[meteorite-list] Canyon Diablo & nomenclature...
From: Jeff Grossman <jgrossman_at_meteoritecentral.com>
Date: Fri May 13 10:06:46 2005 Message-ID: <5.1.0.14.2.20050513081722.020eefd8_at_gsvaresm02.er.usgs.gov> Here's what I could learn in a brief review of literature I have. Others know much more about this than I do. GK Gilbert published a paper in Science, "The Origin of Hypotheses, Illustrated by the Discussion of a Topographic Problem", Science, Vol. 3, No. 53. (Jan. 3, 1896), pp. 1-13. This was the text of his presidential address to the Geological Society of Washington in 1895 (I hope my presidential address to GSW last year better stands the test of time). In this paper, he tests his own hypothesis that the crater formed by the impact of a "star". After a two weeks of field work involving topographic measurements and magnetic surveys, he could not find evidence to support his hypothesis, which he thought predicted there would be a large, buried, magnetic mass beneath the crater: there was no large magnetic anomaly, and the volume of ejecta perfectly matched to volume of the hole, leaving no room for a 1500-foot diameter buried spherical object. (He does leave open the possibility that the crater could still have been formed by a "plum-pudding" object with iron masses embedded in stone, which is really interesting because that's now one of the prevailing ideas about how IAB irons really did form!). Anyway, at this point, he abandoned his intuition and went looking for alternative ideas, which turned out not to be very good. Although Gilbert couldn't find the evidence to support his hypothesis, the impact idea was his. In 1905, Barringer and Tilghman published back to back papers in the Proc. Acad. Nat. Sci. Phila., refuting Gilbert's fall-back explanation that the crater was due to a steam explosion. They made lots of good observations consistent with impact, but both of them still accepted Gilbert's idea that there had to be a buried meteorite if it was an impact crater. They just weren't willing to overlook all the other evidence that pointed to impact, as Gilbert did. It wasn't until 1907 that Herman Fairchild published (GSA Bull. 18, 493-504, a paper read before the Society on 12/29/1906) the idea that the projectile might be travelling very fast and therefore only had to be a few 100 feet across. This made it less likely that a buried mass would be found, and so took care of Gilbert's big objection. Fairchild also talked about renaming the crater "Meteor Crater." Interestingly, he notes that "for some time the U. S. Post Office located near Mr Holsinger's camp [near the crater rim] with the name Meteor, Arizona, gives an official standing to the word [meteor]." So somebody was using this name before Fairchild. jeff At 07:37 AM 5/13/2005, MARK BOSTICK wrote: >Hello Ron and list, > >Ron noted, "The name "Meteor Crater" was first formally proposed...on >December 29, 1906...." > >Barringer was calling it Coon Mountain at this time, so the reference >appears to be accurate. My question was however when was the crater >officially scientifically recognized as a meteorite crater. But I guess >there isn't a clear answer. The USGS was claiming the crater to be a >steam blowout in 1906. > >For locals, it was pre-1901, when written reference of the crater starts. > >Does anyone know if the USGS wrote any crater origin papers on the >structure before Shoemaker? > >Clear Skies, >Mark > > >______________________________________________ >Meteorite-list mailing list >Meteorite-list_at_meteoritecentral.com >http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Fri 13 May 2005 10:02:13 AM PDT |
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