THE TUCSON UNGROUPED IRON METEORITE: A STEP IN DECIPHERING ITS ENIGMATIC ORIGIN.

VARELA, MARIA EUGENIA; KURAT G,; ZINNER E; BRANDSTAETTER F,

Houston

Conferencia; Lunar and Planetary Science Conference; 2010

Lunar and Planetary Institute- NASA

Tucson is an enigmatic ataxitic iron meteorite, an assemblage of reduced silicates [1] arranged in sub-parallel flow-like structures [2], embedded in reduced metal with dissolved Si and Cr [3]. Both, silicates and metal, contain a record of formation at high temperature (~1800 K) and fast cooling. The latter resulted in the preservation of abundant glasses [4] and fine-grained metal. The chemical composition of silicate and metal phases led Bunch and Fuchs [5] to point out that Tucson shows similarities with enstatite chondrites and achondrites. This possible relationship was also support by others [6]. However, Tucson silicates have also isotopic and chemical similarities with constituents from carbonaceous chondrites such as Bencubbin, Kakangari and Renazzo [7].