Dokachi meteorite, Munshiganj District, Dhaka Division, Bangladeshi

Regional Level Types
Dokachi meteorite	Meteorite Fall Location
Munshiganj District	District
Dhaka Division	Division
Bangladesh	Country

Ordinary chondrite, veined (H5)
Fell, 22 October 1903, 19 hrs; 3.84 kg

After the appearance of a fireball accompanied by detonations, a shower of over 100 stones fell. 24 stones were recovered, the largest with a mass of 1.571 kg. Most recovered stones were complete and usually covered with a largely intact and blackish fusion crust. A few grayish chondrules (PO, BO, RP) and grains of Fe-Ni metal and troilite are set within a grey and white matrix. Olivine (Fa19) and low Ca-orthopyroxene are characteristic of the H-chondrite geochemical group. Mineralogically, dominant olivine and low-Ca pyroxene are accompanied by minor troilite and Fe-Ni metal (kamacite, taenite). Accessory chromite, copper, and other minor opaques are also reported. Shock indicators include a number of veins and twinned prismatic Ca-poor clinopyroxene.

A Pb,Th:He age of 2.99 Ga and a cosmic-ray exposure age of 5.9 Ma are reported. The CRE age is similar to those of many other H5 chondrites, suggesting that as pre-terrestrial meteoroids some of the H5 meteorites were involved in the same collisions before eventual impact with the earth.

The H (relatively high in total iron) chondrites are the second largest group of ordinary chondrite falls and represent over 35% of well-classified, witnessed falls. As of late May 2017, Dokachi was one of 174 meteorite falls classified exactly as an H5 chondrite.

Approximately half of the mass was retained by the Geological Survey of India (Calcutta). ~ 500 g masses were also obtained by the Natural History Museum in London and by the Oxford University Museum.

Other Regions, Features and Areas containing this locality

References