Juromenha meteorite, Alandroal (Nossa Senhora da Conceição), São Brás dos Matos (Mina do Bugalho) e Juromenha (Nossa Senhora do Loreto), Alandroal, Évora, Portugali

Regional Level Types
Juromenha meteorite	Meteorite Fall Location
Alandroal (Nossa Senhora da Conceição)， São Brás dos Matos (Mina do Bugalho) e Juromenha (Nossa Senhora do Loreto)	Parish (Former)
Alandroal	Municipality
Évora	District
Portugal	Country

Iron meteorite, ataxite (IIIAB, D)
Fell,14 Nov 1968; 25.25 kg

A meteorite struck slightly moist soil with a deafening blast, created a hole .8 meters deep, and came to rest as a single roughly ellipsoidal mass (30 x 20 x 10 cm). Like many meteorites, one surface is smoothly domed, while the opposite surface is characterized by distinct regmaglypts. The interior, however, is not your usual medium-sized iron meteorite. While compositionally similar to many octahedrites, the ataxitic interior is dominated by small polycrystalline kamacite grains, assorted small blebs of taenite, a multitude of tiny phosphide grains, and other features that suggest a sudden melting (shock melting!?) followed by quick cooling. Such events would have prevented the development of the normal Widmanstätten pattern and exsolved minor accessories normally observed in IIIAB irons. The oxide crust is two-phased, composed of wüstite, FeO and magnetite, Fe304 . Cosmic exposure ages of 30-35 million years have been reported.

Juromenha is one of only 11 witnessed falls of IIIAB meteorites. The main mass is with the Center of Geological Studies in Lisbon.

Other Regions, Features and Areas containing this locality

References