Following detonations, a shower of stones numbering more than 1000, and weighing ~500 kg, fell at 5:00 P.M. in the Ukraine, USSR. A strewnfield with dimensions of 2 × 0.75 miles was delineated. The nearly spherical mass of Knyahinya had an estimated pre-atmospheric diameter of 90 cm, corresponding to a mass of ~1,3001,400 kg, before it was broken into two nearly symmetrical sections upon impact; the largest section weighed 293 kg. The CRE age of Knyahinya as inferred from cosmic-ray track data and cosmogenic Ne ratios is 38 m.y. Knyahinya has proven to be instrumental in studies of cosmogenic nuclide production systematics due to its simple single-stage exposure history and its simple shielding geometry, allowing exact depth profiles to be determined.
Although Knyahinya has an accepted classification of L5 based on its trace element composition, it is partially resolved into an intermediate L/LL chondrite group based on studies involving the Co abundance in matrix kamacite and on its bulk metallic iron content similar to that of an LL chondrite. Contrariwise, the Ir/Au atomic ratio of Knyahinya falls within the H range (3.43.8) rather than the LLL range (2.63.5).
It was demonstrated by Szurgot (2016) that the mean atomic weight (Amean) of meteorites can be used to resolve the OC groups, including the intermediate groups L/LL and H/L. Amean values can also be predicted through various equations based on other parameters such as atomic Fe/Si ratio, grain density, and magnetic susceptibility, and these Amean values all consistently resolve these groups into the ordered sequence LL < L/LL < L < H/L < H. Knyahinya has Amean values of 23.24 (chemical composition), 23.21 (Fe/Si atomic ratio), and 23.54 (grain density). Furthermore, it was demonstrated that Amean values are lower for unequilibrated type 3 samples than for equilibrated samples within each OC group due to the presence of water; Amean values for petrologic types 46 are indistinguishable within each group.
Diagram credit: M. Szurgot, 47th LPSC, #2180 (2016) Amean based on chemical composition (Eq. 1), Fe/Si atomic ratio (Eq. 2), and grain density (Eq. 3)
Members of the L/LL chondrite group include L/LL3 Esperance, L/LL4 Seemore Downs, Bjurböle, and Cynthiana, L/LL5/6 Sahara 97021, and L/LL6 Acfer 041, as well as the partially resolved L/LL3 Inman and L/LL6 Holbrook. In a study of the shock stage of Knyahinya conducted by Fürj et al. (2009), mosaicism in olivines and twinning in pyroxenes were detected consistent with a shock stage of S4. The specimen of Knyahinya shown above is a 1.93 g partial slice. The photo below shows a print depicting the Knyahinya fireballfrom a book published in Denmark a few years after the fall (click image for title page). [A description posted online: "Mr. Kolbay's drawings of what he and Mr. Rainer saw from near Eperies (today Prešov, Slovakia), ~92 km from the Knyahinya strewnfield, as presented by W. R. v. Haidinger in 1866."]
Photo courtesy of Lars Pedersen
The largest mass of Knyahinya weighs 293 kg, which is curated at the Natural History Museum, Vienna.