[meteorite-list] Carancas or Titicaca? More data and a thin section of the stone

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Wed, 3 Oct 2007 13:44:58 -0500
Message-ID: <03ac01c805ed$80d4b1f0$b92ee146_at_ATARIENGINE>

Hi, Jeff, List

    I used the word "convention" in the sense that it
is "conventional" to do so, as most meteorites carry
the name of a human settlement of some kind. Technically,
it's the nearest "place name" that is unambiguously
locatable that is required.

http://www.meteoriticalsociety.org/bulletin/nc-guidelines.htm
    "3.1 Geographic features. A new meteorite shall be
named after a nearby geographical locality. Every effort
should be made to avoid unnecessary duplication or ambiguity,
and to select a permanent feature such as a town, village, river,
bay, cape, mountain or island which appears on widely used
maps and is sufficiently close to the recovery site to convey
meaningful locality information. In sparsely populated areas
with few place names, less permanent features such as ranches
or stations or, in extreme cases, local unofficial names of
distinctive quality may be used, provided the latitude and
longitude of the recovery site are well determined. The names
of large geographic features such as continents, countries,
provinces, states, and large counties should be avoided if
names that are more specific are available, except as specified
in ?3.3 and ?3.4. In general, the selected feature should be the
closest such feature to the site of the recovery. If, for example,
the name of the nearest town is already used, the meteorite should
not be named for the next nearest town. In such a case, a different
geographic feature (e.g., a stream) should be selected, if available
(if not, ?3.3 applies)."

    However, the village of Carancas is such a feature and
appears to be much closer to the crater than Lake Titicaca.
Randall Gregory says the crater is virtually on the banks
of the Lake, but it doesn't look that way on these maps.

    Maps of the locale can be found at this site:
http://www.earthfiles.com/news.php?ID=1321&category=Science

    The site also contains the full text of the INGEMMET initial
report (but NOT all the pictures) which contains interesting data.
There is an interview with Jose Machero, one of the authors of
the INGEMMET report (in which he says that the water table there
is one meter below grade).

The full INGEMMET report, with more thin section photos than
the above reference, including polarized views, can also be found at:
http://www.ingemmet.gob.pe/

Go over to the right and click on the Carancas link.

    Some quotes from that report:

Impact location
Country Peru
Region Puno
Province Chucuito
District Desaguadero
Community Carancas
Coordinates Lat: 16?39'52"S Long: 69?02'38"W
Elev: 3 824 m a.s.l.

General description of the phenomenon
(Only anecdotic information based upon witnesses' declarations)
Apparent displacement azimuth of the object: towards N030?E.
The object was observed since it was at about 1 000 m from the earth
surface.
The object presented a strongly luminous head (white light) and a white
smoky queue.
No other objects were observed to fall after the main body.
There was a strong explosion that was felt up to Desaguadero city
20 km from the impact site.
Some window glasses of the Local Health Center (at 1 km
from the site) were broken.
The explosion "sound" lasts about 15 minutes (!)
After the impact, boiling water was seen in the crater,
and a smoke column was formed that lasts for several minutes.
A "sulfurous" smell was reported there.

General description of effects on ground

The impact created a crater when collided with the soft
ground (reddish brown soil). The crater is composed
by a hole and an ejecta rim. The central hole became a
pond, by infill with groundwater that crops out after the
impact (figure 2). The following table gives the diameters
and other measures of the geoform.

N to S -- Pond 7.4 m -- Rim 13.3 m
E to W -- Pond 7.8 m -- Rim 13.8 m

The maximum rim height was 1 m above the original soil
level, and was seen in the northern border. The photo of
figure 2 is looking northward. Dispersal ejecta made by
brown soil with grey patina (meteorite powder), up to 5 cm
in diameter were found at 200 m from the impact point.

Three days after the fall, water in the pond was 1 m below
the original soil level. It presented turbid brown aspect, with
pH = 7.8, temperature 17.9?C, conductivity > 4000 milisiems,
and total suspended solids > 2000 ppm. (Measurements by
Prof. Mario Soto, Univ. of Altiplano, Puno).

Composition

Thin and polished sections were prepared for petro-mineralogic
determinations under optical microscope. The results revealed
chondritic texture and a mineral composition including:

Pyroxene 1 40%
Olivine 20%
Feldspar 10%
Pyroxene 2 10%

Opaque minerals total about 20% and include:

Kamacite 15%
Troilite 5%
Cromite traces
Native Cu traces


Sterling K. Webb
--------------------------------------------------------------------------
----- Original Message -----
From: "Jeff Grossman" <jgrossman at usgs.gov>
To: "Meteorite List" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, October 03, 2007 5:13 AM
Subject: Re: [meteorite-list] Carnacas smoke-trail photos


There is no such naming convention.

Jeff

At 01:03 AM 10/3/2007, Sterling K. Webb wrote:
>The name of the village closest to the
>crater site is CARANCAS, not Carnacas.
>Under the naming convention, the nearest
>named human settlement would end up
>as the name of the meteorite when all the
>dust settles, no?
>
>Let's all practice: CA - RAN - CAS.
>
>
>Sterling K. Webb
Received on Wed 03 Oct 2007 02:44:58 PM PDT