Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-crg!ames!sri-spam!sri-unix!hplabs!tektronix!uw-beaver!fluke!ssc-vax!bcsaic!pamp From: pamp@bcsaic.UUCP (Wagener) Newsgroups: sci.misc Subject: Re: alternative to plate tectonics Message-ID: <21@bcsaic.UUCP> Date: Thu, 11-Dec-86 17:22:52 EST Article-I.D.: bcsaic.21 Posted: Thu Dec 11 17:22:52 1986 Date-Received: Tue, 16-Dec-86 01:00:08 EST References: <531@weitek.UUCP> <1272@cit-vax.Caltech.Edu> <1273@cit-vax.Caltech.Edu> <777@jc3b21.UUCP> Reply-To: pamp@bcsaic.UUCP (Pam Pincha-Wagener) Organization: Boeing Computer Services AI Center, Seattle Lines: 44 In article <777@jc3b21.UUCP> larry@jc3b21.UUCP (Lawrence F. Strickland) writes: > >Just recently on Public TV, there was a show that mentioned plate tectonics, >sea-floor spreading and the like. They made one very interesting statement >that I'm having a lot of trouble verifying. According to Wegner's hypothesis, >there was once a large super-continent (Pan-gaea) that split up to form the >later continents. MUCH evidence supports this. Also supported is the fact >that the current continent shapes (plus or minus a few buldges) are very >similar to what the were when Pan-gaea broke up. > >Now the show I saw contended that for North America, at least, the continent >was built up from deposition on an originally smaller continent based in >southern Canada. They called it the Canadian shelf or something like that. >They also noted that this rock PRE-DATED the formation of Pan-Gaea! > >Try as I might, I can't find any books or other sources that either confirm or >deny this. Most go back to Pan-gaea and talk about the break up and the sea- >floor spreading and subduction that has taken place since then, but nothing >that would indicate shapes of continents prior to the formation of Pan-gaea. > >Was this just a flight of fancy of the author of the show? Are there any >theories on continents prior to Pan-gaea? Where can one find this stuff?? > No, it wasn't a flight of fancy. What was being discussed was the theories of micro-plate accreation. This is work that has come out of the NW US and Western Canada studies back around 1978-1983. Most of the discussions have been going on in the geology technical journals. I don't have the references here at work, but I know that Dr.Charles A. Ross did some work in paleontology that discussed this theory and gave some supporting evidence. Other authors to look up are Zvi Ben-Avraham, Alan Cox, Amos Nur, and especially Davey Jones,Norman Silberling, and John Hillhouse (USGS). You would probably want to look up information on Wrangellia and allochthonous terranes. I do have one popular article on the subject. Overbye,Dennis, 1983, The Jigsaw Earth,Discover,april,n.4v.4,p.86-91. This gives a good description of what was covered in the tv show. Hope this helps. Pam Pincha-Wagener