Resedimented Limestones in Middle and Upper Jurassic Succession of the Slovenian Basin

Abstract

The Middle and Upper Jurassic succession of the Slovenian Basin is characterized by pelagic sedimentation of siliceous limestones and radiolarian cherts. In the southern and central part of the basin two packages of resedimented limestones are interbedded within pelagic sediments. The Lower resedimented limestones are lower-middle Bajocian to lower Callovian in age. In the southern part of the basin they form laterally discontinuous sequences composed of limestone breccias, calcarenites and micritic limestone and in the central part of the basin calcarenite intercalations within pelagic beds. They were transported by turbidity currents from highly productive ooidal shoals of the Dinaric Carbonate Platform. The Lower resedimented carbonates correlate with the lower three members of the Travnik Formation in the Bovec Trough and similarly developed but much thicker Vajont Formation in the Belluno Basin. The difference in thickness is interpreted as a consequence of shallow-water and longshore currents on the Dinaric Carbonate Platform that transported platform material towards southwest in the direction of the Belluno Basin. The Upper resedimented limestones are upper Kimmeridgian to lower Tithonian and occur within radiolarian cherts in the upper part of the succession as calcarenite beds that originated by turbidity currents. Onset of resedimentation coincides with the emersion-related demise of barrier reef and following deposition of micritic and rare oolitic limestones on the Dinaric Carbonate Platform. Approximatelly coeval resedimented limestones occur in the fourth member of the Travnik Formation in the Bovec Trough, but are not reported from the Ammonitico Rosso Superiore Formation in the Belluno Basin. Kratka vsebinaSrednje in zgornje jursko zaporedje Slovenskega bazena ozna~uje prevladujo~a pelagi~na sedimentacija okremenjenih apnencev in radiolarijskih ro'encev. V ju'nem in srednjem delu bazena se med pelagi~nimi plastmi pojavljata dva nivoja presedimentiranih apnencev. Spodnji presedimentirani apnenci so odlo'eni v srednjem delu zaporedja in so spodnje ali srednjebajocijske do spodnjecalovijske starosti. V ju'nem delu bazena tvorijo lateralno prekinjene apnen~eve horizonte, ki jih sestavljajo apnen~eve bre~e, kalkareniti in mikritni apnenci. V srednjem delu bazena pa se pojavljajo kot posamezne kalkarenitne plasti okoli meje med okremenjenimi apnenci in radiolarijskimi ro'enci. Ti apnenci so nastali s presedimentacijo materiala s turbiditnimi tokovi iz visoko produktivnih ooidnih plitvin Dinarske karbonatne platforme. Spodnje presedimentirane apnence koreliramo s spodnjimi tremi ~leni Travni{ke formacije v Bov{kem jarku in podobno razvito, vendar mnogo debelej{o Vajont formacijo v Belluno bazenu. Razlike v debeline so predvidoma nastale kot posledica plitvovodnih tokov na Dinarski karbonatni platformi, ki so transportirali platformski material proti jugozahodu v smeri Belluno bazena. Zgornji presedimentirani apnenci so zgornjekimmeridgijske do spodnjetithonijske starosti in se pojavljajo med radiolarijs...

Variety of Black and White Limestone Tesserae Used in Ancient Mosaics in Slovenia

“…In the wider area of Slovenia, two possibilities exist. First, black deeper‐water limestones could derive from the Jurassic Perbla and Tolmin Formations, which outcrop in the foothills of the Julian Alps (Rožič ; Rožič and Popit ; Rožič and Šmuc ; Fig. (a)).…”

Upper Triassic‒Middle Jurassic resedimented toe-of-slope and hemipelagic basin deposits in the Dinaridic Ophiolite Belt, Zlatar Mountain, SW Serbia

“…Since the euphotic conditions did not change significantly on the ADCP, from that time this platform may have been the only source of the redeposited shallow-marine carbonate grains. Accordingly, the Bajocian-Bathonian (?Callovian) limestone breccia (debrite) and graded oolitic, bioclastic limestone successions (Tolmin Formation) of toe-of-slope facies reported from the Slovenian Basin (Rožič and Popit 2006;Rožič et al 2018) were derived from the ADCP. Similar Middle Jurassic redeposited lithoclastic and oolitic, bioclastic toe-of-slope facies were also described from the Croatian segment of the ADCP foreland (Dragičević and Velić 2002;Bucković et al 2004).…”

Deep-water Triassic and Jurassic beds from Mt. Kobla (W Slovenia)

“…Radiolarijski roženec pripada zgornjemu ~lenu Tolminske formacije (ROŽI~ & POPIT, 2006; ROŽI~, v tisku), medtem ko spodnji ~len Tolminske formacije (kremenasti apnenci in roženci) ter Perblanska formacija (laporovci) na sami Kobli nista razgaljena. Ta del zaporedja izdanja in je bil nedavno preu~en približno kilometer zahodneje, na južnih pobo~jih Bohinjskega grebena med ^rno prstjo in Koblo (ROŽI~, v tisku).…”