Qidong meteorite, Qidong Co., Nantong, Jiangsu, Chinai

Regional Level Types
Qidong meteorite	Meteorite Fall Location
Qidong Co.	County
Nantong	Prefecture
Jiangsu	Province
China	Country

Ordinary chondrite, xenolithic (L/LL5)
Fall, 2 July1982, 17:45 hrs; 1275 g

A single stone was recovered from an afternoon fall. Inspections reveal distinct chondrules which are frequently rimmed by Fe-Ni metal and/or troilite. Compositionally, olivine (Fa24.4) is homogeneous accompanied by moderately inhomogeneous low Ca-pyroxene (Fs19.2,av) [mostly orthopyroxene]. Analysis of major silicates, then, first suggested an L-chondrite classification. However, Qidong metal (mostly taenite accompanied by smaller amounts of relatively Co-rich kamacite) is indicative of LL-group membership. In time Qidong was thus eventually classified as a member of the small intermediate L/LL chondrite chemical group. Mineralogically, dominant olivine is accompanied by lesser amounts of pyroxene, Fe-Ni metal (~5 wt%), and troilite (~4 wt%). Minor plagioclase and accessory chromite are also present. Mosaicism in olivine plus fractured polycrystalline troilite and silicate grains provide pervasive indications of moderate shock. In addition, anomalous grains accompanying the shock facies (clinopyroxene, polycrystalline troilite, rare martensite) are texturally peculiar. Indeed, the presence of a few anomalous, relatively ferroan grains within the meteorite seems to provide additional evidence that both LL-chondrites and the LL-inclusions in L-chondrites are either late aggregates or contain late inclusions, respectively, of an earlier, less oxidized population of chondritic planetismals and home worlds. A cautionary note. Although Qidong is a rather recent fall, studied specimens exhibit mild terrestrial weathering effects which may also complicate the analysis.

A cosmic ray exposure (CRE) age of ~2.8 Ma is reported.

Qidong is one of only 11 witnessed L/LL chondrite falls. The main mass has been with the Purple Mountain Observatory in Nanjing.

Other Regions, Features and Areas containing this locality

References