probably the major "sink" in the occeans (for at least
some of the species, silicon seems to be bio-limiting: give them more
silicon, and they'll glady use it, grow, prosper, and fairly quickly die
and deposit it).
-- 
Bob Cunningham  {dual|vortex|ihnp4}!islenet!bob
Honolulu, Hawaii