from The Meteoritical Bulletin No. 91, Meteoritic & Planetary
Science 42, 413-466 (2007)
Dhofar 1428
Oman
Find: March 2006
Achondrite (Lunar anorthositic breccia)
Physical characteristics: A 213 g dark gray stone with
little remaining fusion crust found within the desert of the Dhofar regions
of Oman. Petrography: (T. Bunch and J. Wittke, NAU) Clast-rich
impact melt breccia (mingled) that consists mostly of light to dark gray
clasts of previously formed, plagioclase-rich breccias and white lithic
and mineral clasts of anorthositic rocks and plagioclase. Minor amounts
of norites, anorthositic gabbros, troctolites, and ophitic/subophitic basalts
were also observed. Groundmass is composed of quench-textured silicate melt
(plagioclase, pyroxenes, opaque minerals and glass) and isolated pockets
of vesicular glassy melt. Geochemistry: Anorthositic clast
plagioclase (An93.8-98); Norite olivine (Fa36, FeO/MnO = 104), plagioclase
(An96.4), orthopyroxene (Fs28.4Wo4.1, FeO/MnO = 51); Troctolite plagioclase
(An95.5), olivine (Fa25.8, FeO/MnO = 89); Subophitic basalts that contain
highly zoned pyroxenes (Fs14.9Wo5.1 to rims of Fs41.2Wo15.2). Classification:
Achondrite (Lunar anorthositic breccia); Components shock levels range from
moderate to completely melted and the degree of interior weathering is very
low. Specimens: A 20.7 g type sample is on repository at
NAU. Mr. R. Ward holds the main mass.
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Chips
of Dhofar 1428 (Photo by Randy Korotev)
