Kamargaon        26°37’56.9884"N, 93°46’11.5115"E

Assam, India

Confirmed fall: 13 Nov 2015

Classification: Ordinary chondrite (L6)

History: On November 13, 2015, at 12:00 pm local time, a meteorite fell near the town of Kamargaon in the Golaghat district of Assam, India. The villagers saw the meteorite falling from the clear sky on a bright sunny day followed by 30 to 40 s of sonic booms. A 12.095 kg mass impacted in a freshly plowed field forming a 45 cm diameter by 90 cm deep hole. The superintendent of police for the Golaghat district subsequently procured the meteorite. The fall was reported in the November 14 issue of the local newspaper, Dainik Janambhumi. Details of the fall are described by Goswami et al. (2016). The meteorite was broken into four pieces and three pieces distributed as follows: 2.668 kg to the Department of Applied Geology, DibrU, ~ 2kg to the Department of Physics, Assam University, and 2.15 kg to the Jorhat Science Center and Planetarium. Goswami, T.K., Ray, D., Sarmah, R.K., Goswami, U., Bhattacharyya, P., Majumdar, D., Bezbaruah, D. and Borgohain, P. (2016) Komargaon, Assam (India) witnessed a new meteorite fall. Planex, 6 (1), 10-11.

Physical characteristics: (T.K. Goswami, DibrU) Single fusion-crusted blocky stone showing a few broad regmaglypts. Sawn surface is light greyish white with even distribution of small metal and sulfide grains and a few recognizable chondrules, one to 8 mm. Stone crisscrossed by a few shock veins. The hammered stone broke along one of the shock veins, which shows a well-developed slickenside surface. Fusion crust to 1 mm thick.

Petrography: (L. Garvie, ASU) A polished microprobe section shows dominantly coarse-grained recrystallized minerals, with few recognizable chondrules. Plagioclase, anhedral, abundant to 250 μm. Sparse chromite grains to 350 μm are anhedral with rounded outlines and heavily fractured. Troilite grains to 400 μm, single crystal and lacking shock lamellae. Metal grains to 0.5 mm, range from polycrystalline kamacite, to composite grains composed of polycrystalline kamacite, dark etched plessite and high Ni-metal. Kamacite lacks Neumann bands. Fine-grained melt pockets are present but rare. Scattered Ca-Cl and Ca-Mg-Na phosphates to 0.5 mm found.

Geochemistry: (L. Garvie, ASU) Olivine Fa_25.1±0.4, Fe/Mn=48.4±3.2 wt%, n=16. Low Ca pyroxene Fs_21.2±0.2Wo_1.4±0.2, Fe/Mn=30.0±1.8 wt%, n=8. High Ca pyroxene Fs_8.4±0.3Wo_44.5±0.4, n=3. Feldspar An_9.4±0.4Or_6.7±0.2, n=8.

Classification: Ordinary chondrite, L6, S3, W0

Specimens: 23.4 g and one polished mount at ASU.