Б.Марковский и Д.Наливкин Задонские и Елецкие слои

SUMMARY The present work is a continuation of the work of D. Nalivkin L It contains; a part on stratigraphy written by B. Markovsky and a paleontological part writ­ ten by D. Nalivkin. The work is based on the collection of B. Markovsky in the Central Geological Museum, Leningrad. Stratigraphy ByB. M a r k o v s k y T h e Z a d o n s k b e d s . Resting upon the Livny beds and overlain by~ the Eletz beds. In the lower part an alternation of ferruginous sandstones, fer­ ruginous oolites, greenish-gray clay and marls. In the upper part — marls, clays- and limestones. Thickness 12— 15 m. The fauna in the lower part, especially in ferruginous sandstones and oolites, is scarce. The presence of Conularia is interesting. In upper part of the- Zadonsk beds the fauna is typical for the shallow-water region of the open sea and is characterized by abundance of brachiopods and pelecypods. Characteristic; forms are: Spirifer Archiaci Mur ch. , Productus orelianus М ое 11. For a general list of the fauna see page 7 of the Russian text. T h e E l e t z b e d s . Resting upon the Zadonsk beds and covered by the Dankovo-Lebedian beds. The massive and bedded limestones and dolomitized limestones. Thickness 30 — 33. m. The fauna consists chiefly of the brachiopods — Spiriferidae, Productidae and Athyridae. Other groups are scarce. Characteristic forms are: Spirifer Brodi Wen., Chonopectus rossicus n. sp., Athyris concentrica Buc h . 5 For a general list of the fauna see page 11 of the Russian text. C o m p a r i s o n o f t h e F a m e n n i a n of V o r o n e j e w i t h t h a t of We s t E u r o p e a n d t h e Ur a l s . Comparison of the upper part of the Voroneje section with the sections of West Europe, those of the North-Western country, the Timan and the Urals. The comparison of the upper part of the Voroneje section, that is of the beds of Zadonsk, Eletz and Dankovo-Lebedian, with those of West Europe is practically impossible, for the reason of a great difference of facies. In West: Europe exclusively sandstone and shale facies are developed, replaced at places by goniatite and Climenian limestones. In the Devonian of Voroneje the gonia- tite and Climenian facies are absolutely absent, the sandstone shale facies of the West-European type are also absent and limestones, marbles and clays are developed. Comparison of the West-European and Voroneje sections is possible only due to the presence of common forms and pecularities of the fauna. The Famennian horizon of West Europe is characterized by a great development of Spirifer 1 D. N[a 1i v к i n. The Semiluki and the Voroneje beds. 34