Wustite and native iron in Jurassic scorias of the north-eastern slope of the Lesser Caucasus (Azerbaijan).

Ismail-zadeh A. J., Kengerli T. N., Ahmedov A. М., Amirov A. S.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2018. V. 147. N 3. P. 16-27


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Language: Russian


Wustite (for the first time defined by authors at the territory of Azerbaijan) and the native iron have been found in the slag-like fragments of rocks (scorias) contained in the river alluvium above flood-plain terraces of Ganjachay and its small tributaries within the eastern periphery of Dashkesan trough (Lok-Garabagh zone of the Lesser Caucasus). They represent two following types of burnt, dense and lumpy bubble-rocks: 1) basaltoids with typical spinifex structure, containing native iron and magnetite, and 2) granitoids impregnated with different-size fragments of wustite, as well as magnetite, maghemite, etc. Rocks of the first type correspond to the low-titanium and komatiite-like ferro-magnesian formations (pyroxene komatiite — ?), while the second type is represented by diorites — quartz diorites. Data of the carried out analysis lead to a conclusion that wustite and other metal-bearing rocks have been brought to daylight by the hybrid magma of quartz diorites composition which was formed through mixing of the palingenic granitoid magma with the serpentinized rock of a buried ultrabasic plate. Studied samples represent fragments of substance from a deep magmatic chamber — ultrabasic rocks, recrystallized into komatiites (?), and fragments from marginal zones of the magma-generation chamber — melted granitoids with wustite, magnetite, maghemite, etc., ejected by an explosion activity of paleo volcanoes.

Key words: Jurassic magmatism, scoria, native iron, wustite, spinifex structure.