The palynology of the Kimmeridge Clay and Carstone formations (Upper Jurassic – Lower Cretaceous) at Middlegate Quarry, North Lincolnshire, UK, and its biostratigraphical and palaeoenvironmental significance

At Middlegate Quarry, the Carstone Formation is an approximately 0.8 m thick unit of oolitic ferruginous sandstone. It rests unconformably on the lower Kimmeridge Clay Formation (KCF) and is overlain by the Hunstanton Formation (Red Chalk) with an apparently gradational junction. Marine dinoflagellate cysts (dinocysts) are present at a concentration of 9,520 to 13,600 specimens per gramme in the 0.15 m of KCF below the unconformity, and include taxa that confirm ammonite evidence for the intra-Lower Kimmeridgian Substage (Upper Jurassic, Cymodoce Ammonite Zone). A rich recovery of well-preserved Lower Cretaceous palynomorphs is reported for the first time from the overlying Carstone. Reworking of mudstone from the KCF into the formation appears to have provided a local argillaceous preservation matrix at Middlegate. The basal 0.15 m is dominated by palynomorphs derived from the KCF but the interval from 0.15 m to 0.55 m above the unconformity mainly contains indigenous Lower Cretaceous palynomorphs. Dinoflagellate cysts are present in the Carstone at an average concentration of 454 specimens per gramme, and include taxa that probably have stratigraphical range bases above the Aptian – Albian stage boundary; Cyclonephelium compactum, Cyclonephelium intonsum, Endoscrinium heikeae, Leptodinium cancellatum (consistent), Stephodinium coronatum and Stephodinium spinulosum. The additional presence of taxa with range tops / event tops in the Lower Albian Tardefurcata Ammonite Zone (common Cauca parva, frequent Canninginopsis monile and Kleithriasphaeridium eoinodes, and rare Dingodinium albertii, Discorsia nannus and Kiokansium prolatum) indicate probable assignment to this zone. The new palynological data support previous macrofossil (brachiopod) study of the Carstone at Middlegate and nearby Melton Bottom Quarry which tentatively assigns its highest part to the Tardefurcata Zone. The palynological and palynofacies assemblages are interpreted to confirm a relatively proximal to shoreline site of deposition, possibly inner to middle neritic.Supplementary material: One pdf file, with quarry photographs and a palynological distribution chart, is available at https://doi.org/10.6084/m9.figshare.c.5538977

Kimmeridgian and early Tithonian cephalopods from the Kisújbánya Limestone Formation, Zengővárkony (Mecsek Mountains, southern Hungary), their faunal composition, palaeobiogeographic affinities, and taphonomic character

A new collection at Zengővárkony (Mecsek Mountains, Hungary) provided a rich and diverse but poorly preserved cephalopod-dominated fossil assemblage representing the Kimmeridgian and the lower Tithonian. The material came from mixed scree, soil, and amongst roots affected by weathering processes having been exposed to the elements for a long time. The nautiloid Pseudaganides strambergensis is the first record from the Mecsek Mountains. Due to the weathering, the ammonite fauna consists of mainly fragmentary and dissolved individuals that comprises 528 specimens belonging to 34 species and 30 genera out of which 20 species and 15 genera are reported for the first time from the Mecsek Mountains. The fauna includes specimens of known taxa. No new taxa are introduced. Based on the comparison with other faunas, this assemblage most closely resembles the fauna of the Venetian Alps (Italy). Additional faunal elements include aptychi (Laevaptychus latus, Lamellaptychus murocostatus), belemnites (Hibolithes semisulcatus), and an indetermined brachiopod. The first record of Spiraserpula spirolinites, an encrusting fossil polychaete preserved on the internal mould of a Taramelliceras shell fragment indicates favourable bottom conditions for the epifauna. The presence of Aspidoceras caletanum, Gravesia aff. gigas, and Pseudowaagenia inerme indicates faunal connections with the Submediterranean Province of the Tethys, which is in line with the tectonic and palaeogeographical position of the Mecsek Zone during the Late Jurassic. The ammonite assemblage represents elements of five Tethysian ammonite zones of the Kimmeridgian and Tithonian. The lower Kimmeridgian Herbichi Zone is indicated by Streblites tenuilobatus and Praesimoceras herbichi. The upper Kimmeridgian Acanthicum Zone is indicated by Aspidoceras acanthicum, and the Cavouri Zone by Mesosimoceras cavouri and Aspidoceras caletanum. The upper Kimmeridgian Beckeri Zone is suggested by Hybonoticeras pressulum and Pseudowaagenia inerme. Whereas Gravesia aff. gigas, Lithacoceras aff. siliceum, and Malagasites? denseplicatus are faunal elements characterising the Early Tithonian Hybonotum Zone. Phylloceratid and lytoceratid specimens account only for 12% of the fauna, while the majority of the specimens belong to the Oppeliidae and Ataxioceratidae (60%).

Biostratigraphy of Upper Jurassic of the Valy clay pit (Samarskaya Luka) by ammonites, ostracods and dinocysts

The results of integrate biostratigraphic study of Upper Jurassic deposits of the clay pit near the village of Valy (Syzran district, Samara region) are presented. For the first time a bed-by-bed description was made and the subdivision of the section into zones, subzones and biohorizons by ammonites was established. Bauhini and Kitchini zones (Bayi subzone) are established in the Lower Kimeridgian, while Upper Kimmeridgian is represented by Autissiodorensis zone only. In the Lower Volgian Sokolovi and Pseudoscythica zones were recognized, while the Middle Volgian is represented by the Panderi zone. The age of the regionally developed unconformity at the base of the Trazovo Formation has been clarified. As in the sections located to the south from studied section, this unconformity is located in the base of the Autissiodorensis zone, overlying different Oxfordian and lower Kimmeridgian. For the first time for Kimmeridgian of Central Russia in the marlstone band of the Kitchini zone (bayi biohorizon) solitary corals conditionally attributed to the genus Trochocyathus were found. Along with corals other warm-water taxa (belemnites Hibolithes, rare ammonites Taramelliceras) were found in the same bed, suggesting deposition of this bed during the short-time warming event. 6 biostratigraphic units (zone and beds with fauna) were recognized by ostracods, along with 2 dinocyst-based units (assemblage and zone) which are compared with the stratigraphic subdivisions by these groups, previously proposed for the Kimeridgian and Volgian stages of the Russian Platform. The paleo-ecological analysis has allowed to assume, that sediments have accumulated in the conditions of warm shallow eutrophic basin with depth to 50 m, with gradual increase of eutrophy through time. At some levels, short-term episodes of severe shallowing or freshening are recorded by ostracods.

First records of Somalinautilus (Cephalopoda: Nautiloidea) from the Jurassic of Southern Germany – inferences for trans-provincial migrations

The Late Jurassic nautiloid Somalinautilus antiquus (Dacqué, 1910), previously only known by the holotype from Lower Kimmeridgian strata of Ethiopia, is reported from the Lower Kimmeridgian (Platynota Zone) of Southern Germany. This unexpected record largely expands the known geographic distribution of this species. Another species of Somalinautilus, S. clavifer Tintant , 1994, is recorded for the first time from the Middle Jurassic (Lower Bathonian, Zigzag Zone) of Southern Germany. A short stratigraphic and palaeogeographic review of Somalinautilus occurrences is provided. Faunal migrations of nautiloids over large distances were probably triggered by sea- level highstands and/or palaeocurrents.

Biostratigraphic partition of the Upper Jurassic and Lower Cretaceous (Oxfordian - Lower Berriasian) deposits of the Crimean Mountains for foraminiphers

Introduction. Upper Jurassic and Lower Cretaceous deposits in the Crimean Mountains are widespread and are represented by all stages ‑ Oxfordian, Kimmeridgian, Tithonian, and Berriasian. These deposits have been unevenly studied. The most studied deposits are the Oxfordian, Tithonianian and Berriasian stages. The biostratigraphic division of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea is based on "Stratigraphic scheme of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea" 2013. Purpose. Detailed biostratigraphic devision of the Upper Jurassic and Lower Cretaceous (Oxfordian ‑ Lower Berriasian) of the Mountain Crimea as results of foraminiferal analysis. Results of the study. There are five foraminiferal complexes in sections that characterize Upper Jurassic (Lower Upper Oxfordian, Lower Kimmeridgian, Upper Tithonian) and Lower Cretaceous (Lower Berriasian) age. Analysis of foraminiferal complexes allowed us to establish biostratigraphical zones in each section: oxfordiana in the Lower Oxfordian Lenticulina quenstedti-Globuligerina; in the Upper Oxfordian Lenticulina russiensis-Epistomina uhligi; in the Upper Tithonian Anchispirocyclina lusitanica-Melathrokerion spirialis; in the Lower Berriasian (lower zone) Protopeneroplis ultragranulatus-Siphoninella antiqua and layers in the Lower Kimmeridgian with Epistomina praetatariensis-Globuligerina parva. Specified foraminiferal zones were traced by us in different structural-facial zones (zone Lenticulina quenstedti-Globuligerina oxfordiana ‑ in Sudak-Feodosia; zone Lenticulina russiensis-Epistomina uhligi ‑ in Ai-Petri-Babugansk and Sudak-Feodosia; strata layers with Epistomina praetatariensis-Globuligerina parva ‑ in Sudak-Feodosia; zone Anchispirocyclina lusitanica-Melathrokerion spirialis ‑ in Sukhorychensk-Baidar, Demerdzhi-Karabijskaya and Sudak-Feodosiya; the zone of Protopeneroplis ultragranulatus-Siphoninella antiqua in Demerdzhi-Karabijskaya and Sudak-Feodosiya). Characteristic features of each foraminiferа zone include a complex of species, disappearing species, and species that continue to exist, as well as particular features of the complexes. According to lithological peculiarities and paleontological characteristics, suite and sub suite are defined. Conclusions. As a result of the study, the biostratigraphic characteristics of the sections have been specified and the paleontological characteristics of the Upper Jurassic and Lower Cretaceous deposits of the Mountain Crimea have been supplemented.