Wow - my mind went off the deep end on this one. Cold water dissolves
carbonate...

What if - the typical very tall pacific mountain that has receded and
formed a coral
reef on the rim and this rim becomes very tall over millions of years.
The young build on top
of the old reef and move upward as the mountain recedes due to the
massive weight

Then at the critical carbonate compensation depth the 'mother' reef
begins to dissolve.

This then begs the solution does the reef remain stable enough and just
settle and
the top continues to grow.

Perhaps this hasn't happened yet, just pending a wall disaster or island
sinking.
Interesting concept.

I suspect the typical reef grew in more recent times and hasn't reached
the abyssal depth.

Thanks for shaking up the gray matter - My thought was Kwajalein, an old
and very large
(70 miles on the diagonal ). I have to find my SAR maps - maybe depth
sounding in the
lagoon where the peaks were might help sort this out. Off the south
(ocean side) edge
is very deep for the area around there. Not abyssal like "The Trench".

Martin

Andrew Grebneff wrote:
> <snip>
> In very cold water calcium carbonate is more soluble than in warm
> water; therefore shells from these areas tend to exhibit corrosion
> (this is not erosion) problems, often severe. This also happens in
> deep (and so cold) waters. Which is why forms living there have
> evolved periostracum to resist this.
>
> Go deep (and cold) enough into the abyssal region and you reach what
> is called the carbonate compensation depth, where cold and pressure
> combine to dissolve all carbonate... below this depth no forams,
> coccoliths or pteropod shells accumulate on the bottom, as they
> dissolve.
> --
> Andrew Grebneff
> Dunedin
> New Zealand
> Fossil preparator
> Seashell, Macintosh, VW/Toyota van nut
> ‚ Opinions stated are mine, not those of Otago University
> "There is water at the bottom of the ocean" - Talking Heads
>
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--
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/

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