4. If almost all limestone was produced organically in shallow seas, and since today, organic limestone is primarily produced within 30 miles of the equator, why is it that limestone layers an cement are not concentrated near the equator, but found at all latitudes?
See, this is the kind of statement that Walt makes that should raise a red flag and get you to toss the book away.
Are the Great Barrier Reefs within 30 miles of the equater? How about Gray's Reef off the coast of Georgia? How about those in Florida or Baha, those in the South Pacific or off South Africa?
In addition, this ignores other sources that lead to limestone like the diatoms that live in waters all over the world.
3."If a microscopic limestone crystal grows in a magnesium-rich solution, magnesium ions will, under certain conditions, occupy or replace exactly half the calcium ion locations in limestone, forming a common mineral called dolomite"
Since dolomite is not secreted by any known organism, where did the necessary magnesium come from to create the dolomite?
Well, if you look at a periodic chart you will find that magnesium is in the same family as calcium, and higher in the family. It is a common part of sea water so it's not surprising at all.
AbE: In addition, magnesium ions are found in almost all living
organisms.
This message has been edited by jar, 03-19-2006 12:09 PM
Aslan is not a Tame Lion