Trans-border (South-Eastern Serbia/South-Western Bulgaria) correlations of the Jurassic sediments: The Getic and Supra-Getic units

Abstract

The Getic and Supra-Getic are palaeogeographic units in SE Serbia and SW Bulgaria. Based on the presence (in Eastern) or absence (in Western) of Lower Jurassic marine deposits, the Getic is divided into Eastern and Western. In the Eastern Getic, the Lower Jurassic sedimentation in SE Serbia is represented by the Vidlic Clastites covered by the Lukanja Coal Beds, Lukanja Quartz Sandstones, Lukanja Brachiopods Beds, Lukanja Marlstones, Lukanja Belemnitic-Gryphaean Beds and Lukanja Cephalopod Limestones; in SW Bulgaria, the sedimentation commenced with the Tuden Formation, followed by the Kostina Formation and the Ozirovo Formation with a few members. The Middle Jurassic in SE Serbia commenced with the Senokos Siltstones and Shales and the Gulenovci Beds, while in SW Bulgaria with black shales (the Etropole Formation), followed by marls and clayey limestones of the Bov Formation. The Middle Jurassic sediments are represented in the Western Getic of SE Serbia by the Kurilovo Clastites and the Kurilovo Limestones (synonym to Gumpina Limestones of KRA?TNER & KRSTIC 2003); in the Supra-Getic of SE Serbia they are formed by the Jerma Clastites and Jerma Limestones (synonym of the Gumpina Limestones). In SW Bulgaria the Middle Jurassic sediments are represented by the sandstones of the Gradets Formation and by the bioclastic limestones of the Polaten Formation. During the Callovian (Middle?) started the formation of a carbonate platform with micritic limestones. In SE Serbia, it is Basara Limestones, Vidlic Limestones, Beljanica and Zdrelo Limestones, and in SW Bulgarian, the Belediehan Formation of Callovian-Kimmeridgian p.p. age. Characteristic for the Supra- Getic is the formation of a few grabens with specific sedimentation: the Svetlya Graben (the Zhablyano and Ozirovo Formations) and the Lobosh Formation; the Treklyano Graben (the Dobridol and Sredorek Formations), and out of it - the Methohya and Sredorek Formation. During the Callovian-Kimmeridgian p.p., in the Svetlya Graben was sedimented the Lobosh Formation, horizontally passing into the Javorets and Gintsi Formations. During the latest Kimmeridgian-Tithonian commenced a big facial diversification: on the Getic in SE Serbia sedimented reef or sub-reef limestones (the Crni Vrh and Kucaj Reef Limestones), while in SW Bulgaria, the Slivnitsa Formation. On the Supra-Getic in SE Serbia formed Luznica Flysch and in SW Bulgaria pre-flysch of the Neshkovtsi Formation and siliciclastic flysch of the Kostel Formation.Getikum i Supra-getikum su paleogeografske jedinice u JI Srbiji i JZ Bugarskoj. Na osnovu prisustva i odsustva lijaskih morskih sedimenata Getikum je podeljen na istocni i zapadni. U istocnom Getiku jurska sedimentacija je predstavljena, u JI Srbiji, sa vidlickim klastitima preko kojih leze lukanjski ugljeviti slojevi, lukanjski kvarcni pescari, lukanjski brahiopodski slojevi, lukanjski laporci, lukanjski belemnitsko-grifejski slojevi i lukanjski amonitski krecnjaci, a u JZ Bugarskoj sedimentacija pocinje tudenskom formacijom preko koje leze kostina formacija i ozirovska formacija sa nekoliko clanova. Srednja jura JI Srbiji pocinje sa senokosnim alevrolitima i skriljcima i gulenovackim slojevima, dok u JZ Bugarskoj pocinje sa crnim skriljcima entropolske formacije, zatim laporcima i glinovitim krecnjacima bovske formacije. Srednjojurski sedimenti u zapadnom Getikumu istocne Srbije predstavljeni su kurilovskim klastitima i kurilovskim krecnjacima (gumpina krecnjaci, KRA?TNER & KRSTIC 2003). U Supra-Getikumu Srbije nastaju jermski klastiti i jermski krecnjaci (gumpina krecnjaci). U JZ Bugraskoj srednjojurski sedimenti su predstavljeni pescarima gradecke formacije i bioklasticnim krecnjacima poletenske formacije. Za vreme keloveja (srednjeg ?) pocinje formiranje karbonatne platforme sa mikritskim krecnjacima. U JI Srbiji to su basarski krecnjaci, vidlicki krecnjaci, beljanicki ili zdrelski krecnjaci, a u JZ Bugarskoj to je belediehanska formacija kelovejsko-kimeriyske p.p. starosti. Karakteristicno za Supra-getikum je formiranje nekoliko rovova sa specificnom sedimentacijom: svetlajski rov (zabljanska i ozirovska formacija) i loboska formacija, trekljanski rov (dobridolska i rajanacka formacija) i van njih methohijska i sredorecka formacija. Za vreme keloveja i kimeriya p.p. u svetlajskom rovu se deponuje loboska formacija, koja bocno prelazi u javorecku i ginacku formaciju. Za vreme najkasnijeg kimeriy-titona nastaju velike facijalne raznolikosti: na Getikumu, u JI Srbiji se taloze sprudni i subsprudni krecnjaci (crnovrski krecnjaci i kucajski krecnjaci), dok se u JZ Bugarskoj formira slivnic ka formacija. Na Supra-getikumu u JI Srbija deponuje se luznicki flis, a u JZ Bugarskoj preflis neskovacke formacije i siliciklasticni flis kostelske formacije.