San Juan de Ocotán        20°42’42.1"N, 103°27’22.3"W

Jalisco, Mexico

Confirmed fall: 2007 Sept 22

Classification: Ordinary chondrite (L5)

History: On the night of 22 September 2007, Mr. Saldaña was woken around 3 am by a crashing sound at the side of his house. He went out to investigate and found a black rock at the foot of a brick wall in the courtyard of his house: the stone was reportedly warm to the touch. The rock had passed through a blue tarpaulin and thick plastic sheeting. For four years, Mr. Saldaña used the stone to prop open a door. However, after watching a television show on meteorites in early 2011, he realized the stone might be a meteorite and contacted Michael Farmer, who traveled to Guadalajara to purchase the stone and visit the fall site.

Physical characteristics: Complete 1365 g fusion-crusted stone, smooth, with a few scattered regmaglypts. Slightly flattened stone, with the largest face of 12 × 10 cm. Exterior shows a few minor rust spots and one corner is chipped and shows adhering blue material, presumably from the blue tarpaulin. Sawn surface dominantly mottled white and light grey exhibiting distinct chondrules separated by thin dark matrix. Chondrules up to 3 mm. Metal and troilite typically <1 mm, though one slice has a troilite/metal vein 3 cm long and up to 3 mm wide.

Petrography: (L. Garvie, ASU) Thin section dominated by sharply defined chondrules and chondrules fragments. Chondrule types include BO, RP, PO, and POP. Also a large compound PP chondrule containing two BO chondrules. Many of the chondrules have troilite/metal rims. Chromite grains scattered and <100 μm. Most metal has a holly-leaf-shaped outline. Metal is typically polycrystalline with a few grains showing dark plessitic etch, or tetrataenite rims with cores of vermiform plessite. Troilite polycrystalline and lacking shock lamellae. The troilite/metal vein consists of polycrystalline troilite (grain size 20 to 200 μm) surround by polycrystalline kamacite. Copper rare, occurring as <50 μm grains in troilite and at the troilite/metal boundaries. A few scattered Ca-Cl-rich and Na-Mg-Ca-rich phosphates to 200 μm found. Feldspar fine grained and difficult to recognize in the thin section. Olivine shows mosaicism and PDFs. Rare melt pockets found associated with the large troilite/metal vein.

Geochemistry: (L. Garvie, ASU) Olivine, Fa_24.2±0.5, Fe/Mn=46.4±3.3, n=18; low Ca pyroxene, Fs_20.7±0.9Wo_1.2±0.5, n=12. Only one high Ca pyroxene grain found, Fs_13.0Wo_30.4, Fe/Mn18.7.

Classification: L5, S4, W0

Specimens: 51.2 g and two thin sections at ASU.