Brett Aubrey  wrote or quoted:
> "Tim Tyler"  wrote in message
> > Brett Aubrey  wrote or quoted:
> > > > On Sun, 12 Sep 2004 18:23:23 +0000 (UTC), Tim Tyler


> > > > >Quite a few OOL scenarios put the OOL on the ocean floor.
> > > > >Others invoke evaporative tidal pools.
> > > > >I'd say that the odds were that the water was pretty salty.
> > >
> > > I was aware of thermal vents and tidal pools; but thought there might
> > > fresh water scenarios based of my "stunning logic"
 ;-)  that I hadn't
> > > heard about. [...]
> >
> > Not impossible.  Life /could/ have begun in fresh-water lakes, if
> > conditions there have some particularly OOL-favourable characteristics.
> 
> Another of the potentially favourable characteristics that I had thought of
> is the presence of clays around many rivers and lakes.  I gather some OOLs
> give clays an early role and in my experience, there isn't much clay-like
> material around oceans, which I see tending to be more sandy or rocky.
> FWIW.

The clays generated in rivers *have* to go somewhere ;-)

As to why most beaches are sandy (or rocky) - rather than covered with 
clays - I'm not /entirely/ sure of the reason for that - but I suspect
the two main factors are:

* When an aggregate medium is shaken, the large particles rise to the
  top - while the small particles sink to the bottom;

* Material on beaches tends to have been recently derived from the
  action of waves on rocks - and consequently has not yet been fully 
  pulverised;

Rest assured that - on the ocean floor - clays dominate:

``For example, on the ocean floor clay dominates sediment deposition in 
  the deep ocean far from shore, whereas sand is commonly deposited 
  closer to shore in shallow water.''

 - http://tinyurl.com/5hxhd
-- 
__________
 |im |yler  http://timtyler.org/  tim{at}tt1lock.org  Remove lock to reply.
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 9/15/04 12:07:05 PM