by Robert Verish

Met Soc 2002 Meeting – Coming to L.A.!

The focus of the meteorite community, this month, will be on the 65th Annual Meeting of the Meteoritical Society.  And the meeting place, this year, will be in Los Angeles (primarily at UCLA).  Obviously, this is going to be the “Main Event” for all of us meteorite aficionados here in Southern California. In fact, this article will have to be kept short this month, because I still have to help my colleagues prepare for our presentation.  (The topic is related to dry lakes, of course;-) No doubt, I’ll report the topic of our presentation in one of my future articles.  Something with a title like, “Bob’s Findings goes to the Met. Soc. Meeting”!  

 Don’t get the wrong idea.  This conference won’t be dry, technical lectures all day long.  There will be some fun things to do at this meeting. There will be various tours and field trips. I’m somewhat surprised that no field trips have been scheduled to visit our local dry lakes.  But a wine-tasting tour of some of our local vineyards, as well as a field trip to some of our earthquake-prone faults, is more in line with what visitors want to see when they visit Southern California.  And then, before the attendees return home from this week-long meeting, there will be an opportunity to join an excursion to the Grand Canyon and Meteor Crater conducted by staff from the University of Arizona.

 For more details regarding all the different events, here is a link to the UCLA 2002 Meeting web site:

 http://www.lpi.usra.edu/meetings/metsoc2002/

 This web site also gives you access to all of the Abstracts for all of the presentations that will be given at this conference.

Here is a link to the Program schedule:

http://www.lpi.usra.edu/meetings/metsoc2002/pdf/program.pdf

 It will be interesting to see how the LA media and local press will report on the presentations from this meeting.  But although everyone has their favorite topics, here are some of the sessions that I am looking forward to attending:

 THE TIMING OF MAGNETITE FORMATION IN ALH84001

CARBONATE GLOBULES. A. H. Treiman. Lunar & Planetary Institute, 3600 Bay Area Blvd., Houston, TX 77058-1113 USA.<treiman@lpi.usra.edu>. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5057.pdf

 COLORADO METEORITES UPDATED.  J. A. Murphy, Curator of Geology, Denver Museum of Nature and Science, 2001 Colorado Blvd., Denver, CO 80205-5798. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5165.pdf

 TERRESTRIAL AGES OF SOME METEORITES FROM OMAN. A. J. T. Jull 1 , J. Koblitz 2 , B. Hofmann 3 , I. A. Franchi 4 , L. R. McHargue 1 and A. Shahab 1 , 1 NSF Arizona AMS Laboratory, Univ. of Arizona, Tucson, AZ 85721, USA, 2 Im Neuen Felde 16, D-28870 Fischerhude, Germany, 3 Natural History Museum Bern, Bernastr. 15, CH-3012 Bern, Switzerland, 4. Planetary Sciences Research Institute, Open University, Milton Keynes MK7 6AA England. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5044.pdf

 THE EFFECT OF ACCRETION ON ASTEROID THERMAL HISTORY: HEBE, THE MOVIE. A. Ghosh 1 , S. J. Weiden-schilling 2 and H. Y. McSween Jr.1 , 1 Planetary Geoscience Institute and Dept. of Geological Sciences, University of Tennessee, Knoxville, TN 37996-1410, USA. 2 Planetary Science Institute, 620 North Sixth Avenue, Tucson, AZ 85705-8331, USA. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5191.pdf 

DENSITIES AND POROSITIES OF SOME ORDINARY CHONDRITE METEORITES. S. L. Wilkison 1 , M. S. Robinson 1 , J. E. McCamant 2 and D. T. Britt 3 , 1 Department of Geological Sciences, Northwestern University, Evanston, IL 60208, 2 Williams College, Williamstown, MA 01267, 3 Department of Geological Sciences, University of Tennessee, Knoxville, TN 37996. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5278.pdf

We measured the densities and porosities of 38 pieces of 30 samples of ordinary chondrites (falls). Preliminary results indicate that the porosities of our samples range from 0-21%. Consistent with previous work [1,2,4], we found no correlation between porosity and metamorphic grade or between porosity and mass of the sample.

 MINERALOGY AND MICROTEXTURES OF MELT POCKETS IN THE LOS ANGELES BASALTIC SHERGOTTITE. E. L. Walton and J. G. Spray, Planetary and Space Science Centre, Department of Geology, University of New Brunswick, 2 Bailey Drive, Fredericton, NB E3B 5A3, Canada. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5247.pdf

 BULK COMPOSITION OF TAFASSASSET – EVIDENCE FOR INCIPIENT MELTING. J. Zipfel 1 , H. Palme 2 , B. Spettel 1 , and T. Schönbeck 2 . 1 Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany, 2 Universtät zu Köln, Zülpicherstr. 49b, 50674 Köln, Germany. http://www.lpi.usra.edu/meetings/metsoc2002/pdf/5092.pdf

 

All of the abstracts listed in the Program, as well as the final version of the Meteoritical Bulletin, will be published in the separate “Supplement Volume” to the July or August issue of the Meteoritical Society journal, Meteoritics and Planetary Sciences (MAPS).  This May be the last year that this “convenience” will appear in MAPS.  (More about this later in this article.) 

Recently, Rob Matson forward to me the following Abstract from the upcoming August 2002 issue of MAPS: 

The Dar al Gani Meteorite Field (Libyan Sahara): Geological Setting, Pairing of Meteorites, and Recovery Density
 
J. Schlüter*, L. Schultz, F. Thiedig, B.O. Al-Mahdi and A.E. Abu Aghreb  

*Correspondence author's address:  Mineralogical Museum, University of Hamburg, Grindelallee, D-20146 Hamburg, Germany;

e-mail address: minmushh@public.uni-hamburg.de

 

Abstract-

“1238 Libyan meteorites have been reported up until July 2001. Most were found in two areas called Dar al Gani (DaG) and Hamadah al Hamra (HaH).

DaG is located on a plateau of marine carbonate rocks with marly components. 869 meteorites between 6 g and 95 kg totalling 687 kg have been found here but the calculated mean recovery density is comparatively low with one meteorite on 6.5 km2.

 

DaG is a perfect site for the recognition and preservation of meteorites. The existence of meteorites is the result of a combination of specific geological and geomorphological conditions: there is an bright-colored, old limestone plateau (< 2 Ma), under arid weather conditions over long periods of time, with rapid elimination of surface water if present and low erosion rates. The preservation of meteorites is guaranteed through the absence of quartz-sand on the plateau, strongly reducing wind erosion and a basic environment emerging from the carbonate ground retards rusting of metallic meteorite components. A supposed soil cover during pluvial times has probably protected older meteorites and led to a concentration of meteorites of different periods. An evaluation of DaG meteorites suggests the existence of at least 26 strewnfields and 26 meteorite pairs reducing the number of falls to at most 534. Shock and weathering grades as a tool for the recognition of pairings turned out to be problematic, as several strewnfields showed paired meteorites which had been classified to different shock and weathering grades. “

----------------------------------

 

The following are two quotes that were of particular interest to Rob and myself: 

"the calculated mean recovery density is comparatively low with one meteorite on 6.5 km^2."

This number caught Rob’s attention, since he has been compiling all of the Mojave Desert Meteorite-Recovery Program finds and calculating his own “mean recovery density”.  According to Rob, the Libyan Sahara number is quite a bit lower than the recovery density for Southern California/Nevada dry lakes (which is closer to one meteorite per 2.3 km^2).  I pointed out to Rob that this apparent disparity would eventually balance out should our Meteorite-Recovery Team be given the opportunity to search the DaG plateau!  ;-)

 

The other phrase of interest:

 "Shock and weathering grades as a tool for the recognition of pairings turned out to be problematic, as several strewn fields showed paired meteorites which had been classified to different shock and weathering grades."

 I rolled my eyes and said to Rob, “You think that’s ‘problematic’!  How about the Gold Basin strewn field that had different meteorites that had been classified to different PETROLOGIC GRADE, yet they are still “deemed” paired!?  What’s up wif dat?”

 

* And now, in regards to where future Annual Meeting Abstracts, as well as the Meteoritical Bulletin, will be published, I think it best that I quote directly from the Council Meeting minutes:

 

Minutes of the meeting of the Council of the Meteoritical Society  March 10, 2002 at the Lunar and Planetary Institute, Houston, TX  http://www.uark.edu/campus-resources/metsoc/min0102.htm

 

++++snip!++++

 “6. Publications Committee report

        The chair of the new Publications Committee, Hap McSween, presented his report dated December 10, 2001 (Appendix 7).

 

a) MAPS Supplement.  The Committee was asked to address a suggestion made by the MAPS Editor and Associate Editors that the Meteoritical Bulletin and other non-refereed materials should be published in a new house journal rather than in the MAPS Supplement.  The Committee first determined that the abstracts have little or no effect on the journal’s impact factor.  In order to ascertain whether the presence of the Meteoritical Bulletin is perceived to have a negative effect on the journal’s prestige, the committee polled a subset of members;

55 responded as follows:

 

Is the present system (inclusion of abstracts and other non-peer reviewed materials in a MAPS Supplement) harmful to MAPS prestige as a scientific journal?  Responses:  YES (14%), NO (86%)

 

Is the present system beneficial to METSOC members by making abstracts and other materials more readily available?  Response:  YES (98%), No (2%)

        Based on these responses and the unsolicited comments provided by many respondents, a majority of the Committee concluded that little, if any harm to the prestige of the journal results from publishing abstracts as a Supplement.  The Committee saw no compelling need for changing the way in which abstracts are presently published, and thus recommended that the abstract Supplement to MAPS be retained.  The Committee would address the Meteoritical Bulletin in a future report after it had obtained advice and information from the appropriate Editors.

 

b) Abstracts.  The Committee then addressed whether the production of abstracts could be made less time-consuming and costly.  The Editor and Associate Editors had recommended that limits be placed on the size of abstracts and that print-only abstracts should not be accepted. 

++++snip!++++

Motion: The Council accepts the recommendations of the Publications Committee concerning the publication of the abstracts in the Supplement to MAPS.

Proposed Scott, seconded Drake. Passed unanimously.” (unquote)

 

What all this means is that,

a)      there will be a Supplement Volume to the MAPS (for the foreseeable future), and

b)      there will be a “Meteoritical Bulletin” (although it might not continue to appear in this Volume), but

c)      there will NOT be any “Print-Only” abstracts accepted for publication in this Supplement Volume.

 

If you would like to see some recent examples of “Print-Only” abstracts, and what will (soon) NOT be appearing in the “Supplement Volume” of MAPS, you can go to these URLs:

 http://www.lpi.usra.edu/meetings/metsoc2001/pdf/sess54.pdf

 http://www.lpi.usra.edu/meetings/lpsc2001/pdf/sess84.pdf

 http://www.lpi.usra.edu/meetings/metsoc2002/pdf/sess28.pdf

Okay!  Now you be the judge. 

And regarding the question, “Where should the Meteoritical Bulletin be published?”, Maybe I should conduct my own poll:

 Is the present system (of including the Meteoritical Bulletin in a MAPS Supplement) a tradition that should be continued? 

Respondents please answer:  YES (__%), or NO (__%)

 Considering that so many of the abstracts that are essentially “announcements of a major new find” tend to be relegated to the “Print-Only” session, Maybe these should be combined with the Meteoritical Bulletin to form a new, all-inclusive journal that is dedicated to fully documenting new meteorites.  This May solve the loss of “recovery information” that has resulted from listing new meteorites into “Tables”. In addition, the updating of the Catalogue of Meteorites can be facilitated.  It can reference the information in this new journal.

Should the Meteoritical Bulletin be made into it’s own, expanded, on-line/published journal so that there is a return to fully documenting new meteorites with adequate space for describing “Fall/Find Recovery Information”? 

Respondents please answer:  YES (__%), or NO (__%)


Unfortunately, this web page is not set up to conduct “polls”, but feel free to contact me with your responses.  Or better yet, contact the editors of MAPS and the Meteoritical Bulletin directly with your suggestions.  Both the Meteoritical Society Council and the Nomenclature Committee will be holding meetings at the 65th Annual Meeting in LA, and these very topics will be discussed.

For more information, please contact me by email: Bolide*chaser