Cliff wrote in
:

On 28 Sep 2005 03:57:22 GMT, D Murphy wrote:

Cliff wrote in
news:v8jij15191nkou21lg2fg28h4plf94ng4a@ 4ax.com:

On 26 Sep 2005 23:21:26 GMT, D Murphy wrote:

So you say, CO2 is a greenhouse gas? Of course it is. The
concentrations seen at that time (seen by examining carbon content
of sedimentary calcium carbonate)

Umm ..... How does that tell anything?

If you are truly interested take a class or read a book. I'll provide
a link once you write a two part essay explaining isotopes, and the
various ways that scientists uses carbon isotopes.

Do you have Carbon & Calcium confused again?
C12 & C13 are fairly stable, C14 has a half life of
~5760 years.
C14 dating is only good for about 50,000 years into
the past. Even if. When porous things (like sediments)
have things like water perhaps flowing thru them
newer carbon 14 can replace part of the older carbon ....
Hence C14 dating is not very good under such conditions.

What does carbon dating have to do with anything I wrote?


How old were those sediments again?

Re-read the OP.


Now, Calcium Carbonate is Calcium Carbonate ...
the ratios of Calcium to Carbon seem a bit fixed ...

Take my original advice.g



--

Dan