VOLKHOVITES
Volkhovites are very small-sized, aerodynamically-shaped
glasses having mafic to ultramafic compositions. They were discovered in
far-western Russia along the Volkhov River, southwest of St. Petersburg.
They have the texture & shapes of microtektites (= tiny impact splash
glasses). Published chemical analyses by the Russians indicate that
volkhovites have bulk compositions consistent with kimberlites, lamproites,
and carbonatites.
Their rare earth element compositions are similar to those seen in indochinites
(= 700 k.y. impact splash glasses found throughout much of the southern
portions of the Old World).
Despite their shapes and texture, the only available
published interpretations of volkhovites conclude that they are not impact
related, but are inferred to be outburst glasses from some not-yet-identified
cryptovolcanic eruption center (see Skublov et al., 2007). This
conclusion appears to be influenced by pseudoscientific or fringe science
thinking (see Izokh, 1997). I wouldn't be at all surprised to find out
that they are indeed impact related.
Locality:
riverbank exposure on eastern side of the Volkhov River at the town of Kirishi,
north of Novgorod, southwest of St. Petersburg, far-western Russia. ~59¼
27Õ North latitude, ~32¼ 01Õ East longitude.
Host materials & age: loamy glacio-fluvial sediments, Valday Glacial
Interval, Late Pleistocene, 10-65 k.y.
Volkhovites - yellowish brown, greenish, and blackish specimens ranging from
spheres to fused spheres to dumbbells to elongated threads of glass.
Scale:
yellowish dumbbell-shaped specimen at lower right is 3 mm long.
Synthesized from info. in:
Izokh (1997) - Australian-Asian tektites and global catastrophe
about 10,000 years ago caused by collision of the Earth with a comet. Geologiya
i Geofizika 38: 638-660.
Skublov et al. (2007) - Volkhovite: a new type of
tektite-like glass. Geology of Ore Deposits 49: 681-696.