[meteorite-list] Dry Lake Stewnfields??
From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Thu Apr 22 10:17:48 2004 Message-ID: <40.38882ffd.2d0fe8ea_at_aol.com> --part1_40.38882ffd.2d0fe8ea_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Hi John, I think if we get back to basic definitions, a strewn field is an ellipsoid shape caused by a mid air explosion raining down material, as far as I understand. What happens afterwards to the material is irrelevant. And the strewn field is a geometric representation fitted to the fall in practice, not the actual individual stones. If some gets moved, picked clean, the boundaries of the strewn field can't change, from their original definition. Perhaps some of the hunters among us will not see it that way...as strewn tends to bring a connotation of waltzing in and cleaning up. And an empty strewn field sounds odd... So I would think that the technical "set one straight answer" you want is that: Mathematically it takes at least four border points to make an ellipse, but to actually be able to fit one with any confidence in an area, you need plenty more, to fill in the area. A neat statistical definition seems impractical, so it will come down top the field researcher's opinion. If the one who did the research wants to call it a strewn field and their is evidence for a mid air explosion...then we should have one. And if there are a few rocks...in the desert, or in Chicago, and the principal investigator(s) don't feel there is enough for an ellipse, then its not, because they say so. An it is a good assumption if we happen upon an old scattered field, we can say...this might be a strewn field, but lacking a good cause-effect ellipse explanation there can't be a right answer for lack of data. In the end one can probably collect opinions on this until blue in the face...and who calls what a what...but for what? Strewn fields are simply human categories so we can make sense out of natural events that don't have to conform to our neat, ways of nomenclature. Just like the concept of a species or a race in biology. You know an obvious one when you see it...but when you start taking it as gospel and look at the limits of the definition, the whole think breaks down, and mass consensus isn't reached...plus air resistance already distorts a strewn field to a researcher. So there has got to be a little eyeballing going on since tiny particles don't fall nicely. If it looks like a strewn field, (tastes like one), ... Sipping my hot chocolate...Saludos Doug Dawn Mexico En un mensaje con fecha 12/15/2003 10:17:15 PM Mexico Standard Time, j.divelbiss_at_att.net escribe: > > > To Rob, Bob, Adam, and others: > > Recent finds from the Nevada dry lakes were grouped in a small area within a > > dry lake. The finding of three apparent pieces from same fall created a > description by Adam that these finds might constitute a new strewnfield. > > Questions/observations in regards to desert strewnfields. > > 1. Obvious groupings of fallen masses would make the likelihood of the area > being a meteorite stewnfield. Do multiple finds in desert locale usually get > > described as a stewnfield? > > 2. Does the fact that many rocks get moved around in these environments take > > the strewnfield idea down a notch with rocks being scattered?...or does > their > proximity within the bounds of normal surface movements qualify them to be > still within the original strewnfield? > > 3. Is the idea of stating a location has a new strewnfield more about this > location being a new place to find more than one meteorite of the same > apparent fall?...and not so much about the actual fall characteristics? > > I guess I'm just curious about the use of word strewnfield in this case? > > Yearning to be set straight, > > John > > > --part1_40.38882ffd.2d0fe8ea_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable <HTML><FONT FACE=3Darial,helvetica><HTML><FONT SIZE=3D2 PTSIZE=3D10 FAMILY= =3D"SANSSERIF" FACE=3D"Arial" LANG=3D"0">Hi John, I think if we get back to=20= basic definitions, a strewn field is an ellipsoid shape caused by a mid air=20= explosion raining down material, as far as I understand. What happens=20= afterwards to the material is irrelevant. And the strewn field is a ge= ometric representation fitted to the fall in practice, not the actual indivi= dual stones. If some gets moved, picked clean, the boundaries of the s= trewn field can't change, from their original definition.<BR> <BR> Perhaps some of the hunters among us will not see it that way...as strewn te= nds to bring a connotation of waltzing in and cleaning up. And an empt= y strewn field sounds odd...<BR> <BR> So I would think that the technical "set one straight answer" you want is th= at: Mathematically it takes at least four border points to make an ell= ipse, but to actually be able to fit one with any confidence in an area, you= need plenty more, to fill in the area. A neat statistical definition=20= seems impractical, so it will come down top the field researcher's opinion.&= nbsp; If the one who did the research wants to call it a strewn field and th= eir is evidence for a mid air explosion...then we should have one. And= if there are a few rocks...in the desert, or in Chicago, and the principal=20= investigator(s) don't feel there is enough for an ellipse, then its not, bec= ause they say so. An it is a good assumption if we happen upon an old=20= scattered field, we can say...this might be a strewn field, but lacking a go= od cause-effect ellipse explanation there can't be a right answer for lack o= f data. In the end one can probably collect opinions on this until blu= e in the face...and who calls what a what...but for what?<BR> <BR> Strewn fields are simply human categories so we can make sense out of natura= l events that don't have to conform to our neat, ways of nomenclature. = Just like the concept of a species or a race in biology. You know an=20= obvious one when you see it...but when you start taking it as gospel and loo= k at the limits of the definition, the whole think breaks down, and mass con= sensus isn't reached...plus air resistance already distorts a strewn field t= o a researcher. So there has got to be a little eyeballing going on si= nce tiny particles don't fall nicely. If it looks like a strewn field,= (tastes like one), ...<BR> <BR> Sipping my hot chocolate...Saludos<BR> Doug Dawn<BR> Mexico<BR> <BR> En un mensaje con fecha 12/15/2003 10:17:15 PM Mexico Standard Time, j.divel= biss_at_att.net escribe:<BR> <BR> <BLOCKQUOTE TYPE=3DCITE style=3D"BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT= : 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"><BR> <BR> To Rob, Bob, Adam, and others:<BR> <BR> Recent finds from the Nevada dry lakes were grouped in a small area within a= <BR> dry lake. The finding of three apparent pieces from same fall created a <BR> description by Adam that these finds might constitute a new strewnfield. <BR= > <BR> Questions/observations in regards to desert strewnfields.<BR> <BR> 1. Obvious groupings of fallen masses would make the likelihood of the area=20= <BR> being a meteorite stewnfield. Do multiple finds in desert locale usually get= <BR> described as a stewnfield?<BR> <BR> 2. Does the fact that many rocks get moved around in these environments take= <BR> the strewnfield idea down a notch with rocks being scattered?...or does thei= r <BR> proximity within the bounds of normal surface movements qualify them to be <= BR> still within the original strewnfield? <BR> <BR> 3. Is the idea of stating a location has a new strewnfield more about this <= BR> location being a new place to find more than one meteorite of the same <BR> apparent fall?...and not so much about the actual fall characteristics?<BR> <BR> I guess I'm just curious about the use of word strewnfield in this case?<BR> <BR> Yearning to be set straight,<BR> <BR> John<BR> <BR> <BR> </BLOCKQUOTE><BR> <BR> </FONT></HTML> --part1_40.38882ffd.2d0fe8ea_boundary-- Received on Mon 15 Dec 2003 11:49:46 PM PST |
 StumbleUpon del.icio.us reddit Yahoo MyWeb
|