H.W - hawkwind and paleoclimatology

[Henderson Keith]

Eric hat gesagt...

> On Tue, Mar 04, 2003 at 10:03:09PM -0000, Jill Strobridge wrote:
> > From: "Sean McMahon" <dr_technical at MCMAHON66.FSNET.CO.UK>
> > >
> > > IPSWICHIAN!!
> > >
> > Goodness me - that dates you [...]
> > about 130,000 years ago
>
> 250,000,000 more like.
>
> The Cenozoic epochs are all in "-ene".  If it's "-ian", it's
> gotta be Paleozoic.

Nei...this "Ipswichian" is not an 'epoch' or 'era,' but rather
a Quaternary term, and essentially then, a 'period.'  And those
are different across the globe, which can cause some confusion.
So 130 ka is correct, although in the literature one normally
refers to this as the "Eem" or "Eemian" period, which is from
some other part of Europe (?).  And the American-derived "Sangamon"
(which is essentially the same) has seemingly gone out of favor.
I think that had to do with the fact that it referred to *all* of
Marine Isotope Stage 5, whereas Eemian was attached only to
MIS 5e, which is the true interglacial lasting until about 110
ka.  And so 'Eemian' and 'Wisconsinan' are often mixed together
which is kinda weird but it's accepted.

The glacial periods (colloquially "Ice Ages") are similarly
regionally-distinct-yet-generally-simultaneous, so that the
American 'Wisconsinan' is coincident to the Alpine 'Wuerm' and
the NEurope/Fennoscandian 'Weichselian'.  Nice that they all
start with 'W.'  Back into the more distant past, the US sequence
WIKN (Wi, Illinoisan, Kansan, Nebraskan) is then reproduced by
the Jura-derived alphabetically-inverted WRMG sequence (Wuerm,
Riss, Mindel, Gunz).  Before that, no glacial-geomorphological
evidence has survived, and so that even though there were still
ice ages further back, they weren't given geographical names.
And so we call them MIS 12, 14, 16, etc.  How boring.

Of course, it was the polar (and then eventually high-elevation
tropical) ice cores that put all of these into an accurate time
frame and confirmed global synchroneity (to a first order, given
some discrepancies of chronology of glacial onset across the
equator from 30N-30S that I won't get into).  And now I have heard
rumours that the new EPICA Antarctic core (based on modelling that
may well be a crock, I should point out) *may* have 850,000 years
of continuous history (Vostock ended at 475,000 years BP, since
they came upon a lake under the ice).  And so that would predate
the onset of the 100,000-yr. ice age cycle (by about 150,000 years)
and thus would be quite an important feat (if true).  And if that
team had hired me, I'd live in Tromso, Norway at the moment.  And
be an alcoholic by now.  :)

YHRPC...Grakkl (FAA)