Roda meteorite, Roda de Isábena, Isábena, Huesca, Aragon, Spaini

Regional Level Types
Roda meteorite	Meteorite Fall Location
Roda de Isábena	- not defined -
Isábena	Municipality
Huesca	Province
Aragon	Autonomous Community
Spain	Country

Diogenite
Fell Spring 1871, 400 g


A single stone was recovered in the province of Huesca, Spain. Pieces of it have been distributed widely and it was briefly considered as a type specimen for the 'rodite' meteorite class. In the main, however, Roda is usually considered a fairly normal diogenite (a plutonic pyroxenite) and one of only 11 witnessed diogenite falls. In addition to the dominant orthopyroxene (~90 vol%), accessories such as plagioclase (bytownite), troilite, and chromite are often observed in other diogenites. Minor amounts of silica, two phosphates, and olivine are also reported. While olivine is not found in all diogenites, it is not rare in diogenites and a few olivine-rich diogenites have recently been discovered. Small amounts of Fe-Ni metal and sulfides are also found in a surprising variety of phases. Sulfides include Mackinawite and Pentlandite — normally indicating somewhat lower oxygen fugacities than expected in diogenites. And although kamacite and taenite are unsurprisingly reported by several observers, much of the Fe-Ni metal is moderately Ni-poor (w. 2-5 wt% Ni ) while small pockets of Fe-Ni-Co metal have Ni > 50 wt% with up to 27 wt% Co. Perhaps Roda does not need to be given a special designation as a 'rodite', but its peculiarities may still deserve some special attention.

Roda's cosmic ray exposure age (~40 million years) appears similar to an apparent cluster in the exposure ages of several eucrites. As a member of the HED clan of meteorites (Howardites-Eucrites-Diogenites), it appears quite likely that Roda was ejected by impact from the asteroid 4 Vesta and may have shared part of its long journey with other HED meteorites. Two very deep impact craters on Vesta would readily have dispersed plutonic rocks into regions of space where collisions, orbital perturbations, and happenstance could eventually deliver a few fragments to the earth. However, it has also become clear that not all HED meteorites are derived from the same homeworld. We will presumably have to wait sometime before we can definitively assign specific HED meteorites to specific asteroidal parent bodies.

Meteoritical Bulletin Database coordinates put it outside Isábena boundaries. Initial description (Report of the ... Meeting of the British Association for the Advancement of Science for 1875) puts it 2km from Rhoda.

Other Regions, Features and Areas containing this locality

References