Reporting Mineralogy And Chemistry of Kamargaon Meteorite, Assam, NE IndiaOPEN ACCESS
D. Majumdar, P.V. SunderRaju, T.K. Goswami, Md. Arif, D. S. Sarma
IOSR Journal of Applied Geology and Geophysics (IOSR-JAGG)
e-ISSN: 2321–0990, p-ISSN: 2321–0982.Volume 5, Issue 5 Ver. II (Sep. – Oct. 2017), PP 52-57
“We report here the composition and mineralogy of a meteorite, fell in Mahuramukh area near Kamargaon Town (93o46′ E, 26o39’N;) of Golaghat District, Assam on November 13, 2015 at 12:00 hrs IST, weighing about 12.095 Kg, registered as KomarGaon Meteorite and reported in the Meteoritical Bulletin No. 104, 2016; classed as ordinary L6 meteorite. The meteorite is covered with encrustations of varied colourfusion crusts, thickness and occasional regmaglypts in its outer facewith radiating shock veins. The inner face is light greyish white studded with brown native metal. Thin section petrography, ore petrography and chemical studies
were attempted using-state of the art analytical techniques such as EDXRF and SEM with EDS attachment. The chemical analyses were carried out on a representative piece of the meteorite sample. Mineralogically, the composition of meteorite is olivine, orthopyroxene, plagioclase and opaques. The ore petrographic study
revealed opaque phases – consisting of pyrite, troilite, kamacite, taenite and millerite with minor amounts of magnetite. Olivine exhibits shock impact features of weaker to moderate intensity (S3 and S4), marked by development of planar fractures, encrusted with a mosaic of olivine and occasional occurrence of melt veins.
Chemically, the meteorite contains 21.99 %Fe2O3, and 20.25 % MgO; 35.97 % SiO2; 4.02% Al2O3and Ni is about 0.32%. Due to the presence of merrillite and schreibersite, the P2O5content reads up to 735.719 ppm. SEM study reveals presence of Chondrules of chromite bearing magnetite, pyrite, Fe-Ni metals with