Rush Creek meteorite, Kiowa County, Colorado, USAi

Regional Level Types
Rush Creek meteorite	Meteorite Fall Location
Kiowa County	County
Colorado	State
USA	Country

Ordinary chondrite (L6)
Find, 1938; 9.3 kg

Three fragments of a single stone were found. After the meteorite had been on display at the Kit Carson bank, two fragments were sent to the Nininger Laboratory for identification. Inspections reveal indistinct chondrules within a largely equilibrated and recrystallized matrix. Compositionally, equilibrated olivine (Fa26) and low Ca-orthopyroxene ('hypersthene') are characteristic of the L-chondrite geochemical group. Mineralogically the meteorite consists primarily of dominant olivine accompanied by pyroxene with minor troilite and Fe-Ni metal. Small grains of Fe-Ni metal and larger troilite grains are usually found within the largely recrystallized silcate-dominated matrix. Accessory chromite, copper, ilmenite, and other minor sulfides have been reported. Isocubanite, mackinawite and pentlandite observed by Ramdohr (1973) were deemed as 'primary' (pre-terrestrial) minerals, presumably due to textural features. Isotope studies could confirm or rebut this important conclusion. These 3 sulfide minerals are found both as preterrestrial products and as post-terrestrial weatherates in ordinary chondrites — and are unusually sensitive to oxygen fugacities in both the prevalent preterrestrial and post-terrestrial environments. Limonite weathering products are prominent in cracks and other regions.

The main mass is at the United States National Museum (2.9 kg) with several masses in the ~300-600 g range held elsewhere. Like many other meteorites collected by Harvey Nininger, one mass is now at Arizona State University's Center for Meteorite Studies [0.4405 kg in 2017 update].

Other Regions, Features and Areas containing this locality

References