Otis meteorite, Rush County, Kansas, USAi

Regional Level Types
Otis meteorite	Meteorite Fall Location
Rush County	County
Kansas	State
USA	Country

Ordinary chondrite (L6)
Find, 1940; 2.6 kg

One Abe Hartman sent a sample to the Nininger Laboratory for testing after reading a notice in a local newspaper. Inspections reveal indistinct chondrules and chondrule fragments within a largely equilibrated matrix. Compositionally, equilibrated olivine (Fa24) and low Ca-orthopyroxene ('hypersthene') are characteristic of the L-chondrite geochemical group. Mineralogically the meteorite consists primarily of dominant olivine along with pyroxene plus minor feldspar, troilite and Fe-Ni metal. Accessory chromite, ilmenite, and isocubanite also have been reported. The absence of reported taenite in Ramdohr (1973) suggests the possibility of extensive weathering.

A relatively short U-He age of ~520 Ma may be indicative of a major collision involving an important intermediate parent body (IPB) for a large number of L chondrites ~ 500 Ma ago. K-Ar dating also points to some even earlier collisions, but with less consistency. K-Ar dating of Feldspar separates yield an age of 4.23 Ga, but K-Ar dating of olivine, pyroxene, and bulk separates suggest a K-Ar age of ~2.3 Ga. Diffusion losses and weathering have been invoked as the culprit for these odd inconsistencies.

As with many meteorites collected by Harvey Nininger, the main mass remains at Arizona State University's Center for Meteorite Studies [735.3 g in 2017].

Other Regions, Features and Areas containing this locality

References