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Golden Gate Mountain
Basic information Name: Golden Gate Mountain
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: No
Year found: 2011
Country: United States
Mass:help 16.7 g
Meteoritical Bulletin:  MB 109  (2020)  H4
Recommended:  H4    [explanation]

This is 1 of 6474 approved meteorites (plus 2 unapproved names) classified as H4.   [show all]
Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 18 Jul 2020
Writeup from MB 109:

Golden Gate Mountain        32°08.999’N, 111°06.817’W

Arizona, USA

Find: 2011 May 1

Classification: Ordinary chondrite (H4)

History: Ingrid "Twink" Monrad found the meteorite on May 1, 2011, while she was meteorite hunting in the area where the Cat Mountain meteorite was found. The stone was found on top of the sand in a little dry streambed and was attracted to a magnet.

Physical characteristics: The 16.7 g complete stone is approximately 1.5 × 2.5 × 1.25 cm. It exhibits patchy, remnant fusion crust along with desert varnish in some places. The exposed meteorite displays a caramel color that is in contrast to the black and brown-stained interior cut face. Deep fractures penetrate the entire rock, some containing thin deposits of caliche. Numerous well-delineated chondrules are visible in the hand specimen.

Petrography: (K. Domanik and D. Hill, UAz) Microprobe examination of a polished mount shows numerous distinct, round to irregularly shaped chondrules that range from 50 to 1300 μm in size. Most chondrules are less than 100 μm in diameter. POP, PO, and PP chondrules predominate with a few RP and BO also present. 10 to 50 μm plagioclase patches occur almost exclusively within chondrules and typically contain abundant, small, quench crystals of clinopyroxene. The matrix consists of smaller chondrule fragments. Numerous veins and grains of highly oxidized (weathered) metal and troilite form complex networks. Minor amounts of chromite, merrillite, and chlorapatite are also present.

Geochemistry: Mineral compositions and geochemistry: (K. Domanik, UAz) EMPA: Olivine Fa18.1±0.2, Fe/Mn=36.1±2.1, (N=57); low-Ca pyroxene Fs16.0±0.2Wo1.1±0.4, Fe/Mn=22.4±3.1, (N=31); plagioclase An10.9±4.7Ab83.8±3.5 Or5.3±1.4, (N=6); kamacite Fe=92.9±0.4, Ni=6.5±0.1, Co=0.66±-0.04 (all in wt%), (N=6).

Classification: H4 (severe weathering)

Specimens: 13 g main mass, Ingrid "Twink" Monrad; 3.7 g UAz

Data from:
  Table 0
  Line 0:
Origin or pseudonym:dry streambed
Date:2011 May 1
Mass (g):16.7
Weathering grade:W3
Fayalite (mol%):18.1±0.2 (N=57)
Ferrosilite (mol%):16.0±0.2 (N=31)
Wollastonite (mol%):1.1±0.4 (N=31)
Classifier:D. Hill and K. Domanik, UAz
Type spec mass (g):3.7
Type spec location:UAz
Main mass:Ingrid "Twink" Monrad
Finder:Ingrid "Twink" Monrad
Comments:Field name was "Trash Flat". Not paired with other meteorites found nearby.; submitted by Dolores Hill
   and collections
UAz: Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd., Tucson, AZ 85721, United States (institutional address; updated 14 Jan 2012)
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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United States
     Recommended::   (32° 9' 0"N, 111° 6' 49"W)

     This is 1 of 179 approved meteorites from Arizona, United States (plus 1 impact crater)
     This is 1 of 1924 approved meteorites from United States (plus 867 unapproved names) (plus 28 impact craters)
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