Re: Mesozoic snow?

[Phil Bigelow <bigelowp@juno.com>]

There are varved lacustrine units known from the Mesozoic, but I am
unaware of any  varved Mesozoic sediments unequivocally caused by ice.

However, there are dropstones known from some Mesozoic marine seds. 
(although some workers have argued that these stones were not ice-rafted,
but were instead entrained in the root ball of floating logs).  I can't
find the reference(s), but I'll look again.  The incidence of these
purported Mesozoic dropstones deserves much more scientific scrutiny than
it has received in the past.

<pb>
--

On Sat, 11 Jun 2005 23:31:46 -0600 frank bliss <frank@blissnet.com>
writes:
> Are there no varves preserved in the record for the Mesozoic?
> Frank Bliss
> MS Biostratigraphy
> Weston, Wyoming
> On Jun 11, 2005, at 10:57 PM, Swift Claw wrote:
> 
> > on 6/11/05 9:57 AM, Phil Bigelow at bigelowp@juno.com wrote:
> >
> >
> >> But freeze-thaw cycles CAN be
> >> preserved in modern environments, and the discovery of polygonal 
> soil 
> >> in
> >> a Mesozoic formation would/will be an important find.  AFAIK, 
> such a
> >> discovery hasn't yet been made.
> >>
> >> The best place to look for polygonal paleosols in Mesozoic rocks 
> 
> >> would be
> >> in Australia, northern Canada, northern Siberia, and Alaska 
> (duh).
> >
> >
> > But the time I see something like that happen is mainly in the 
> summer 
> > when
> > the rains hit the dry soil and then dry again quickly...
> >
> > ~Tiffany Miller
> >
> >
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>