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The Badenian/Sarmatian boundary in the Central Paratethys has been traditionally identified by the faunal turnover recording an important environmental change possibly controlled by the change from marine to brackish conditions. The strata below the Badenian/Sarmatian boundary in the northern Carpathian Foredeep are included into the Pecten beds, and those above it into the Syndesmya beds. Foraminiferal study of the Babczyn 2 borehole which is one of the crucial sections in the northern Carpathian Foredeep, well-known for the depositional age of rhyolite tuff within the Pecten beds dated by Śliwinski et al. (2012) at 13.06 ±0.11 Ma, indicated that in fact the boundary occurs within the Syndesmya beds. This conclusion is based upon the rapid change from a stenohaline foraminiferal fauna to a euryhaline one, and the appearance of the species Anomalinoides dividens , the taxon regarded as the marker for the Sarmatian. In the Babczyn 2 and Cieszanow 1 (located ~2.5 km basinward of Babczyn 2) boreholes, Anomalinoides dividens appears 3.1–3.8 m above the replacement of stenohaline by euryhaline foraminifers. The calcareous nannoplankton study shows that the upper Badenian and the lower Sarmatian strata in the studied sections represent the NN6, undivided NN6-NN7, and NN7 zones.

The taxonomy of Late Cretaceous genus Bolivinoides is revised on the basis of rich, newly collected material from central and eastern Poland and western Ukraine. Twelve species are described of which one is new: Bolivinides intermedius nov. sp. This species differs from the other bolivinoidid taxa in possessing two parallel medial rows of tubercles. The stratigraphic ranges of most of the taxa are compared with the macrofossil standard zonation, which allowed a correlation with the occurrence of bolivinoidids of distinct regions of Europe and other continents. The evolutionary trends of Bolivinoides are also discussed and two distinct lineages, Bolivinoides strigillatus and Bolivinoides laevigatus, are distinguished.

The Badenian section of Anadoly near Kamyanets Podilskyy (Ukrainian Carpathian Foredeep Basin) consists of the Tyras Fm. (gypsum and Ratyn Limestone) and the Ternopil Mb. of the Kosiv Fm. The latter are 5.3 m thick and are composed of dark grey mudstones with limestone intercalations. This study indicates the occurrence of over 54 species of benthic foraminifers and 10 species of planktonics. Benthic foraminifera are represented mainly by calcareous forms; agglutinated tests are very rare. Planktonic foraminifera appear in the upper part of the succession studied. Five benthic foraminiferal assemblages are recognized: A ( Elphidium / Lobatula / Astrononion ) B (Hauerinidae), C ( Cibicidoides / Lobatula ), D ( Porosononion ) and E ( Uvigerina / Bulimina ). The foraminiferal record indicates deposition in a shallow subtidal environment (20 m depth) of normal marine salinity and temperate waters followed by gradual deepening of the basin to >50 m. Analysis of foraminiferal assemblages indicates that bottom waters were highly oxygenated during deposition of the lower and middle parts of the Anadoly sequence. During deposition of the upper part of the sequence the oxygenation of bottom water gradually decreased, as expressed by a large decrease in the proportion of oxic species and an increase in dysoxic ones. The same set of samples yielded low amounts of palynological organic matter represented by dominant black opaque phytoclasts; bisaccate pollen grains and dinoflagellate cysts are rare. Taxonomically impoverished assemblages of the latter consist of dominant Polysphaeridium and Cleistosphaeridium placacanthum associated with Lingulodinium machaerophorum and a few other taxa. The taxonomically richest assemblage was found in the topmost sample. These changes were interpreted as indicative for increased salinity in the surface water layer, with its maximum in the middle part of the section; the assemblage from the topmost part is characteristic for normal marine salinity.

Planktonic and benthic foraminiferal assemblages, oxygen stable isotopes, calcium carbonate content and total sulfur and magnetic susceptibility have been studied from the middle Coniacian to middle Santonian interval of the Dubivtsi succession (western Ukraine). At the Coniacian–Santonian boundary significant changes took place in foraminiferal assemblages. Keeled, deep-water forms, which are a common to dominant group in planktonic foraminiferal assemblages in the late Coniacian decline in abundance in the Santonian, where the assemblages are dominated by heterohelicids and Hedbergella. Late Coniacian benthic foraminiferal assemblages dominated by large, calcareous epifaunal (oxic) forms in the early Santonian became dominated by small, thin-walled, infaunal (dysoxic) species with significant increase of agglutinated foraminifers within assemblages. Changes in foraminiferal assemblages correspond with lithological changes from upper Coniacian limestones to lower Santonian marls. An increase in total sulfur in the lower Santonian and increase in magnetic successibility values up the succession are recorded. Changes in foraminiferal assemblages along with decreasing calcium carbonate content and increasing magnetic susceptibility indicate that during the early and middle Santonian the Tethyan connection with the studied part of the south-central European epicontinental sea was partially limited by an area uplifted as a consequence of Subhercynian tectonic movements; thus it constituted a partially restricted basin with sedimentation in an oxygen depleted environment.

This paper discusses the classification and evolutionary trends of the late Turonian-early Campanian genera Gavelinella and Stensioeina from western Ukraine, including the definition of five Gavelinella lineages ( G. ammonoides, G. stelligera, G. vombensis, G. pertusa , and G. clementiana ) and two Stensioeina lineages (S . exsculpta and S . perfecta ). The latter two differ from each other in test shape, umbilical arrangement, and stratigraphic ranges. Older forms of S. exsculpta possess an umbilicus partially covered by triangular flaps extending from the umbilical parts of the chambers (type-X ornamentation), whereas the umbilicus in younger forms is partially covered by undulating outgrowths extending from the surface of the test (type-Y ornamentation). Changes in the Stensioeina perfecta lineage include an increased test thickness and an umbilical area characterized by widening and joining of chamber flaps into an umbilical plug. Protostensioeina n. gen. is proposed to accommodate species characterized by the lack of features typically observed in Stensioeina , such as spiral-side ornamentation consisting of curved, limbate sutures, strongly elevated in somewhat irregular, curly ridges, resulting in a reticulose surface and a sharp, angular border.

Benthic and planktonic foraminifera from a marly clay intercalation sandwiched between mid-Badenian (Middle Miocene) gypsum deposited in an environment of an evaporitic shoal (

The interval studied comprises a 45-m-thick section of uppermost Coniacian and lower Santonian strata. More than 30 planktonic foraminiferal species were recorded. The following sequence of bioevents is recorded from bottom to top: (1) FO of Sigalia carpatica; (2) FO of Costellagerina pilula; (3) FO of typical “pill-box-like” morphotypes of Globotruncana linneiana. The planktonic foraminifera allow the subdivision of the section studied into two heterohelicid zones: Pseudotextularia nuttalli and Sigalia carpatica, and the correlation of the zonal boundary with the inoceramid scheme. The Coniacian/Santonian boundary, as defined by the first occurrence of Platyceramus undulatoplicatus (Roemer), falls in the lower part of the Sigalia carpatica Zone. FOs of Costellagerina pilula and typical “pill-box-like” morphotypes of Globotruncana linneiana are a good proxy for the stage boundary.

The Upper Campanian–Lower Maastrichtian interval of the Middle Vistula River Valley section records the following benthic foraminiferal bioevents in ascending stratigraphical order: LO of Globorotalites michelinianus, FO and LO of Globorotalites emdyensis ( =G. hiltermanni ) , FO of Bolivina incrassata, FO of Bolivinoides miliaris, FO of Angulogavelinella gracilis ( =A. bettenstaedti ) , LO of Gavelinella monterelensis, FO of Osangularia navarroana, FO of Bolivina decurrens and FO of Neoflabellina reticulata . These events are recorded in very similar stratigraphic positions in the Lagerdorf-Kronsmoor succession (northern Germany) and in the succession of eastern England and, at least some of them, in eastern Europe. Accordingly they can serve as important markers for stratigraphic correlation across Europe. The FOs of the planktonic species, Rugoglobigerina milamensis, R. hexacamerata and R. pennyi , in the uppermost part of the “ Inoceramus” redbirdensis Zone,are very close to the Campanian–Maastrichtian boundary as defined by inoceramid bivalves (Walaszczyk, 2004) and we propose these planktonic foraminiferal bioevents as a good proxy for this boundary in temperate regions.

The Cenomanian‐Turonian succession of faunal assemblages identified in Sakhalin has enabled the establishment of 10 ammonite, 7 inoceramid, 4 radiolarian, and 2 foraminiferal zones, which correlate relatively well with those recorded for the northeastern region of Russia (Kamchatka and Koryakia) and for Japan. The problems surrounding placement of the Cenomanian/Turonian boundary in Sakhalin and in adjacent areas are reviewed. Significant macrofaunal turnover and radiation have been identified across the (locally defined) Cenomanian/Turonian boundary, as well as in the middle Turonian for ammonites and in the upper Turonian for inoceramids. The first occurrences of the widely distributed Pacific ammonite Jimboiceras planulatiforme (Jimbo), the cosmopolitan ammonite Fagesia, and the inoceramid Mytiloides aff. labiatus (Schlotheim), define the base of the Turonian Stage. The succession of foraminiferal assemblages does not exhibit any major extinction at the Cenomanian/Turonian boundary; however, a...

Benthic foraminiferal assemblages, in contrast to planktic foraminifera, generally did not suffer mass extinctions at the Cretaceous/Palaeogene (K/P) boundary; extinctions were fewer in deeper water. However, the outer shelf, upper bathyal section at Ain Settara, Tunisia, records a dramatic change in the structure of benthic foraminiferal assemblages across the K/P boundary. At the level of extinction of planktic assemblages and enrichment in Ir and other geochemical anomalies, highly diversified, low-dominance Upper Maastrichtian assemblages with infaunal and epifaunal morphogroups were suddenly replaced by taxonomically impoverished assemblages, strongly dominated by epifaunal morphogroups. This extinction or temporary emigration of most infaunal morphogroups is interpreted to be the result of a sudden breakdown in food supply. This, in turn, is the consequence of a sudden collapse in primary productivity, probably resulting from the impact of the K/P asteroid.

An Upper Cenomanian to Lower Turonian section has been sampled in the vicinity of Ganuza, northern Spain. Ammonoids, inoceramids and microfossils including foraminifera and calcareous nannofossils have been studied. We recognize three planktonic foraminiferal biozones: theRotalipora cushmani,Whiteinella archaeocretaceaandHelvetoglobotruncana helveticaZones. We also characterize theEiffellithus turriseiffeliiandQuadrum gartneriZones, based on nannofossil biostratigraphy. Macrofaunal occurrences are scarce but allow us to characterize theMetoicoceras geslinianumandMammites nodosoidesZones, and two inoceramid assemblages. In theRotalipora cushmaniZone the following sequence of biohorizons is recorded from bottom to top: (a) last occurrence (LO) ofCorollithion kennedyi; (b) LO ofRotalipora greenhornensis; (c) LO ofAxopodorhabdusalbianus; (d) first occurrence (FO) ofEuomphaloceras septemseriatum, (e) LO ofLithraphidites acutus; (f) LO ofRotalipora cushmani. In theWhiteinella archaeocretaceaZone the sequence of events is as follows: (g) FO ofCalycoceras naviculare; (h) LO ofMicrostauruschiastius; (i) FO ofQuadrum intermedium; (j) FO ofHelvetoglobotruncana praehelvetica; (k) FOs ofKamerunocerassp. andMytiloidessubmytiloides; (l) FO ofMytiloides kossmati kossmati; (m) FO ofKamerunoceras calvertense; (n) FO ofQuadrum gartneri; (o) FO ofMammites nodosoides; (p) FO ofMytiloides mytiloides. The top of this zone is marked by the FO ofHelvetoglobotruncana helvetica.A possible Cenomanian-Turonian (C/T) boundary can be drawn between FOs ofKamerunocerassp. andMytiloidessubmytiloidesand the FO ofMytiloides kossmati kossmati. Successive FOs ofH. praehelveticaandQ. gartneriare also good proxies for the C/T boundary.

The Lechowka section comprises the most complete Cretaceous–Paleogene (K-Pg) boundary succession in Poland and is among 29 sites worldwide with the youngest ammonite record. Here, cephalopods (ammonites and nautilids), organic-walled dinoflagellates (dinocysts) and foraminifera from the uppermost Maastrichtian interval are studied. In terms of ammonite biostratigraphy, the upper Maastrichtian Hoploscaphites constrictus crassus Zone is documented up to a level 120 cm below the K-Pg boundary. There is no direct, ammonite-based evidence of the highest Maastrichtian H . constrictus johnjagti Zone. However, the predominance of the dinocyst marker taxon Palynodinium grallator suggests the presence of the equivalent of the uppermost Maastrichtian Thalassiphora pelagica Subzone, which is correlatable with the H. c. johnjagti ammonite Zone. The planktonic foraminiferal assemblage is coeval with that from the H. c. johnjagti Zone as well. These data indicate that the top of the Maastrichtian at Lechowka is complete within the limits of biostratigraphic resolution, albeit slightly condensed. The dinocyst and foraminiferal assemblages are dominated by taxa that are characteristic of high-energy, marginal marine environments. A reduction in test size among the calcareous epifaunal benthic foraminifera is observed at a level 50 cm below the K-Pg boundary, which is possibly related to environmental stress associated with Deccan volcanism.

Two sections of the Upper Cenomanian and Lower Turonian in central and south-east Poland were investigated for foraminifers, CaCO3content, carbon content insoluble in HCl (Corg) and in the carbonates (Ccarb), carbon and oxygen isotopic composition of bulk-rock carbonates and elemental abundances. The Cenomanian/Turonian boundary interval is characterized by the appearance of more marly facies, a δ13C and δ18O stable isotope anomaly, a considerable increase in Corg content and decrease in Ccarb content and substantial changes in the foraminiferal assemblages. A major carbon stable isotope excursion with a shift of +2 (PDB) occurs in the lowermost Whiteinella archaeocretacea Zone. The late Cenomanian δ13C anomaly is associated with heavy δ18O values. The peak value of δ13C corresponds to the minima in P/B ratio and in diversity of foraminiferal assemblages. A late Cenomanian anoxic event is thought to be responsible for changes in foraminiferal assemblages. However, elemental abundance analyses do not show changes in the concentrations of trace elements. This may be explained by the long distance between studied area and a source of enrichment which was probably located in the western hemisphere.

Prolonged dysaerobic conditions probably caused the extinctions recorded within many of the late Cenomanian marine benthonic foraminiferal community. The surviving low diversity assemblage contains morphotypic associations that may be recognised over a wide geographical area. Environmental pressure selected for low oxygen tolerant infaunal forms and others that could readily adapt to this mode of life. The recolonisation by the benthonic foraminifera was very slow, in the western Anglo‐Paris Basin and in the southeast Danish‐Polish Trough, in contrast to the planktonic foraminifera. This may be a result of several influences: low migration rates of benthonic foraminifera, appreciably deeper water, the persistance of oxygen‐poor water at depth and/or changes in substrate induced by the radically different Turonian carbonate facies.

Stable isotopes (13C, 18O), CaCO3 contents, carbon content insoluble in HCl (Corg) and in the carbonates (Ccarb), and foraminifers have been investigated in the Cenomanian-Turonian boundary interval (uppermost Rotalipora cushmani Zone and lower Whiteinella archaeocretacea Zone) in SE Poland. The stage boundary is defined by the appearance of the coccolith species Quadrum gartneri Prins & Perch-Nielsen. The higher content of Corg in the uppermost Rotalipora cushmani Zone and lowermost Whiteinella archaeocretacea Zone, a δ 13C and δ 18O stable isotope anomaly in the uppermost Cenomanian, and substantial changes in the foraminiferal assemblages have been recorded. A major carbon stable isotope excursion with a shift of up to +2.0‰ δ 13C (PDB) is located a short distance above the Rotalipora cushmani-Whiteinella archaeocretacea boundary within marly limestones. The peak value of δ 13C corresponds to the minimum P/B ratio, and minima in the diversity and abundance of foraminiferal assemblages. A late Cenomanian expanding mid-water oxygen minimum zone is thought to be responsible for changes in foraminiferal assemblages in the uppermost Rotalipora cushmani and lower Whiteinella archaeocretacea Zones.

The studied interval extends from 2.5 m below to 1 m above the Cretaceous/Paleogene (K/P) boundary and comprises the uppermost Maastrichtian marly limestone overlain by a boundary (rusty) layer—a dark yellow orange clay 5–10 mm thick, followed by a turbidite sequence of very fine sandstones and grey-brown marls. The following planktonic foraminiferal zones are distinguished: Abathompalus mayaroensis, PO (subzones: POa— Guembelitria cretacea and POb — Globoconusa conusa), Pa or Parvularugoglobigerina eugubina and P1 (subzone: P1a or Subbotina pseudobulloides). The distribution of iridium shows a relatively sharp rise to a maximum value of 7.176 ppb about 1.2 cm above the rusty layer, followed by a rapid drop to normal background levels. The Abathomphalus mayaroensis Zone exhibits a moderately diverse planktonic foraminiferal assemblage. The main extinction episode occurs within the rusty layer; only a few species survived. Survivors are small primitive forms. The first new Paleocene species evolved immediately after the major Cretaceous extinctions. Rapid extinction of planktonic foraminifers coincides with the iridium anomaly which suggests that, at this site, the source(s) of the iridium anomaly was (were) probably responsible for K/P extinctions.

Algal oncolites are regarded as indicators of shallow-water environment and the size of oncolitic forms is often regarded as an indication of turbulence: the bigger the forms, the stronger the turbulence assumed. Similar environmental significance is also usually ascribed to foraminiferal-algal oncolites. The well-known example of foraminiferal-algal oncolite is Osagia, which was ascertained by Johnson (1946, p. 1103) as being composed of intergrown blue-green algae (Porostromata) and encrusting foraminifera. Osagia is often regarded as environmental index fossil and clear, shallow (0–10 feet), warm, gently agitated water is assumed. There is no doubt that such interpretation is an overgeneralization. This is shown by two other examples of foraminiferal-algal oncolites: soft delicate “tender” oncolites from the Zechstein Limestone (Upper Permian) and Sphaerocodium from the Alpine Triassic.

The widespread expansion of the oxygen minimum zone onto shelves has been commonly regarded as a primary cause of benthos extinction in epicratonic sea ecosystems during the Cenomanian–Turonian boundary event (CTBE). However, neither lithology, geochemical proxies, nor micropaleontological data support this hypothesis. Instead, our integrated foraminiferal and dinoflagellate cyst study, corroborated by δ13Corg and δ15Norg data, indicate that the biota were impacted by an abrupt shift to well oxygenated oligotrophic conditions and a collapse of primary productivity in the epicontinental Central European Basin. Because the event was concurrent with the development of extensive and extreme oceanic bottom water anoxia that reached the photic zone in oceanic settings, we infer that the biotic crisis in the shelf seas during OAE2, and possibly during other OAEs, was triggered by this anomalous nutrient cycling in Earth’s oceans. This phenomenon was presumably associated with intensive denitrification combined with anammox activity in the deep ”ammonium oceans”, which caused a significant loss of biologically reactive nitrogen from the ocean system. Impingement of ammonium-rich anoxic waters on the photic zone resulted in primary productivity based primarily on ammonium assimilation, as recorded by strongly 15N-depleted organic matter deposited in the oceans during the CTBE. We propose that, unlike in the oceanic settings, productivity in the well-oxygenated, oligotrophic epicontinental seas was nitrate-based, as evidenced by strongly 15N-enriched organic matter deposited in the contemporaneous epicontinental sea. These very high δ15Norg values (> +5‰) were related to the spreading of shallow oceanic waters carrying 15N-enriched nitrate onto epicontinental settings.