Upper Jurassic micrometeorites from Cañadon Asfalto Fm., Patagonia, Argentina. Lunar Planetary Science Conference

MATTEINI, MASSIMO; HAUSER, NATALIA; CABALERI, NORA; CUADRO, F.A.; MAGALDI, T.; PEREIRA, L.A.

The Woodlands, Texas

Congreso; 45 th Lunar Planetaray Science Conference; 2014

NASA

In this study we found only spherules that resemble particles known as ?melted micrometeorites´. Three main groups of melted micrometeorites have been recognized by several authors [2,3,4]: I-type, G-type and S-type. I-type are characterized by interlocked magnetite with interstitial wustite and represent ~1-2% of micrometorites from South Pole Water Well [2]. They often present sub-spherical voids probably formed by loss of a molten metal (Fe-Ni) blead. Gtype spherules are typically characterized by a dominant dendritic magnetite within a mesostasis of silicate glass and represent ~1 of micrometorites from South Pole Water Well [2]. They often present, as Itype spherules, sub-spherical voids. S-type spherules represent stony micrometeorite mostly composed by olivine, magnetite and glass. The mayority of the studied spherules show mineralogical, geochemical and textural features very similar to those reported for I-type micrometeorites whereas some spherules are interpreted as typical Gtype micrometeorites. Further researches are necessary to characterize these micrometeorites and better understand the accretion rate of micrometeorites during upper Jurassic, from the sedimentary recorde of Cañadon Asfalto Fm.