Ordinary chondrite (LL6; S2; W0)
Fell, 27 June 1966; 271 kg

After detonations and whistling sounds, a number of meteoritic stones fell on the towns of Severin and Allemans. The largest stone was 113 kg, but the eight recovered stones appear to be separated fragments of a single original stone. Total iron (20.17 wt%) and the composition of olivine and orthopyroxene indicate an LL classification. The meteorite has been almost completely recrystallized into a fine-grained matrix which lacks both chondrules and chondrule fragments. The groundmass is mostly olivine with lesser abundances of orthopyroxene and plagioclase. Undulose extinction and irregular fractures in the olivine indicate only moderate shock (level S2). Fe-Ni metal and troilite are present as rare grains (10-50 µm). The rare metal grains, however, are quite complex with plessite and tetrataenite in addition to kamacite and taenite. Accessory chromite, phosphates, traces of copper, and minor sulfides are also reported.

Pb-Pb and Rb-Sr ages (~4.5 Ga) indicate that the original parent body of the Saint-Séverin meteorite was formed during the early epoch of Solar System formation. A cosmic ray exposure (CRE) age of ~16 Ma may record the effect of a disruptive collision effecting most of the ~20% of all LL chondrites with similar CRE ages. [Presumably the target was a large fragment of the original parent body.]

St-Séverin is the most massive of the 42 meteorite falls classified exactly as 'LL6' chondrites at the Meteoritical Bulletin Database (April 2016). The LL chondrites are the smallest group of ordinary chondrites (~10% of all falls) with petrologic type LL6 accounting for approximately half of these falls. The main mass is at Museum National d'Histoire Naturelle (Paris).

Spelling Problematics: The meteorite has been listed as 'Saint-Séverin' in the latest versions of the Catalogue of Meteorites (1985; 2000) as well at the Meteorite Bulletin Database. However, versions of the name with and without the hyphen and with and without the acute accent regularly appear in the technical literature. [In addition, the abbreviation 'St-Séverin' usually lacks a period.]

Other Regions, Features and Areas containing this locality

References