#Sea Levels?
10 messages in this thread
Hi, Chris–
Welcome to the forum section!
While the evidence may hint at disappearing oceans, it hints at oceans gone for
a longer time than human prehistory and at an earlier age, if at all.
1. The anhydrites from the Mediterranean, as Michael noted in his excellent
answer, are from 6 million years ago. I have read that the Mediterranean and
Black Seas lose more water than they receive from sources other than the
Atlantic. When the Straits of Gibraltar were closed 6 mya they dried up. I
wish I could have seen the waterfall when the Straits were reopened!!
Dates from the evidence are likely to show all the items are disconnected,
disproving any notion that we have evidence for disappearing oceans, as the
date of the Mediterranean evaporites removes them.
How thick are the Gulf of Mexico anhydrites and what date?
2. Seeming "beach sand" on the Mid-Atlantic ridge may be the only evidence that
survives inspection as far as I know, and someone else may be able to demolish
that (I am no professional in these matters).
3. I doubt limestone (as reported from the Marianas basin) is going to be
built up in any short time. To become limestone (as opposed to un-lithified
deposits of seashells and whatnot), I believe there must be some buildup of
sediments to allow lithification. Perhaps someone can tell us what the minimum
time would be; I am guessing it turns out to be comparable to the entire human
residence on earth.
4. If continental shelf canyons require missing oceans to be generated, surely
this will take a lot of time, millions of years, especially noting they seem
deeper than anything rivers have cut on land.
5. Sunken flat topped seamounts, if they are caused by low sea-levels, require
a slow decline of levels to allow time for the flattening of their tops. As
you already noted, Cretaceous fossils date some of them out of human prehistory
anyway, and separate them from Mediterranean anhydrites, to illustrate the
point that datings will be critical in dealing with the hypothesis.
5. Australia need not hinder the hypothesis or help it; as a plateau it would
still be semi-isolated.
6. If admissible as evidence at all, flood legends seem to me evidence for
non-disappearing oceans. If someone remembers floods, would they not also have
noticed the poor fishing, unemployment of sailors, and rotten weather (even
they vanish without becoming ice, the oceans moderate temperatures) before
those floods?
7. Language spreading patterns seem easier to explain without such disruptions;
see the Scientific Americans of 3/90 and 10/89 with articles about the
Indo-European languages; one of them at least (I am away from my collection) as
best I recall offers accounts of such dispersals worldwide that is at least as
easy without confusion by missing waters.
While it is fair enough to consider the evidence without requiring mechanisms,
some consequences follow no matter what the mechanism. Either (1) the water
vanished but not the salt (the water became ice on the continents, water of
hydration in rocks, or whatever), or (2) the salt vanished also (this seems to
require a wormhole or extraterrestrials to remove the water).
If the salt remained, any remnant of the oceans are horribly salty, and marine
life must have undergone an extinction that would make the demise of the
dinosaurs and their friends insignificant and likely would leave land life
gasping for oxygen (consider the rotting algae). This _must_ show up in the
fossil record, so these events must have been pre-Cambrian. If the salt
vanished also (well, at least there is no troublesome ice on the continents to
explain!), the same mechanism is going to have to leave some of the salt water
(else we have the marine extinctions again) and most of the plankton, and put
the salt water back later (Occam's razor says no fair demanding two
off-the-wall mechanisms) because volcanic water emissions and leaching of salts
are not going to do the job without ripping up the landscape quite detectably.
Even so, we have some of the air filling the vacated spaces, thinner air up on
the continents, and very interesting Oxygen-18 readings from the people trying
to measure ice age temperatures.
–Doug
Dear Doug,
Yes, thanks for the posting. I'd already raised the salinity objection myself.
And asked whether I was going too far in insisting that the only definitive
approach was to accept boring/dredging results. Anyone can argue till they're
blue in the face about topology. So, it may be a long haul, though if these
Columbia results are real and I find them, I'll post them here since several
people find this claim interesting. The floods? Well, in the paper I
referenced elsewhere it says that the last inundation of the continental
shelves was a mere 5000 years ago. That would – assuming sudden floods filling
depressions – be enough for the stuff of legends anyway. Though that paper is
a bit quick to state theory as fact. And I did read somewhere that the bulk of
the Med was dry in the Pleistocene, must look that up. A hobby of mine is
ancient (500 AD+) Welsh literature, there's a charming reference to past times
'when the sea between Wales and Ireland was narrower than it is now', which may
even be a memory of that 3000 BC inundation. NOT EVIDENCE!!!
Yes, thanks for the help. I see no way forward except to study the deep
drillings and dredgings. I expect a null result, but may learn something in
the process. Time enough to start thinking of A Very Large Alien With A Sponge
if the results were really weird, eh? BTW, that *is* supposed to be a *joke*.
Chris
Hi, Chris–
Have fun; studying even the flakiest theory may bring something worthwhile to
light.
Henri Becquerel was following a family tradition of studying fluorescent
minerals when he discovered radioactivity. It could has well have been
Atlantis legends, just so long as it caused him to bring uranium ores and
photographic plates together for a happy accident. The rest came from his
pursuit of the resulting image which a less methodical person might easily have
dismissed as a forgotten exposure of the film.
–Doug
Doug- My understanding of ocean sediments is that limestone is almost
exclusively a shallow water deposit due to the solubility of carbonate in deep
waters. Abyssal ooze tends to consist more of silicaceous tests of dead
diatoms etc.
I would suspect that any limestone found in association with deep ocean rocks
has been tranported from some other environment. Of course, I have no firm
factual data to support this position of mine. Just an undocumented memory of
the zillions of words I've read on the subject.
Michael
Hi, Michael–
If limestone is found in the Marianas basin associated with seafloor basalt as
chunks, I would simply ascribe it to glacial rafting or some such trick. If it
is in large continuous beds, it would suggest a near-emptying of that part of
the ocean, but even in that strange case, I am guessing the time it would take
to form would be too long to fit with the hypothesis that the events took place
in human prehistory. I expect to learn that the dates of all these strange
things are not coordinated, killing the hypothesis but leaving some interesting
questions.
If the limestone is bedded, what else might cause it? Perhaps a massive dose
of CO2 in the atmosphere dissolving in the oceans? Might the generation of
large igneous provinces have put enough extra CO2 into the atmosphere and thus
the oceans to overcome this solubility problem and form limestones even in the
deeps? What happens if there are no shallow seas worth mentioning? Might
carbonate be "forced" to saturate the deeps and allow limestone to form there?
Again, the dates may kill these hypotheses, as might the lack of bedding.
–Doug
Wormhole? Must be a Star Trek fan here.
Hi, Todd–
Guilty as charged! But I knew of wormholes well before their mention in the
first Star Trek movie; I read lots of science fiction as well as science.
Unfortunately, geology fiction seems scarce – only a couple of short stories
among thousands come to mind as involving geology (as more than a side issue)
unless one counts Journey to the Center of the Earth or Atlantis stories, which
are more like bypassing geology.
–Doug
Wormholes? Why, I bet there are people out there who collect nothing but
wormholes. I've found some interesting ones in the field that I've wished I'd
taken home, in hindsight. I may go back to retrieve them someday!
When I was a student living in New Mexico there was this sandstone that had
circular, reddish spots which could be found on some specimens. Some theorized
that they were at one time wormholes that had latter been filled in or perhaps
even the remains of the worm itself.
Yes, I've definitely seen wormholes, too. I've got an ammonite with a clear
hole in it, I found it in situ, and the wormhole was "up". At a site in
Kansas, as this shale eroded, the worm holes were still in place, standing like
rib bones. Scared me for a second there, thought I'd found something big. 🙂
The shale was grey, the wormholes filled with white clay, now hardened to
stone.