Kota-Kota meteorite (Marimba meteorite), Nkhotakota, Central Region, Malawii

Regional Level Types
Kota-Kota meteorite (Marimba meteorite)	Meteorite Fall Location
Nkhotakota	District
Central Region	Region
Malawi	Country

Enstatite Chondrite, high-iron (EH3; S4)
1905 find, 334 g, weathered


A stone ‘from the sky’ was presented to a district commissioner and after eventually reaching the Acting Commissioner for British Central African Office in 1905, the stone was duly transferred to the British Museum. In 1914 Prior noted the presence of chondrules, pyroxene, and rust. He further stated: “Owing to the weathered and rusted condition of the stone no chemical analysis was made, as it would have been of little value.”

The Enstatite Chondrite Class is defined by specific elemental ratios and by earthlike isotopic ratios. Mineralogically Enstatite Chondrites are characterized by the presence of iron-poor Enstatite, Fe-Ni metal, and a number of very reduced mineral phases (sulfides, nitrides, silicides) which are either unknown or very rare in terrestrial settings. The EH (high iron) chemical group is further characterized by abundant iron (~10-20 vol%) and the mineral niningerite. Type EH3 chondrites, the most abundant EH petrologic type, often contain perryite as well. They are additionally characterized by abundant chondrules, low degrees of aqueous alteration, and unequilibrated mineral assemblages. Kota-Kota’s Shock level [S4] indicates strong pre-terrestrial shock — a frequent complication in interpreting Enstatite Chondrite metamorphic histories. As the extremely reduced mineralogy of Enstatite meteorites makes several phases particularly susceptible to destructive weathering, it is all the more remarkable that the previously unknown mineral Djerfisherite, an alkali-containing sulfide, was discovered in 1965 amidst the chondrules, pyroxenes, and rust.

References

External Links

Other Regions, Features and Areas containing this locality