Walt Brown's super-tectonics

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--The oceanic lithosphere is much less dense and much thinner than continental lithosphere, ...

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I'm assuming you meant to say that oceanic lithosphere is more dense, which it is. Typical continental crust has a specific gravity of about 2.7 (2.7 times the density of water), while oceanic crust has a SG of 3.2 (or is that 3.3).By the way, as I recall, there is a difference between what is considered "crust" and what is considered "lithosphere", although I don't recall what it is (and I did use them interchangably just now).

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Seismic imaging readily confirms this process.

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Probably the following is what you meant, but I'll elaborate. Earthquake epicenters in the subjuction zone are found to get deeper, in the continentward direction. There are the odd situations, however, where oceanic crust can be thrust over the continental crust. The oceanic crust on the continents are referred to as ophiolite complexes.Of course, I'm not supplying any links to confirm this information - I am setting myself up as an "authority" .MooseAdded by edit: TC, just a note about your message 29, where you said:

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The broken cables lay along the steep continental slope that...

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In case you didn't realize it, I just thought I'd point out that that "steep" slope isn't really that steep. You got a LOT of vertical exageration in that diagram, as shown by the vertical and horizontal scales. Not that there is anything wrong with diagrams having vertical exageration. Done all the time.[This message has been edited by minnemooseus, 12-30-2003]

In the Lake Superior basin, the nature of the volcanics is bimodal. That is, the volcanics are of either the mafic end (basalts), or the felsic end (rhyolites), with little or no intermediate volcanics. I believe the basalt:rhyolite ratio is about 10:1.Seems that I heard that the volcanics of Iceland are of a very simular nature.Rhyolite is the fine grained equivalent of granite.Moose

Upon further research on the Lake Superior volcanics, I did find reference to some andesites and also even more felsic intermediate compositions. I still think that non-basaltic, non-rhyolitic volcanics are quite minor.Concerning the Iceland rhyolites - I Googled for "Iceland" and "rhyolite". The following was at the top of the list:Geokem - Rhyolites-Trachytes

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The rhyolites of Iceland have long caused controversy, it being argued that some relic of continental crust must underlie Iceland. Comparison shows immediately this is not so. The Icelandic rhyolites do not have the elevated Cs or even Rb of orogenic rhyolites, there is no negative Nb-Ta anomaly, and the Pb is not unduly high. It is in fact just what one would expect the residuum of an Icelandic basalt to look like.

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I didn't search for info on any intermediate Icelandic volcanics.Don't have any idea if this all has anything to do with the topic.Happy New Year ( time),Moose[This message has been edited by minnemooseus, 01-01-2004]

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No. Strata is not used to date fossils - only fossils are used to date strata.

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Actually, as I recall, the usual response is the opposite. The stratagraphic position dates the fossils. Ultimately, it has been discovered that time stratagraphic units and characteristic fossils go hand in hand. So the fossils CAN date the strata.Someone else already supplied this link, but I'll repeat. I think it's the single best page I've encountered, for explaining basic geologic principles and procedures. Radiometric Dating and the Geological Time Scale
Circular Reasoning or Reliable Tools?Now back to the topic of things Walt Brown???Moose

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Professor, geology, Whatsamatta U
Evolution - Changes in the environment, caused by the interactions of the components of the environment.
"Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham