CompuServe Thread

#Sea Levels?

4 messages in this thread
#126405From: Chris TinsleyMar 29, 1994 10:22 AM
Dear All, I will admit to a tendency to rather enjoy counter-culture books with whacky theories, it's a sort of secret vice; and often quite enjoyable to see where they've gone wrong and try to establish why the book was written – and published. Quite a few years ago I read one such book, most of which I could see was incorrect. But there was one suggestion in it I've not been able to sort out to my satisfaction, maybe because I don't know where to find the original data. And various oddments I pick up, like the recent TV report that large quantities of cocaine have been found in an Egyptian mummy, keep reminding me about it. What I'd like to do is lay out the evidence claimed, and ask if it is just plain wrong, what sources I could use to check on it, or ask what the consensual interpretation of it all is. I have had a look around the geology shelves in a large public library, but this cursory search hasn't revealed much in the way of answers, and I don't really know where to look in the local University library. So this is an 'umble request for 'elp. It is not a disguised plug for a whacky idea. If the subject has been covered here already, perhaps someone can guide me. The idea is that within human prehistory – let's say before 10,000 BC and after 100,000 BC – sea level changes were so great as to reveal the ocean floors, and that this happened perhaps several times. When the derisive laughter has settled, could I ask that it be accepted that it is a waste of time – it wasted a great deal of time during the 'continental drift' controversy, as I well remember – to discuss mechanisms or their absurdity. The only way to go forward, it seems to me, is to concentrate on the (supposed) evidence in favour – and against. The proposed mechanism was that the water was piled (as ice) ten miles or more high on what are now the continents, and I can see many arguments against that – and a few in favour to be fair. But all that IS, strictly speaking, irrelevant. Here is the 'evidence' for comment: 1. That the Glomar Challenger brought some unusual core samples from drillings of sea/ocean floors: anhydrites from the Mediterranean and the Gulf of Mexico, the latter being a bit difficult to explain. 2. Publication by Columbia U of oceanic findings: prehistoric beach sand on the slopes of the Mid Atlantic Ridge – rounded grains and pebbles suitably graded, one such finding being now inder two miles of water, another nearly 3.5 miles down. These included (I can't keep saying 'are supposed to have') foraminifera shells typical of shallow water. Alternating layers of such sand and typical abyssal deposits. Mudstone. Terrestrial-type sedimentary rocks with apparent glacial striations. 3. Limestone found when drilling (dunno who by) in the Maraianas Basin, at 20,000 feet. The suggestion that alternate layers of limestone and abyssal deposits are common in ocean floor material, and that limestone should be formed only in shallow water(?). 4. River (V-shaped) canyons, running down the height of the continental shelves: the Congo River, including the statement that Dr F P Shepard of Scripps found a 'river delta' on the ocean floor; the Hudson, the mid-ocean canyon; others, notably W Africa. 5. A discussion of how such a hypothesis would still permit the isolation of Australia. 6. Sunken flat-topped sea mounts at a wide variety of depths. 7. Legends of floods worldwide. Atlantis. Similarities of architecture. Similarities of language. Isolated pockets of populations like Basques etc. Bird migratory paths following (relatively) shallow water areas in oceans. Dredging of terrestrial fossils from the Grand Banks(?). Sudden emergence of Egyptian architecture and subsequent decline thereof(?). Odd customs like the 'couvade' being practiced on either side of the Atlantic. Lots of stuff like this. Well. First, I'd ask whether things have moved on in the past 15-20 years. I'd like to know if there is solid evidence of continuing human existence over the period in question in all the areas of the world not affected by glaciation, because I think that would go against this idea – the continents would not be nice places even if they were not iced over. I'd like to know if this evidence is faithfully represented, and IF it is, then how it is explained. The canyons do seem to be a problem, the only explanation of them which I found looked suspiciously like explaining away rather than explaining. I did look at a map of human blood-types, it didn't seem to help much either way. I used the word 'intriguing' on the physics forum, and was dismissed by one respondent as credulous and naive. I don't think I am, I'm just puzzled by something I can't straighten out in my mind. Chris /ex
#126454From: Todd FrankMar 29, 1994 9:27 PM
In Geology there are many facts. It is always interesting how many different people can take the same facts, learned through scientific observation and come to totally different conclusions. Twenty years ago nobody would have believed that the Medditerean sea (sorry about my spelling) has repeatily dried up to the point where it was very similiar to the Death Valley of CA. They know for a fact since its bottom has been cored and the same evaporite minerals and surface structures can be found in these cores. There is no other way they could have formed. People know it has happened but they don't really know how. Something I always remember, I call it the story of Wegner. When Wegner first proposed the theory he called Continental drift which has since evolved to Plate Tectonics he was laughed at and ostricized by the scientific community of his day. Anyone who tried to teach it risk being fired or not hired at all. Many jobs were lost by those who first championed the theory. Now practically every Geoscientist believes it, some of whom are just as dogmatic in their beliefs. Todays wacky idea could be tomorrows commonly held belief.
#126482From: Chris TinsleyMar 30, 1994 2:55 AM
Dear Todd, Many thanks for your reply. Yes, I well remember the 'Drifter' controversy, and was amused to see recently that Nature – which I despise in certain respects – is rewriting the story as some kind of friendly debate. As a small boy in the fifties I read all about it, saw that the continents in fact do NOT fit together, and made a globe with the continents thus accurately represented. They fitted very much better than the Mercator maps, of course, but I still wince to recall the treatment I got when I eagerly displayed my little treasure at my school. None of which proves ANYTHING about the sea-level idea. With that I am at the same point I was with "cold fusion" years ago. That took me years to decide on, because there was a clear clash between logic and my knowledge of physics – which beats my knowledge of geology hands down. I did have one University year on it as a 'half subject', so I can at least (just about) follow the jargon, but that was thirty years or more ago! On this one I'm floundering because I just don't know where to start looking. I have pretty much decided to try to get to the bottom – haha – of this one, and it will probably take me years to decide. I'd hoped to get some leads to sources, or some info of substance, that might save me quite a lot of time. The whole thing may just be a tissue of nonsense and distortions. I'd just like to make my own mind up, and without a great deal of raw data I can't do that. For a start, is it true that the Gulf of Mexico has evaporites too? Chris
#126501From: Chris TinsleyMar 30, 1994 10:28 AM
Encouraged by your words, I decided to jump in at the deep end and spent a happy hour in th U Lib. Fascinating, this clearly has Huge Hobby Potential! Obviously a quick look is no basis for comment, but that's not going to stop me. Sources (unnoted) were one coffee-table book, one about sea-mounts, some bound papers on contintal margins, and sight of the Glomar reports – not looked at yet, they fill shelves. So, it seems the sea mounts of the Pacific are a sunken Hawaii, kms down. But they say that Cretaceous fossils are there and no coral. Must check when coral first appeared. Quoted as having been a pre-Plate Tectonics problem, solved by same. Implication: they're very old and probably not relevant. Fine, scratch them (for now). Only one other thought, do people admit to problems only after there's an answer…? The coffee table book (sneer) had a diagram of the Atlantic Ocean as if drained. Very strange, the canyons were far more dramatic than I'd expected. Especially one running from Gibraltar most of the way to the Mid Atlantic Ridge. Stranger still was that the diagram was annotated with all the features described except the one second most dramatic after the M I R – the canyons. The actual papers with sonar raw data were extraordinary! These canyons run right down the shelf off Africa – the only area I checked. They are very steep-walled, some have STEPPED walls, some are FILLED. Yes, there IS what looks just like a delta at the end of the Congo canyon, right on the abyssal floor. The papers were excellent sources of data, with very sketchy conclusions, I like that. Any possible origins of the canyons were not mentioned, though I've only scratched the surface of the papers. Conclusions? Well, obviously none. But I'm far more interested than I was, it is one of those cases where "it's obvious at first glance that the Atlantic basin was once nearly all dry land" haha. No, of course it isn't, but there is something very strange indeed about all this. Unless somebody knows better? Great fun, anybody want to join the hunt? Chris