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RE: Clastic or Carbonate

--- James Farlow <farlow@ipfw.edu> schrieb:

> If push comes to shove, though, take clastics if you
> are interested in
> dinosaurs, other terrestrial vertebrates, and land
> plants; and carbonates if
> you are interested in anything else.
> I second Tom's recommendation, albeit with a minor
> proviso:  If per chance you are interested in
> dinosaur footprints, carbonates might well be of
> interest.  A lot of very important tracksites are in
> limestones, and knowing something about said
> carbonates might be useful in interpreting what the
> beasts might have been doing as they stomped around
> on the mudflats.

Not to forget karst.

"Clastic vs carbonate" is actually a bit comparing
apples with dromaeosaurids. The first deals with
physical processes - Clastic is how rocks are broken
into pieces and what happens to these, think
sandstone, breccia, siltstone - whereas the Carbonate
deals with chemical properties - basically, limestones
and their relatives.

A rock can be both, either, or neither; Some months
ago I was poking around underneath a paleo-cliff,
where the rock was mostly a conglomerate of coarse
fragments (clastic) of an ancient reef's limestone

Though clastic and carbonate rocks are both usually
sedimentary in origin, there is not *that* much
overlap in real life: really fine-grained (= finely
clastic) carbonate rock tends to dissolve rather than
to sediment.

That being said, I totally agree with the consensus,
though you might want to find out more about the
carbonate field trips before you sign up for both*. In
any case, clastics for anything on land and a lot of
marine stuff too. Carbonates for marine invertebrates,
karst and/or fun.

All the best,


[*] It's not necessarily the Caribbean. Some people
like walking through karst, others hate it.

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