Microfauna, Palynomorphs, and Biostratigraphy of the Upper Bajocian Garantiana garantiana Zone (Middle Jurassic) of the Bolshoi Zelenchuk River Basin, North Caucasus.

Microfossils of the upper Bajocian Garantiana garantiana Zone of the Kyafar River (a tributary of the Bolshoi Zelenchuk River, Karachay-Cherkess Republic) are studied. The zone is represented by dark gray claystone-like clay series with sporadically scattered nodules, often forming interlayers, and is recognized in the upper subformation of the Djangura Formation. The taxonomic composition and distribution in the section of foraminifers, ostracods, dinoflagellate cysts, and miospores are studied. The range of foraminiferal and dinocyst biostratigraphic units and their correlation with the ammonite scale are established. On the basis of benthic foraminifera, these are Beds with Ophthalmidium caucasicum, corresponding to most of the Garantiana Zone, and Beds with Sublamarckella terquemi, corresponding to the upper part of the Garantiana Zone and the lower part of the Parkinsoni Zone. The Beds with Globuligerina dagestanica, recognized on the basis of planktonic foraminifera, are compared with the entire studied interval from the Garantiana Zone to the bottom of the lower Bathonian inclusive. The Beds with Meiourogonyaulax valensii and Rhynchodiniopsis? regalis (dinocysts) are considered equivalent to the entire range of the Garantiana Zone to the lower part of the Parkinsoni Zone inclusive. The key fossils are illustrated. [ABSTRACT FROM AUTHOR]