Monticello - a glass-rich howardite

Journal Article · Sun Mar 01 00:00:00 EST 1987 · Meteoritics; (United States)

DOI:https://doi.org/10.1111/j.1945-5100.1987.tb00885.x· OSTI ID:6166089

Olsen, E J; Dod, B D; Schmitt, R A; Sipiera, P P

Monticello is a new howardite similar to Malvern in that it contains abundant (15 percent) glass fragments, which show a range of compositions from olivine-normative to quartz-normative. Like Kapoeta, it contains pyroxene grains that range up to highly magnesian compositions, Fs16. Because their pyroxenes are more magnesian than those occurring in diogenites, Monticello and Kapoeta are exceptions to the simple two-component mixing model in which howardites are considered to be mechanical mixtures of fragmented eucrites and diogenites. Monticello also contains clasts of what appear to be a cumulate eucrite and a noncumulate eucrite, as well as a radiating pyroxene chondrule from a chondrite. Monticello is a regolith breccia containing more evolved components than are usually considered in eucrite-diogenite genesis models. As such, it supports those models that involve reworking of a complex parent body crust rather than straightforward partial melting of primitive chondritic parent material. 37 references.

• Research Organization: Field Museum of Natural History, Chicago, IL; Chicago Univ., IL; Mercer Univ., Macon, GA; Oregon State Univ., Corvallis; William Rainey Harper College, Palatine, IL
• OSTI ID: 6166089
• Journal Information: Meteoritics; (United States), Vol. 22
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
METEORITES
CHEMICAL COMPOSITION
GLASS
MAGNESIUM COMPOUNDS
OXYGEN ISOTOPES
PETROGRAPHY
PYROXENES
ALKALINE EARTH METAL COMPOUNDS
ISOTOPES
MINERALS
OXYGEN COMPOUNDS
SILICATES
SILICON COMPOUNDS
640107* - Astrophysics & Cosmology- Planetary Phenomena