Arcadia meteorite, Valley Co., Nebraska, USA

Latitude & Longitude (WGS84):	41° 25' North , 99° 6' West
Latitude & Longitude (decimal):	41.41667,-99.10000
Non-native locality type:	Meteorite
Köppen climate type:	Dfa : Hot-summer humid continental climate

Ordinary chondrite, veined (LL6; S1; W)
Find,1937; 19.4 kg

A weathered meteoritic stone with prominent 0.5-1.0 µm thick veins was recovered. Equilibrated olivine (Fa29) and low Ca-orthopyroxene compositions are characteristic of the LL-chondrite geochemical group. Mineralogically, the meteorite consists primarily of olivine and lesser pyroxene with minor amounts of plagioclase, troilite, and Fe-Ni metal. Troilite is more abundant than Fe-Ni (predominantly or exclusively kamacite). Troilite is usually more abundant than Fe-Ni metal in LL chondrites — but extensive weathering has presumably altered the original pre-terrestrial proportions. Accessory chromite, copper, and ilmenite are also reported. Sharp extinction of olivine and plagioclase are consistent with relatively mild level S1 shock. Weathering of the troilite has produced both goethite and marcasite.

The LL (relatively very low in total iron) chondrites are the third largest group of ordinary chondrites and represent ~8% of all recovered and classified witnessed falls. A cosmic ray exposure (CRE) age of 6.8 Ma has been reported.

Moderately large specimens are held at The Center for Meteorite Studies at Arizona State University (2.3035 kg in 2016) and the United States National Museum in Washington, D.C (1.465 kg in 2017).

Mineral List

8 valid minerals.

References

External Links