The new polymict eucrite Dar al Gani 983: Petrography, chemical composition, noble gas record, and evolution

Abstract

Its texture is that of an impact breccia. It contains cumulate pyroxene and feldspar megacrysts, a variety of recrystallized melt clasts, clasts of subophitic basalt, and mesostasis. These components are embedded in a matrix of fragmental pyroxene and plagioclase. In addition, the entire rock is penetrated by glassy melt veins and patches, and displays features of strong shock. The mineralogical and chemical evidence obtained for DaG 983 indicates that this meteorite experienced a complex evolutionary history. The presence of cumulate silicate crystals implies substantial, large scale cratering events on the HED asteroid. As a result of these impacts, rocks from different intrusive bodies to extrusive surface layers were laterally and vertically transported to form a thoroughly mixed megaregolith. DaG 983 represents a sample of this megabreccia.

HED-like cosmic spherules from the Transantarctic Mountains, Antarctica: Major and trace element abundances and oxygen isotopic compositions

“…Field for chondrites and trends for achondrites are from Goodrich and Delaney (2000). The bulk compositions of eucrites, howardites and diogenites (HEDs) from literature are shown for comparison (McCarthy et al, 1973;Fukuoka et al, 1977;Floran et al, 1981;Cleverly et al, 1986;Laul and Gosselin, 1990;Lindstrom, 1993, 2003;Mittlefehldt, 1994;Kitts and Lodders, 1998;Barrat et al, 1999Barrat et al, , 2000Barrat et al, , 2003Barrat et al, , 2007Barrat et al, , 2009Buchanan et al, 2000;Papike et al, 2000;Patzer et al, 2003Patzer et al, , 2005Yamaguchi et al, 2009). is a reliable technique for a first identification of differentiated particles in large micrometeorite collections.…”

Characterization of achondritic cosmic spherules from the Widerøefjellet micrometeorite collection (Sør Rondane Mountains, East Antarctica)

“…8). For S-type cosmic spherules, Fe isotope fractionation appears to be negatively correlated with the FeO (1986), Lindstrom (1993, 2003), Kitts and Lodders (1998), Barrat et al (2000Barrat et al ( , 2007, Buchanan et al (2000), Patzer et al (2003Patzer et al ( , 2005 and Yamaguchi et al (2009). Reference values for 'mare basalts' from Haskin and Warren (1991).…”

“…Trace element compositions of the achondritic spherules. Reference values for 'eucrites' from McCarthy et al (1973), Cleverly et al(1986), Lindstrom (1993, 2003),Kitts and Lodders (1998),Barrat et al (2000Barrat et al ( , 2007,Buchanan et al (2000),Patzer et al (2003Patzer et al ( , 2005 andYamaguchi et al (2009). Reference values for 'mare basalts' fromHaskin and Warren (1991).…”

Significant depletion of volatile elements in the mantle of asteroid Vesta due to core formation

“…Measurements with significantly higher abundances of Ir (>1 ppb) and/or Tl (>5 ppb) than average for a particular sample were excluded from the database (Appendix section A.1). In addition to the eucrite database of Kitts and Lodders (1998) and references therein, we incorporated the results of several more recent studies (Gibson et al, 1985;Barrat et al, 2003Barrat et al, , 2007Patzer et al, 2005). For diogenites, our estimates are mainly based on the abundances reported by Wolf et al (1983), Gibson et al (1985) and Mittlefehldt (1994).…”