I am catching up on some literature reading in geology(I am about 2 years
behind in reading my AAPGs and will catch up this summer. I ran into the
following abstract. The abstract says:
ìNew data from the central Texas Coast indicate that the middle Holocene sea
level ws higher than today. The most important site consist of
shore-parallel ridges in the mouths of tributaries to Copano Bay (and other
bays). Which attain elevations of + 2 m to +3 m, and are underlain by ~2 m
of bioturbated sand and silt with shell hash. Abundant calcareous forams
within these deposits indicate subtidal to intertidal depositional
environments, whereas 14C ages from foram test indicate middle Holocene
ages. These ridges are interpreted as shoals and spits that formed in the
mouths of the then-flooded bay tributaries, and they are now emergent due to
more recent sea-level fall. Accordingly, they indicate that middle Holocene
sea level was at + 2 m or more.î
ìA number of mainland landforms are now thought to record
this highstand.
Most important among these is an extensive beach ridge plain. Although long
considered to be part of the ëInglesideí shoreline from the last
interglacial period, this Holocene beach ridge is underlain by >4 m of
unweathered, massive to stratified sand that rests unconformably on
weathered kmís along the mainland shore (in between Matagorda, San Antonio,
Copano, and Corpus Christi Bays), and can be 1-3 kmís in width. Beach ridge
plains are interpreted to represent progradation after maximum highstand,
and during sea-level fall to present elevations or lower.
ìThe middle Holocene highstand correlates to similar events at many low
latitude and/or southern hemisphere sites, but may be the first highstand
identified along a non-rebounding, non-uplifting coast in North America.
Interpretation of what is sure to be a controversial highstand is bolstered
by recognition of its imprint on landscape evolution, especially the
extensive mainland attached Holocene beach ridge plains.î
Amy E. Carter, Michael D. Blum, ìMiddle Holocene Sea-Level Highstand at +2 m
and Evolution of the Texas Coast,î AAPG Bulletin October 2000, p. 1674
In order for this to have occurred, more of the arctic and Antarctic ice
must have melted in the past than is melted today. If so, it melted on its
own without the help of a single automobile. Now, I don't know what kind of
responses to this paper are out there. Maybe I will run into a refutation,
maybe I won't. The observations are interesting in any event because of the
implications.
First the middle Holocene is about 5000 years ago. It would explain why
southern Mesopotamia might have been underwater at that time as I noted in a
note to Mike Satterlee. But it wouldn't cause a flood as the rise and fall
of sea level is exceedingly slow--slower than the growth of your
fingernails.
glenn
see http://www.glenn.morton.btinternet.co.uk/dmd.htm
for lots of creation/evolution information
anthropology/geology/paleontology/theology\
personal stories of struggle
This archive was generated by hypermail 2b29 : Fri Jul 05 2002 - 16:20:19 EDT