[meteorite-list] more putorana

From: Jeff Grossman <jgrossman_at_meteoritecentral.com>
Date: Thu Apr 22 09:54:10 2004
Message-ID: <5.1.0.14.2.20020225112434.0237f828_at_pop3.norton.antivirus>

Without digging into this, I have a paper by Finn Ulff-Mo/ller, "Native
iron bearing intrusions of the Hammers Dal Complex, North-west
Disko," Rapp. Gro/nlands geol. Unders. 81, 15-33 (1977). He says:

"The main part of the native iron in the rocks of the Hammers Dal Complex
is roughly divided into two major types: iron which forms cumulates in the
marginal dolerite [diabase] and iron spherules in the intermediate rock
characterized by columnar jointing.
    "In the pipes and the dyke-like intrusions the Fe cumulates form zones
of sickle-shaped cross-section. These opaque minerals, which are embedded
in a doleritic matrix sparsely disseminated with troilite, makeup 15-25
percent by volume of a cumulative zone. Accessory constituents are
ilmenite, ulvo"spinel, pentlandite and a copper-iron sulfide of which the
latter two exolved from the troilite...
    "Based on the detailed survey of the intrusions it appears that the
amount of iron concentrated in the Fe cumulates relative to the volume of
the particular intrusion is fairly constant -- about 0.5 percent by volume
corresponding to 1.1-1.3 percent by weight."

So there are very metal-rich zones in some Disko rocks, although overall
they don't have too much metal.

Finn later states that Fe metal in the spherules in the intermediate rock
makes up 2 wt% of the rock. I think that this is the lithology that Matt
and I have both seen, which doesn't appear to have much metal.

jeff

At 10:05 AM 2/25/2002, you wrote:
>I've seen the stuff from Disko and the metal is MUCH more sparse than
>Putorana. Plus the matrix is very grey and dull.
>Matt
>
>-----Original Message-----
>From: meteorite-list-admin_at_meteoritecentral.com
>[mailto:meteorite-list-admin_at_meteoritecentral.com]On Behalf Of Dave
>Harris
>Sent: Monday, February 25, 2002 2:50 AM
>To: metlist
>Subject: [meteorite-list] more putorana
>
>
>Hi there folks,
>Further to the Putorana thread... whilst it is said that this material is
>one of the best meteorwrongs around, I have never seen any of the other iron
>in basalt contenders (ie material from Disko Isl. &c.)
>Has anyone out there got any pics of the other iron in basalt from these
>other sources?
>I was just interested to see if they were similar in appearance.
>I could see that one of the arguments supporting Mr. Norton's hypothesis
>that the iron in Putorana was sourced from a plume from the core was the
>presence of Ni. Would not any iron derived from mantle rocks also have a
>%age of Ni in it?
>very best!
>dave
>
>--
>In gentle decay,
>dave
>
>IMCA #0092
>
>imca_0092_at_hotmail.com (for IMCA member contact)
>
>http://www.meteorites.ic24.net/index.html
>
>http://www.meteoritecollectors.org
>
>"I have a proof that x^n+y^n=z^n never has integer solutions for n>2.
>However, it won't fit into my signature file...."
>
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Dr. Jeffrey N. Grossman phone: (703) 648-6184
US Geological Survey fax: (703) 648-6383
954 National Center
Reston, VA 20192, USA
Received on Mon 25 Feb 2002 11:50:42 AM PST