Jackalsfontein meteorite, Beaufort West, Beaufort West Local Municipality, Central Karoo District Municipality, Western Cape, South Africai

Regional Level Types
Jackalsfontein meteorite	Meteorite Fall Location
Beaufort West	Town
Beaufort West Local Municipality	Municipality
Central Karoo District Municipality	District
Western Cape	Province
South Africa	Country

Ordinary chondrite, veined and black (L6)
Fell, April 1903, 11:30 hrs; 48 kg, 2 stones

After detonations, a very large stone and a very small stone fell near the boundaries of the Tamboersfontein and Jackalsfontein to the NW of Uitkujk. The meteorite contains a few moderately large round and angular fragments of various colors within an uneven, but — usually — lighter largely equilibrated matrix. Some small brownish regions and relic chondrules are present as well. Very small Fe-Ni particles are ubiquitous within the matrix. In places, heterogeneous veins with aggregates of shock-created microscopic darker particles are quite prominent. Compositionally, total iron contents (21.57 wt%) and olivine (Fa24) and low Ca-orthopyroxene ('hypersthene') are characteristic of the L-chondrite geochemical group. Mineralogically the meteorite consists primarily of dominant olivine and orthopyroxene along with minor troilite, Fe-Ni metal, and — presumably — plagioclase. Accessory chromite and a few other minor opaques have been reported. Diaplectic glass as well as devitrified glass represent one or more important shock and recrystallization events.

Argon (K-Ar) and helium (Pb,Th:He) gas release ages of 638 and 660 Ma, respectively, are likely reflections of a major collisional event by an important intermediate parent body (IPB) of the Jackalsfontein meteoroid. A cosmic ray exposure (CRE) age of t ~19 Ma reflects the meteoroid's final period before earth-encounter and could be the signature of a collision which involved other L chondrites in our collections.

The L-group of ordinary chondrites (relatively low in total iron) are the largest group of classified witnessed meteorite falls. The L6 petrologic type accounts for ~ 70% of the group. 272 meteorite falls had been classified exactly as 'L6' chondrites by early June 2017. While Bruderheim (200 kg) and 17 other L6 chondrite falls were more massive, Jackalsfontein's 48 kg mass is still well within the most massive 10 percentile of L6 falls. Indeed, small samples of Jackalsfontein have been available for several statistically oriented textural studies of meteorite shock.

The main mass has been kept at the South African Museum in Capetown.

Other Regions, Features and Areas containing this locality

References