Impact Melt Breccia
Item: 32.1 Dimensions: 70 x 62 x 7 mm Weight: 100.5 g
Provenance: University of New Mexico, Albuquerque
This specimen has a coarse matrix with chondrules up to 4 mm and a finely brecciated melt caused by cosmic impact. This slice shows both lithologies.
Partial/complete: Complete slice
Cube: ~15mm x 15mm x 15mm ≈ 15mm3

Chico

Country: USA
Region: New Mexico
Found: 1954
Group: Stone
Type: Ordinary Chondrite
Class: L6/LL
Total known weight: 104.8kg

Chico is an impact melt breccia. It has a coarse matrix with chondrules up to 4mm and a finely brecciated melt caused by cosmic impact. This slice shows both lithologies. A weathered stone of 231lb was found, the chondrules are up to 2 cm in diameter, L.LaPaz, Meteoritics, 1954, 1, p.182 (M.A.13-53). Analysis, B.Mason and H.B.Wiik, GCA, 1964, 28, p.533. Listed, K.Keil, Fortschr. Min., 1960, 38, p.215. Further analysis, 19.06% total Fe, V.Y.Kharitonova, Meteoritika, 1969, 29, p.91. Classification and analysis, shocked and weathered, olivine Fa24.2, D.E.Lange and K.Keil, Meteoritics, 1976, 11, p.315 (abs.). Mineral analysis of host (olivine Fa25.1) and impact melt rock (olivine Fa25.2), E.R.D.Scott et al., LPSC, 1986, 17, p.785 (abs.). Ar-Ar age, cosmogenic radionuclides and noble gases, D.D.Bogard et al., LPSC, 1990, 21, p.103 (abs.). Cosmogenic nuclides, irradiation history, D.H.Garrison et al., LPSC, 1991, 22, p.429. Ar isotopic data, D.H.Garrison et al., Meteoritics, 1991, 26, p.336 (abs.). Ar-Ar ages of shock-melted phases, D.H.Garrison and D.D.Bogard, LPSC, 1992, 23, p.397 (abs.). Petrographic shock classification, D.St