Jalangi        24°05’55’’N , 88°41’28’’E

West Bengal, India

Confirmed fall: 2012 Jul 08 (05:15 AM IST)

Classification: Ordinary chondrite (L5/6)

History: According to local observers, the meteorite came from the southwest, with repeated detonating and whizzing sound. The stone fell on soft soil in a jute field, making an impact pit of about six inches in diameter and eight inches in depth. From the recorded data, it appears that the meteorite fragmented at least two to three times before hitting the ground, indicating the existence of more pieces of the same meteorite. GSI officers searched the locality for additional fragments, but could not find any. It may be possible that some pieces were lost in the adjacent Jalangi or Ganges river. The meteorite was taken into the custody of the local police station within three hours of the fall. The District Magistrate and the Superintendent of the Police, Murshidabad district, West Bengal both were contacted by the Director, Central Petrological Laboratories (CPL), GSI, Central Headquarters, Kolkata-700016 to confirm the news about the meteorite fall. The State Government officers agreed to hand over the sample to GSI. Two officers from GSI, Dr. M. Moitra and Dr. S. Nandy, Senior Geologists, immediately rushed to the spot and collected the meteorite piece weighing about 2 kg from the State Government officers (BDO, Jalangi Block and OC, Jalangi Police Station) on 10 July 2012 (Source: Geological Survey of India, Meteorite Fall Near Jalangi, Murshidabad, W. Bengal on 08.07.2012., www.portal.gsi.gov.in/gsiImages/information/meteorite_fall_jalangi.pdf).

Physical characteristics: The meteorite is roughly pyramidal in shape, with a flat base and four complete surfaces (long axis ~ 11 cm), covered almost fully by thin black to brown colored fusion crust (thickness ~1-2 mm). The surfaces are smooth, well ablated, with traces of flow lines. Well-developed surface grooves and regmaglypts are observed. A few shallow regmaglypts, along with one slightly deep and compound variety, was noted on frontal surfaces. A number of well defined, visible chondrules and minute metallic specks were also recorded. Anastomosing thin opaque melt veins and veinlets were also observed.

Petrography: This meteorite is composed of olivine + orthopyroxene + feldspathic glass + Fe-Ni metals (kamacite and taenite) + troilite ± magnetite ± merrillite ± apatite. The chondrules are olivine and orthopyroxene, with the interstitial spaces (mesostasis) occupied by feldspathic glass ± pyroxene. The size of chondrules varies from 300-1000 μm (diameter). The shape of chondrules varies from near circular - elliptical to sub-elliptical and angular. Chondrules types are Barred Olivine (BO), Porphyritic Pyroxene (PP), Porphyritic Olivine (PO), Porphyritic Olivine Pyroxene (POP) and Granular Olivine (GO), and individual chondrule margins are moderately well delineated. Matrix is relatively fine grained and thoroughly recrystallized. Matrix:chondrules ~60:40. Matrix is brecciated in places. Fragments of olivine and orthopyroxene are enclosed within opaque melt veins (length >> width; maximum width of the vein ~1 mm). Numerous metal (Fe-Ni) droplets (micrometer to submicrometer scale) are confined within these melt veins / veinlets. The feldspathic melt glass (plagioclase composition) is relatively fine grained, patchy and dessiminated in the matrix. Rarely it also forms glassy chondrules (diameter ~400 μm).

Geochemistry: Olivine, Fa_24-27Fo_73-76; clinoenstatite, En_74.8-77Fs_21-23.4Wo_1-2; clinopyroxene (pigeonite), En₇₂FS19.3Wo_8.7; and feldspathic glass (albite to oligoclase), Ab_75-85An_9.4-21Or_3-8.6 with FeOT content <= 1.00 wt%). Kamacite contains Fe ~88-93% and Ni ~7-12%; taenite contains Fe ~45% and Ni ~55%.

Classification: Different textural variants of olivine and orthopyroxene exhibit near consistent mineral chemical compositional range (XMg) suggesting Jalangi is an equilibrated ordinary chondrite (L5-6).

Specimens: The District Magistrate and the Superintendent of the Police, Murshidabad district, West Bengal, India both were contacted by the Director, Central Petrological Laboratories (CPL), Geological Survey of India, Central Headquarters, Kolkata-700016 to confirm the news about the meteorite fall. The sample was handed over to GSI officers, Kolkata by the State Government officers of Murshidabad district, West Bengal [ Block Development Officer (BDO), Jalangi Block and Officer In-Charge (OC), Jalangi Police Station] on 10th July 2012. The sample was registered as ordinary chondrite on 17th July 2012 at NMR, GSI, Kolkata. (Source: Geological Survey of India, Meteorite Fall Near Jalangi, Murshidabad, W. Bengal on 08.07.2012., www.portal.gsi.gov.in/gsiImages/information/meteorite_fall_jalangi.pdf).