[meteorite-list] The Perils of Type Collecting - A Guide

From: Greg Stanley <stanleygregr_at_meteoritecentral.com>
Date: Wed, 3 Mar 2010 16:29:00 -0800
Message-ID: <SNT117-W385509C071AA7B25593DA5D2390_at_phx.gbl>

Murchison is a CM2

Greg S.

----------------------------------------
> Date: Wed, 3 Mar 2010 19:12:20 -0500
> From: cdtucson at cox.net
> To: meteorite-list at meteoritecentral.com; damoclid at yahoo.com; meteoritemike at gmail.com
> Subject: Re: [meteorite-list] The Perils of Type Collecting - A Guide
>
> Good list,
> missing is the division between
> CBa Buencubbin
> CBb HAH 237
> CK3
> and Tagish lake is not ungrouped but I think is a C2.
> --
> Carl or Debbie Esparza
> Meteoritemax
>
>
> ---- Richard Kowalski wrote:
>> Thanks a lot Mike.
>>
>> I thought I had pretty much completed my type set a few months ago, but now I see that I'm missed a few gradations that maybe I should pay attention to.
>>
>> I think, for budgetary and sanity sake, I'll have to be selective in how fine my divisions are than to try to get every sub-type you mention!
>>
>> --
>> Richard Kowalski
>> Full Moon Photography
>> IMCA #1081
>>
>>
>> --- On Wed, 3/3/10, Galactic Stone & Ironworks wrote:
>>
>>> From: Galactic Stone & Ironworks
>>> Subject: [meteorite-list] The Perils of Type Collecting - A Guide
>>> To: "Meteorite List"
>>> Date: Wednesday, March 3, 2010, 4:18 PM
>>> Greetings Listees and fellow
>>> collectors,
>>>
>>> To the veteran collector, there will be little of interest
>>> in this
>>> post. This post is directed at the silent newbie or
>>> beginner lurkers
>>> who are sorting through this List and trying to find their
>>> way around
>>> the world of collecting meteorites.
>>>
>>> Many new collectors often want one of each type of
>>> meteorite. Many
>>> veteran collectors abandon this pursuit because the task is
>>> quite
>>> daunting. So when you hear talk about
>>> "type collecting", or building
>>> a "type collection", what exactly does that mean? I
>>> hope the
>>> following brief article will answer those questions, or at
>>> least point
>>> the reader in the right general direction. Note, I
>>> gleaned much of
>>> this type information from David Weir's authoritative
>>> website
>>> "Meteorite Studies" and from the Meteoritical
>>> Bulletin. I do not
>>> claim that this list is 100% complete or without error, so
>>> if the
>>> reader spots an error or omission, please reply and correct
>>> it.
>>>
>>> -----
>>>
>>> The Perils of Type Collecting ........
>>>
>>> I started out collecting meteorites with a small sample of
>>> NWA 4293 -
>>> an ordinary high iron chondrite of the H6 type. It was
>>> about the size
>>> of a dog-food kibble and it looked like one. But I was
>>> instantly
>>> hooked, and I wanted to have one each of the different
>>> types of
>>> meteorite. This is known as "type collecting" or building a
>>> "type
>>> collection".
>>>
>>> The danger of type collecting (besides the damage to one's
>>> checking
>>> account) is that the various petrologic types are
>>> subdivided into
>>> various grades according to metamorphism.
>>>
>>> For example, take the H chondrite group that my NWA 4293
>>> sample belonged to.
>>>
>>> There are H3 chondrites, H4 chondrites, H5 chondrites, and
>>> H6
>>> chondrites. Did I really need one each of these subtypes?
>>> Well, it
>>> depends on how deep a collector wants to go into the rabbit
>>> hole.
>>> There are distinct differences between the various H types.
>>> The number
>>> attached to each is more than just a simple weathering
>>> grade or shock
>>> grade. It represents a progession in the H-chondrite family
>>> from least
>>> altered to most altered. H3 chondrites are loaded with
>>> chondrules, H4
>>> have some chondrules, H5 has few chondrules, and H6 has
>>> virtually no
>>> visible chondrules. A new grade of H7 has been added as
>>> well. So, a
>>> collector could simply have a single Hx chondrite and say
>>> that the
>>> H-chondrites are represented. Or, the collector could have
>>> one each of
>>> the different subtypes from 3 to 7.
>>>
>>> Another peril is the changing of nomenclature. For example,
>>> the
>>> K-subgroup of carbonaceous chondrites was only recognized
>>> and
>>> designated in 1990. Up until then, Karoonda was considered
>>> a CV4
>>> meteorite of the Vigarano family. Now Karoonda is
>>> recognized as
>>> distinctly different type of carbonaceous chondrite, so it
>>> was made
>>> into it's own group. Now we have CK4, CK5, and CK6
>>> meteorites - all
>>> represent a progression in metamorphism and have visible
>>> (and
>>> chemical) differences from other grades. There are standout
>>> members of
>>> each subgroup, so where does one draw the line? Should the
>>> collector
>>> acquire a sample of Karoonda and be done with it? Or should
>>> the
>>> collector go out and track down CK4, CK5 and CK6
>>> meteorites? Again, it
>>> depends on how extensive and exhaustive a collector wants
>>> to be with
>>> their type collection. Budget will also play a role as
>>> well, because
>>> an exhaustive type collection is a daunting project.
>>>
>>> Lastly, one must consider the ungrouped meteorites. These
>>> are oddball
>>> meteorites that do not neatly fit into the pre-existing
>>> meteorite
>>> types. There are ungrouped chondrites, ungrouped
>>> achondrites, and
>>> ungrouped irons. No type collection can overlook these
>>> meteorites
>>> because some of them are types unto themselves with unique
>>> qualities.
>>>
>>> For those who want to build a definitive and complete type
>>> collection,
>>> here is a list of every known type and subtype of
>>> meteorite. This list
>>> was culled from other sources, including David Weir's
>>> authoritative
>>> "Meteorite Studies" website linked at the end of this
>>> post.
>>>
>>> Carbonaceous Chondrites :
>>>
>>> CI (Ivuna)
>>> CM1 (Murchison)
>>> CM2 (subdivided into CM2.0 to CM2.6)
>>> CM3
>>> CO3 (Ornans) (subdivided into CO3.03 to CO3.7)
>>> CV (Vigarano) (also CV2 and CV3)
>>> CK (Karoonda) (CK4, CK5, CK6)
>>> CR (Renazzo) (CR1, CR2, CR3)
>>> CB (Bencubbin)
>>> CH
>>> CR ungrouped
>>> C4 ungrouped
>>> C ungrouped (Tagish Lake, others)
>>>
>>>
>>> Ordinary Chondrites :
>>>
>>> Rumuruti R3 (subdivided into R3.5-6 to R3.9)
>>> R4
>>> R5
>>> R6
>>>
>>> LL (subdivided into LL3.0 to LL3.9)
>>> LL4
>>> LL5
>>> LL5/6
>>> LL6
>>> LL6/7
>>> LL7
>>> LL impact melt
>>>
>>> LL transitional (L/LL3 to L/LL6)
>>> L (subdivided into L3.0 to L3.9)
>>> L4
>>> L5
>>> L6
>>> L6/7
>>> L7
>>> L impact melt
>>>
>>> H/L transitional (H/L3 to H/L6 IMB, H/L3.6 to H/L3-4)
>>> H (subdivided into H3.0 to H3.9)
>>> H4
>>> H5
>>> H6
>>> H7
>>> H impact melt
>>> ungrouped ordinary chondrites
>>>
>>>
>>> Enstatite Chondrites :
>>>
>>> EL (EL3 to EL7)
>>> EL impact melt
>>> EH/L
>>> EH (EH3 to EH7)
>>> EH impact melt
>>> ungrouped enstatite chondrites
>>>
>>> K (Kakangari)
>>>
>>> Meta-chondrites (M-CV, M-CR, M-H, M-LL)
>>>
>>>
>>> Primitive Chondrites :
>>>
>>> Acapulcoite
>>> Lodranite
>>> Winonaites
>>> ungrouped primitive chondrites
>>>
>>>
>>> Achondrites :
>>>
>>> Howardite (subdivided into fragmental breccia and regolith
>>> breccia)
>>> Eucrite (monomict and polymict with each having
>>> subclasses)
>>> Diogenite (monomict and polymict)
>>> Olivine Diogenite
>>> Dunite
>>> Ureilite (monomict and polymict)
>>>
>>>
>>> Martian achondrites :
>>>
>>> Shergottite
>>> Pyroxene-phyric basaltic shergottite
>>> Olivine-phyric basaltic shergottite
>>> Olivine-orthopyroxene-phyric basaltic shergottite
>>> Pyroxene-peridotitic (Wehrlitic) shergottite
>>> Lherzolitic shergottite
>>> Diabasic shergottite
>>>
>>> Nakhlite
>>> Chassignite
>>> Orthopyroxenite (ALH 84001)
>>>
>>>
>>> Lunar Achondrites :
>>>
>>> Feldspathic breccias
>>> Regolith breccia
>>> Fragmental breccia
>>> Impact melt breccia
>>> Granulitic breccia
>>> Mafic-rich
>>> Thorium-rich
>>> KREEP-rich
>>>
>>> Mingled Breccia
>>> Mare Basalt
>>>
>>>
>>> Other Achondrites :
>>>
>>> Angrites (Plutonic and Basaltic)
>>> Brachinite
>>> Aubrite
>>> ungrouped achondrites (Ibitira, Pasamonte, etc)
>>>
>>>
>>> Stony-Irons :
>>>
>>> Mesosiderites (1A,1B,2A,2B,2C,3A,3B,4A,4B)
>>> ungrouped mesosiderites
>>>
>>> Pallasites (Main Group, Eagle Station group, Pyroxene
>>> group)
>>> Pallasite-am (anomalous, PMG-am, PMG-as)
>>> ungrouped pallasites
>>>
>>>
>>> Iron meteorites :
>>>
>>> Note, iron meteorites are a can of worms. I will only focus
>>> on the
>>> main chemical groups, and not the various grouplets and
>>> sub-types of
>>> each main chemical group. Also note that many of
>>> these types include
>>> silicated varities. Listing all of the known
>>> sub-types of irons would
>>> require a LONG list resembling a flow-chart.
>>>
>>> IAB
>>> IC
>>> IIAB
>>> IIC
>>> IID
>>> IIE
>>> IIF
>>> IIG
>>> IIIAB
>>> IIIE
>>> IIIF
>>> IVA
>>> IVB
>>> ungrouped irons
>>>
>>> I think that is all of them - as currently recognized by
>>> the
>>> Meteoritical Society Nomenclature Committee. If anyone can
>>> think of
>>> some I missed, please add them to this list.
>>>
>>> David Weir's Meteorite Studies website - http://www.meteoritestudies.com/
>>>
>>> Best regards and happy collecting!
>>>
>>> MikeG
>>>
>>>
>>> --
>>> ------------------------------------------------------------
>>> Mike Gilmer - Galactic Stone & Ironworks Meteorites
>>> http://www.galactic-stone.com
>>> http://www.facebook.com/galacticstone
>>> ------------------------------------------------------------
>>> ______________________________________________
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>>>
>>
>>
>>
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Received on Wed 03 Mar 2010 07:29:00 PM PST