Fountain Hills

Maricopa County, Arizona, USA

Found 10/05/2002

Carbonaceous chondrite (Bencubbin-like meteorite)

A single stone weighing 60 g was found by a hiker on a desert trail near his home in Fountain Hills, AZ. Classification and analysis (D. Lauretta, A. R. La Blue, M. Killgore): The stone is a CB carbonaceous chondrite, no obvious shock features, weathering grade W1. The meteorite contains abundant, large (diameter up to 4.3 mm), volatile-depleted, barred olivine, porphyritic, and granularchondrules, no fine-grained matrix, and ~25% modal abundance of metal, lower than for other Bencubbin-like meteorites. Metal occurs almost exclusively outside of chondrules. Olivine composition is Fo96-98; low-Ca pyroxene composition is En96, Fe/Mn = 23, 1.7-1.9 wt% CaO; plagioclase is An99, 1.0 wt% MgO, 0.4 wt% FeO. Metal composition is 6.3-6.8 wt% Ni, 0.17-0.36 wt% Co, single grains are unzoned. No sulfides have been found. Oxygen isotopic composition: δ¹⁷O = -1.45 ‰, δ¹⁸O = +1.28 ‰.  Nitrogen isotopic composition: δ¹⁵N = +48 permil; see Lauretta et al. (2004), Blue et al., (2004). Type specimen: 12 g, Lunar and Planetary Laboratory, University of Arizona. Main mass: Southwest Meteorite Laboratory.