Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.7.0.8 $; site convexs Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcs!convex!convexs!ayers From: ayers@convexs.UUCP Newsgroups: net.sci Subject: Re: Geology (Great Lakes) Question Message-ID: <25500005@convexs> Date: Wed, 14-Aug-85 11:34:00 EDT Article-I.D.: convexs.25500005 Posted: Wed Aug 14 11:34:00 1985 Date-Received: Sun, 18-Aug-85 04:38:05 EDT References: <150@ho95e.UUCP> Lines: 32 Nf-ID: #R:ho95e.UUCP:-15000:convexs:25500005:000:1287 Nf-From: convexs.UUCP!ayers Aug 14 10:34:00 1985 /* ---------- "Geology (Great Lakes) Question" ---------- */ >Does anybody out there know about the origin of the Great Lakes >(and have any newer theories come out lately, particularly >with regards to plate tectonics and hot spots)? > >I'm wondering if some plate tectonics might be involved here. The only >other inland areas below sea level I can think of had tectonic causes >(Death Valley, Dead Sea, Caspian Sea, Loch Ness). Might the Great Lakes >be the remnant of a failed rifting (which was much later covered by ice)? For the latest on plate tectonics, see the most recent issue of National Geographic... > If you look at them (in particular, Superior, Michigan, and Huron), > they are *very deep*. For instance, Superior is 1300 feet deep. >>Sorry, but most of the Great Lakes are *very shallow*. It >>is hard to find a place in Erie, Superior, and Huron more >>than about 100 feet deep, and most of Michigan is less than >>200 feet deep... Time magazine, August 12, 1985, pg. 49: "...on the first submarine exploration to the bottom of one of the world's biggest bodies of fresh water, Lake Superior...using the _Sea-Link_, they have been able to plunge right to the bottom. The deepest point: 1,330 ft." Well, that's one mystery less... blues, II