@article{oai:nipr.repo.nii.ac.jp:00005949,
 author = {Yugami, Keiko and Takeda, Hiroshi and Kojima, Hideyasu and Miyamoto, Masamichi},
 journal = {Antarctic meteorite research},
 month = {Mar},
 note = {P(論文), The textures and trends of chemical variations of minerals in five acapulcoites (Acapulco, Allan Hills (ALH)-77081,ALH-78230,ALH-81187 and ALH-81261), two winonaites (Tierra Blanca and Yamato (Y)-74025) and an H7 chondrite (Y-75008) were studied for comparison to deduce their formation conditions and subsolidus cooling histories. The mineral distribution maps of polished thin sections (PTSs) of ALH-78230,Tierra Blanca, Y-74025,Y-75008,were made from elemental distribution maps of the electron probe microanalyzer to study variations in the distributions of minerals. Textures of these meteorites are fine-grained recrystallized chondrite-like materials including minerals known in chondrites. Opaque mineral grains have complex shapes, often with large aggregates of Fe-Ni metals, as was observed in Y-74025. Elongation parameters defined as L/(4πS)^<1/2> (=A), range from 1.4 to 1.6 for acapulcoites, where L is length and S is area of a grain. Despite their formation in different parent bodies, the variety of textures of primitive achondrites suggests that heterogeneity produced by local segregation of partially melted materials on their parent bodies can explain the origin of variation of primitive achondrites. CaO zoning of orthopyroxene can be attributed to the segregation and migration of Ca-rich partial melts. Mg/Fe variations of olivine can be explained by subsolidus reduction, when their parent body was disrupted or fractured by an impact while its interior was still hot.},
 pages = {117--138},
 title = {Comparisons of textural and chemical variations of minerals in some primitive achondrites and an H7 chondrite, with reference to their formation and cooling histories},
 volume = {12},
 year = {1999}
}