Petrology of the Indian eucrite Piplia Kalan

Abstract

Abstract-Piplia Kalan is an equilibrated eucrite consisting of 60-80 vol% lithic clasts in a subordinate brecciated matrix. Ophitichbophitic clasts fall into two groups: finer-grained lithology A and coarsergrained lithology B. Very fine-grained clasts with equigranular textures (lithology C) also occur and originally were hypocrystalline in texture. The variety of materials represented in Piplia Kalan suggests cooling histories ranging from quenching to slower crystallization. Despite textural differences, clasts and matrix have similar mineral and bulk compositions. Thus, Piplia Kalan is probably best classified as a genomict breccia that could represent fragments of a single lava flow or shallow intrusive body, including fine-grained or glassy outer margin and more slowly cooled coarser-grained interior. Bulk composition suggests that the meteorite is most closely related to the main group eucrites, but it probably was affected by minor amounts of fractional crystallization. Piplia Kalan displays evidence of an early shock event, including brecciated matrix and areas of lithic clasts that contain very fine-grained, granular pyroxene between deformed feldspar laths. The meteorite also displays evidence of at least one episode of extensive thermal metamorphism: hypocrystalline materials are recrystallized to hornfelsic textures and minerals throughout the meteorite contain abundant inclusions that are relatively large in size. Veins of brown glass transect both clasts and matrix and indicate a second, postmetamorphism shock event.

The South African polymict eucrite Macibini

“…The metavolcanic lithology C in the eucrite Piplia Kalan (Buchanan et variation in the degree of equilibration of these materials indicates al., 2000). This texture is also similar to terrestrial volcanic rocks that metamorphism occurred in large part before the final that were metamorphosed (Buchanan et al, 2000). Eucrite clasts aggregation of the meteorite.…”

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.…”

Glass veins in the unequilibrated eucrite Yamato 82202

“…Hence, based on the classification scheme of Takeda and Graham (1991), Y82202 probably should be classified as a type 1 or type 2 eucrite in terms of equilibration. In one respect, Y82202 is also similar in texture to the eucrite Piplia Kalan (Buchanan et al, 2000a), because available thin sections suggest that a relatively large proportion (ϳ50 vol.%) of the meteorite is composed of lithic clasts, whereas there is a relatively small proportion of brecciated matrix material compared to many other eucrite and howardite breccias. Yamaguchi and Takeda (1992) call this texture "partly brecciated.…”