[meteorite-list] Introducing Thumb Butte

[Wayne Holmes]

Congratulations to Todd Parker on his new classification Thumb Butte.

One nicely Oriented 104 g specimen H3.8 Chondrite. Todd found this specimen 
while hunting in the Bullhead/Laughlin area in Mar, 2008. This is the first 
of Todds 4 new cold finds to be classified.

Check out the pictures on my website (first page, scroll down).

http://www.meteoritesrock.com/index.html





Thumb Butte                          35º 10.196´N 114° 27.351´ W

     Mojave County, Arizona, USA

     Find: 1 March 2008

     Ordinary chondrite (H3.8)

History: Mr. Todd Parker found a 104 g stone on a small, alluvium-covered 
flat just west of Thumb Butte and 4 miles east of Bullhead City, Mojave Co., 
Arizona.

Physical characteristics: The single stone is mostly covered by moderately 
weathered reddish-brown fusion crust.

Petrography (T. Bunch and J. Wittke, NAU):  Chondrules have sharp outlines 
with a mean diameter of ~0.4 mm. Matrix is slightly recrystallzed with some 
remnant calcic glass. Chondrule mesostasis is clear to turbid and several 
chondrules are armored with metal and minor FeS. Contains olivine, 
orthopyroxene, kamacite, FeS, taenite, merrillite, Cl-apatite, chromite and 
a trace of plagioclase. Fresh interior with reddish staining, weathering 
grade is W1. Shock level is S2.

Mineral compositions: Olivine, Fa17.3 - 24; orthopyroxene, Fs15.7 - 19.1Wo 
1.5 - 2.3; taenite Ni = 41.2 wt%; chromite cr# = 86.

Classification: Ordinary chondrite (H3.8).

Type specimen: 20 g are on deposit at NAU. Mr. Todd Parker holds the main 
mass.