Green glass vitrophyre 78526 - An impact of very low-Ti mare basalt compositionRake sample 78526 is an 8.77 g rock consisting primarily of vitrophyric pale green glass with subordinate mineral and lithic relics. Petrographic and compositional evidence leads to the following conclusions: (1) the bulk composition represents that of a mixture formed by impact melting of at least two different textural and compositional varieties of VLT mare basalt that are now present in the rock as lithic relics and a poorly defined low-Ti mare basalt component observed in thin section only in the form of isolated mineral relics; (2) the admixed VLT mare basalts had REE abundances lower than those found in other mare basalts (but probably higher than emerald green glass) and REE patterns showing significant enrichment of the heavy relative to light REE's, suggesting that they were derived by comparatively high degrees of partial melting of a clinopyroxene-rich source region; and (3) the impact melt supercooled to produce the vitrophyre, with rather sharply contrasting textural domains present in the vitrophyre resulting from differences in nucleation kinetics and degrees of supercooling in various portions of the sample.
Document ID
19790055118
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Warner, R. D. (New Mexico Univ. Albuquerque, NM, United States)
Taylor, G. J. (New Mexico Univ. Albuquerque, NM, United States)
Kiel, K. (New Mexico Univ. Albuquerque, NM, United States)
Planner, H. H. (New Mexico, University Albuquerque, N. Mex., United States)
Nehru, C. E. (Brookyn College Brooklyn, N.Y., United States)
Ma, M.-S. (New Mexico Univ. Albuquerque, NM, United States)
Schmitt, R. A. (Oregon State University Corvallis, Ore., United States)