Modal studies of mesosiderites and related achondrites, including the new mesosiderite ALHA 77219The Antarctic meteorite ALHA 77219 is found to be a new mesosiderite. It contains about 25% metal + troilite (+ rust) and the brecciated silicate portion is dominated by orthopyroxene (En 68-71). These features, together with the presence of olivine surrounded by coronas, and abundant tridymite + phosphate conform to the characteristics of mesosiderites. A comparison of the modal abundances of minerals in 77219 with modes of 20 mesosiderites, 14 howardites, six basaltic eucrites, three feldspar cumulate eucrites, and one orthopyroxene cumulate eucrite shows that there are major differences between mesosiderites and howardites. These differences are described in detail.
Document ID
19820038775
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Prinz, M. (American Museum of Natural History New York, NY, United States)
Delaney, J. S. (American Museum of Natural History New York, NY, United States)
Harlow, G. E. (American Museum of Natural History New York, NY, United States)
Bedell, R. L. (American Museum of Natural History New York, NY, United States)
Nehru, C. E. (American Museum of Natural History, New York; Brooklyn College, Brooklyn NY, United States)