Middle-Upper Miocene paleogeography of southern Turkey: insights from stratigraphy and calcareous nannofossil biochronology of the Olukpınar and Başyayla sections (Mut-Ermenek Basin)

"The age of the marine succession capping the basement rocks of the central Taurides in the Mut-Ermenek Basin is constrained. using calcareous nannofossil biochronology. The Olukpınar section, which correlates with the biozones between MNN5a and MNN6b. (late Langhian-late Serravallian), represents a deeper marine environment developed lateral to the Ermenek platform. The long-term. transgressive–regressive cycle of the Olukpınar section, which corresponds to the middle-upper part of the TB2 supercycle, can be. subdivided into 2 large-scale (106 years) cycles (TB2.4 and TB2.5) based on the occurrence of 2 major debris flow deposits linked. to sea-level drop. The younger late Tortonian Başyayla section represents a transgressive–regressive sedimentary cycle (TB3.2 cycle). responsible for the major transgressive event that occurred at the southern margin of the Central Anatolian Plateau during the Late. Miocene. This major transgressive event is responsible for the migration of the coastal onlap of the Mediterranean Sea towards the. interior of the Anatolian Peninsula, almost 100 km inland from the present Eastern Mediterranean coast line. The ~8 Ma age of the. younger marine sediments deposited during the TB3.2 cycle, which onlap the basement rocks of the central Taurides at an elevation of. ~2 km, represents a maximum age for the start of surface uplift of the Central Anatolian Plateau’s southern margin.

Biostratigraphy and magnetostratigraphy of the uppermost Tithonian–Lower Berriasian in the Theodosia area of Crimea (southern Ukraine)

We present evidence for the uppermost Jurassic-lowest Cretaceous interval in Crimea, coastal southern Ukraine. Three facies zones are distinguished in the upper Dvuyakornaya and the Mayak formations of the eastern Crimean Peninsula: basinal, slope and toe-of-slope zones. In this interval we identify the lowest Berriasian Jacobi and Grandis subzones of authors, in expanded form, exceeding 160 metres in thickness. We present new magnetostratigraphic interpretations, and identify two normal and two reversed polarity intervals, assigned to M19n, M18r, M18n and M17r, with M19n2n, M19n1r and M19n1n identified in the uppermost Dvuyakornaya Formation. In the Mayak Formation we record the top of M19n.1n, with M18r, M18n and a thick M17r above. In these two formations component calpionellid species have been identified which characterise the Alpina, Ferasini and Elliptica subzones (Calpionella Zone). In M19n, the FADs of the calcareous nannofossils Hexalithus strictus, Cruciellipsis cuvillieri, Nannoconus wintereri, N. steinmannii minor and N. kamptneri minor are found, which is consistent with other Tethyan regions. N. steinmannii steinmannii and N. kamptneri kamptneri first appear in M18r at Ili Burnu . Specimens of the apparently Tithonian foraminiferan index Anchispirocyclina lusitanica are found, but in the Berriasian lower Mayak Formation

An account of the bio- and magnetostratigraphy of the Upper Tithonian-Lower Berriasian interval at Le Chouet, Drôme (SE France).

24 pagesInternational audienceThis paper discusses the results of a study of the Le Chouet section, its lithologies, facies, magnetic properties and fossil record (ammonites, calcareous nannofossils, calpionellids and calcareous dinoflagellates). Data obtained have been applied to give a precise biostratigraphy for this carbonate sequence as well as a paleoenvironmental reconstruction. Its relationship to magnetostratigraphy, based on a modern study of a French site, is important. Investigation of the micro- and macrofossils shows that the site comprises a sedimentary sequence in the Microcanthum to Jacobi ammonite Zones, and the Chitinoidella, Crassicollaria and Calpionella Zones. Several calpionellid and nannofossil bioevents have been recorded on the basis of the distribution of stratigraphically important planktonic organisms. The site allows us to calibrate the levels of various biomarkers and biozonal boundaries, and correlate them with the magnetozones M20n, M19r and M19n