Calcareous Nannoplankton Zones Research Articles

Nannoplankton Biostratigraphy from Banggai-Sula Basin, Central Sulawesi

The nannoplankton research was conducted in the MH-2 well, Banggai-Sula Basin, Central Sulawesi. Thirty-four ditch-cutting samples were utilized to observe the Minahaki, Kintom, and Biak Formations. Age determination was carried out using biostratigraphy method and standard procedure for first and last occurrence of nannoplankton biodatum and had an absolute age, widely known as a zone indicator. This study aims to determine the age and nannoplankton biozonation of each geological formation in Banggai-Sula Basin. Based on the biostratigraphic analysis, 39 species from 14 genera with abundance frequencies ranging from rare to abundant were found in the MH-2 well. In this study, new results of the age of Banggai-Sula Basin areMiddle Miocene – Early Middle Pliocene (13,706 – 3,727 Ma), and can identify into six calcareous nannoplankton zones that are more detailed than previous researchers, Discoaster signus zone (NN5), Discoaster exilis zone (NN6-NN7), Discoaster berggrenii zone (NN11), Ceratolithus acustus zone (NN12), Helicosphaera sellii zone (NN13-NN15), and the Discoaster tamalis zone (NN16). Biostratigraphic data also shows new information for the first time, the absence of three zones from zone NN8 to zone NN10. This result indicates an unconformity in the Late Miocene age (10.606–8.20 Ma).

NEW INSIGHT INTO THE MIDDLE EOCENE CALCAREOUS NANNOPLANKTON BIOSTRATIGRAPHY AND PALEOENVIRONMENT FROM FAYOUM AND BENI SUEF AREAS, EGYPT

The present study deals with calcareous nannoplankton paleoenvironmental and biostratigraphic implications as well as the genesis and the stratigraphic significance of an event bed recognized from the middle Eocene Beni Suef Formation in the sections of Gebel Na’alun (Fayoum area) and Gebel Homret Shaibun (Beni Suef area), Egypt. Calcareous nannoplankton biostratigraphy indicates that the Beni Suef Formation in the two areas is synchronous, covering an interval that may be correlated with the calcareous nannoplankton Zone NP17. Paleoenvironmental implications from calcareous nannoplankton suggests deposition of sediments in the Beni Suef Formation under relatively stable, temperate and mesotrophic conditions, with a short interval of eutrophication in the basal part of the Homret Shaibun section.

Comments on “Paleoecology and paleobiogeography of Paleocene ostracods in Dineigil area, south western Desert, Egypt.” by Youssef et al., Journal of African Earth Sciences, 131 (2017) 62–70

In their recent paper, Youssef et al. (2017) published a quantitative study of Paleocene ostracod distributions in the Southwestern Desert of Egypt and recognized regional ecozones within a paleobiogeographic concept. To understand the significance of this ecozonation, a solid stratigraphic framework is required, though the authors only provided limited information. We demonstrate that fundamental aspects of their data representation and stratigraphic interpretation are incorrect, and thus not warrant utilization of the reported age of the ostracod record. For that reason, we stress that basic geological aspects of correlation between outcrops and creation of composite sections should be described in full detail upon publication. Based on our detailed reconstruction, the composite sequence at Bir Dungul spans calcareous nannoplankton Zones NP5-NP7/8, and mostly Thanetian in age, contrasting the observations of Youssef et al. (2017). The lowermost part of the sequence, suggested to comprise NP4 by Youssef et al. (2017) and thus Danian in age, cannot be dated because of lack of calcareous nannofossils and planktic foraminifera. Accordingly, there is no evidence in this sequence for the Latest Danian Event (as proposed by Youssef, 2014) either, and the potential relationship with the Mid Paleocene Biotic Event should be assessed critically. Consequently, accurate stratigraphic analysis, including biostratigraphy, remains essential to safeguard future paleobiogeographic interpretations along the edges of the Tethyan Ocean.

Sequence stratigraphy and biozonation of the Upper Eocene Anqabiya Formation, Gebel Anqabiya, Egypt

Few studies on bio-sequence stratigraphy of the late Eocene succession in the study area have published so far. Accordingly, an exposed section of the Anqabiya Formation at Gebel Anqabiya along Cairo–Suez district of Egypt, was examined in detail to determine its foraminiferal and nannoplankton assemblages and to produce a sequence stratigraphic classification. We reveal that in this section, foraminifera and calcareous nannoplankton are generally rare, with relatively poor to moderate preservation, and restricted to certain horizons. Nineteen species of planktonic foraminifera and 24 species of calcareous nannoplankton were identified, leading to the classification of two planktonic foraminiferal zones (Globigerinatheka semiinvoluta Zone E14 and Globigerinatheka index Zone E15) and one calcareous nannoplankton zone (NP19–20). Forty-seven species of benthic foraminifera were identified and quantitatively analyzed to determine changes in paleo-water depth. Three local benthic biofacies, the Elphidium biofacies, the Cibicides biofacies and the Uvigerina biofacies, were recognized, and six microfacies types were distinguished. These analyses indicate that the studied succession was deposited under shallow marine environmental conditions representing a single 3rd-order depositional sequence. The interpreted sea-level curve can be correlated with the global curves during the late Eocene, and the correlation suggests a sea-level rise during E14 Zone, followed by a sea-level fall in E15 zone.

Integrated stratigraphy of the Priabonian (upper Eocene) Urtsadzor section, Armenia

The transition from the Bartonian to the Priabonian, as traditionally understood, has long been associated with a series of extinctions and originations in several microfossil groups. The planktonic foraminifer genus Morozovelloides and large species of Acarinina suffered a rapid global extinction, as did many radiolarians. Calcareous nannofossils show several assemblage changes including the acme beginning of Cribrocentrum erbae and the lowest and highest occurrences of Chiasmolithus oamaruensis and C. grandis respectively. In shallow water environments, larger foraminifera also show an extinction among large species of Nummulites, as well as the first occurrences of the stratigraphically important genus Spiroclypeus. However, the correlation between shallow and deep water records remains uncertain, as do the mechanisms driving these biotic events. Here we present the results of a new integrated stratigraphical study (calcareous nannofossils, planktonic foraminifera, larger benthic foraminifera, and low-resolution magnetostratigraphy) of the Urtsadzor section in south-western Armenia which appears to be continuous through this interval. The Urtsadzor section consists of calcareous siltstones rich in micro- and nannofossils, with interbedded limestones containing abundant larger benthic foraminifera. Our new data enable us to correlate larger foraminiferal events with global plankton biostratigraphy, in a section outside of southwest Europe where most previous correlations have been based. At Urtsadzor, the large Nummulites species of N. millecaput-group are present throughout the whole section but decrease in abundance toward the top. The first occurrence of Spiroclypeus, also occurs in the upper part of the section, marking the SBZ 18/19 boundary. These events are associated with the phylogenetic development of the Nummulites fabianii and Heterostegina reticulata lineages. However, the calcareous plankton biostratigraphy indicates the section is well within the Priabonian; within planktonic foraminiferal Zones E14 and E15 and calcareous nannoplankton Zones CNE 18 and CNE 19. These results indicate larger foraminiferal events occur well above the planktonic foraminiferal extinction level and nannofossil assemblage changes indicating the events are not synchronous across groups, with implications for biostratigraphy and recognition of the basal Priabonian in different depositional settings and regions.

The Campanian–Maastrichtian foraminiferal biostratigraphy of the basement sediments from the southern Pannonian Basin (Vojvodina, northern Serbia): implications for the continuation of the Eastern Vardar and Sava zones

Abstract Micropalaeontological and biostratigraphical studies included Campanian-Maastrichtian complexes from five oil exploration wells drilled in northern Serbia (Vojvodina): the first is a carbonate-clastic complex and second is a complex containing ophiolites intercalated with hemipelagic and pelagic sediments. Within the studied complexes, rich associations of planktonic and benthic foraminifera, calcareous nannoplankton, palynomorphs, as well as shallow and deep-water fossil detritus were determined. The presence of relatively rich associations of planktonic foraminifera allowed recognition of two biozones: the Globotruncana ventricosa Zone, observed in the sediments of the carbonate-clastic complex and the Gansserina gansseri Zone, observed in both complexes. Except biozones, based on documented index species, for some units in both complexes, larger benthic foraminifera species had special biostratigraphical value, and in some of them, the calcareous nannoplankton zones were recognized. The studied complexes represent deep-water formations, generated in oceanic island arc and trough zones. The presence of limestones, which originate from destroyed rudist reefs, is explained by transfer by means of gravitational transport mechanisms of shallow-water sediments to deep-water depositional environments. In this paper, the results of more detailed biostratigraphical and palaeo-ecological studies of foraminifera associations in Campanian-Maastrichtian complexes in Vojvodina are presented. Combined with lithological studies, seven units were determined within the complexes. The obtained results are important as a part of multidisciplinary, regional exploration of both complexes, generated in specific geological conditions, that today constitute a part of the pre-Neogene basement complex in the southeastern part of the Pannonian Basin. The Campanian- Maastrichtian carbonate-clastic complex represents sedimentary cover of the Eastern Vardar Ophiolitic Unit, while the ophiolites intercalated with hemipelagic and pelagic limestones belongs to the Sava Zone.

New bio-chemostratigraphic dating of a unique early Eocene sequence from southern Europe results in precise mammalian biochronological tie-points

European early Eocene (Ypresian) mammalian biochronology, covering a timespan of about 8 myr, includes three distinct MP (Mammal Paleogene) reference levels MP7, MP8+9 and MP10. These are represented in the unique succession of the Minervois (Southern France) by the localities of Fournes (close to MP7), Sainte-Eulalie (close to MP8+9) and Azillanet (close to MP10). Considering homogenous terrestrial organic matter contribution (type III) as suggested by palynofacies and Rock-Eval pyrolysis, we here demonstrate that the organic carbon isotope curve of the predominantly continental Ypresian of the Minervois closely matches the marine standard carbonate carbon isotope curve. The here studied mammalian faunas and their supposed corresponding MP levels can thus be accurately dated and correlated on a global scale. The endemic Fournes mammal fauna, located just above the Eocene Thermal Maximum 2-ETM2, is assigned to mid-Biochron NP11 Calcareous Nannoplankton Zone. Accordingly, the Fournes mammal site is about 2.5 myr younger than the MP7 reference level of Dormaal (Belgium, latest Biochron NP9), about 1 myr younger than the MP7 mammalian locality of Le Clot in the Corbieres (Southern France, late Biochron NP10 or early Biochron NP11) and very close to the Wasatchian Wa-5 mammalian biozone of Wyoming. A mid-Biochron NP12 age is inferred for the endemic Sainte-Eulalie fauna because of its position at the very top of (or just above) the isotopically negative ``ETM3 interval'', whereas the Azillanet fauna, recorded at the top of a delta C-13(org) positive trend above the ``ETM3 interval'', ranges from late Biochron NP12 to early Biochron NP13. Our results indicate that the short-term hyperthermals ETM2 and ETM3 did not affect the endemic character of the mammalian faunas in Southern and Northern Europe during the MP7 to MP8+9 interval. The end of this mammalian endemism likely occurred during the early phases of the EECO (Early Eocene Climatic Optimum) in early late Biochron NP12.

Nouveaux enjeux pour la réhabilitation respiratoire dans la bronchopathie chronique obstructive

The Eocene/Oligocene boundary in Europe is marked by major discontinuities in all environments: the “Grande Coupure” in continental mammals; the elimination of semitropical elements from high-latitude floras; the virtually complete replacement of the shallow-marine malacofauna; and an extraordinary downslope excursion of carbonate deposition in deep-ocean basins (drop in the CCD). These phenomena collectively represent the “Terminal Eocene Event” (TEE). In the Carpathian Mountains, the TEE is manifested in the thin but regionally persistent Globigerina Marl, a calcareous unit containing abundant cool-water microplankton that occurs within very thick, siliceous, bathyal flysch sequences. In southern Poland, the marl is of very latest Eocene age, within planktonic foraminifera zone P17, calcareous nannoplankton zone NP19/20, and the zone of the dinoflagellate Rhomdodinium perforatum. Zircons from bentonites bracketing the marl are dated by fission-track analysis; at Polany, two underlying bentonites are 41.7 and 39.8 Ma, and at Znamirowice two overlying bentonites are 34.6 and 28.9 Ma, in sequence. This accords with glauconite K/Ar ages in Western Europe by which the Eo/Oligocene boundary age is estimated at 37–38 Ma. Global correlations indicate that the TEE corresponds to a major glacio-eustatic regression with a duration of about 0.5 Ma, in which a large Antarctic ice cap was formed, the ocean circulation was permanently changed to the psychrospheric condition, and world climate shifted irreversibly towards the modern state.

Evolution of depositional systems and sedimentary cycles in Želiezovce Depression of the Danube Basin

Five deep wells (Pozba4, Pozba3, Dubnik1, Nova Vieska1, Modrany1), drilled in the Želiezovce depression of the south-east Danube Basin penetrate the Cenozoic sedimentary record in overall thickness ranging from 1000 m up to 3000 m, the total thickness gradually increases from South to the North. This area is well known for the complex geological structure related to the Central Western Carpathians and Transdanubian Range junction along the Hurbanovo – Diosjeno line. Many authors have studied this area in the past, nevertheless Depositional systems, sedimentary cycles and the development of sedimentary facies were never understood in detail. The Re-evaluation of biostratigraphy, paleoecology, sedimentology and the Re-interpretation of e-logs ware all incorporated into well correlations, what resulted in definition of four main sedimentary cycles: (1) The Lowermost Oligocene cycle, consisting of mudstones with occasional sandstone intercalations, associated with slope to offshore marine environment what is supported by the presence of the NP 22 calcareous nannoplankton zone. (2) The transgressive Langhian (Lower Badenian) deposits, composed of mudstones with epiclastic volcanic material and tuffite beds ware associated with shelfall to offshore environement the age is supported by the NN4 - NN5 calcareous nannoplankton zone. (3) The Serravallian (Upper Badenian - Sarmatian) cycle is composed mainly by mudstones with abundant Lithothamnium fragments associated with brackish coastal pain environment, supported by the NN6 calcareous nannoplankton zone and by the mass occurrence of fish scales and Ervilia dissita (Eichwald) bivalves. (4) The overlying strata are represent the Tortonian-Pliocene (Pannonian-Pliocene) cycle, consists mostly from claystone which are overlain by sandstone and siltstones layers is associated with lake, deltaic and alluvial plain environment.

Early Eocene environmental development in the northern Peri-Tethys (Aktulagay, Kazakhstan) based on benthic foraminiferal assemblages and stable isotopes (O, C)

Abstract The Aktulagay section in Kazakhstan provides an expanded northern Tethyan record of the middle Ypresian (calcareous nannoplankton zones NP11–13, ~ 54–50 Ma), including the Early Eocene Climatic Optimum (EECO). The marl sequence features a series of sapropel beds, observed throughout the Peri-Tethys, indicative of the basin-wide occurrence of episodic hypoxic events. In order to unravel the paleoenvironmental evolution at Aktulagay during this period of global warming, we investigated the benthic foraminiferal record by means of a detailed multivariate analysis of the > 63 μm fraction, as well as through stable isotopic (C, O) investigations on excellently preserved benthic foraminiferal specimens. The Alashen Formation (NP11 to lower NP12; ~ 54 to 52.5 Ma), in the lower part of the sequence, contains a diverse assemblage of deep outer neritic (~ 200–250 m) benthic foraminifera, with common Pulsiphonina prima and Paralabamina lunata. The seafloor conditions are interpreted as initially (54 Ma) well-ventilated and oligo- to mesotrophic, gradually changing to more eutrophic and oxygen-limited, culminating in more permanent low oxygen conditions and eutrophy in the sapropel-bearing Aktulagay B1 unit (middle NP12; ~ 52.5-52 Ma). The latter conclusion is corroborated by the dominance of Anomalinoides acutus and Bulimina aksuatica and the lower diversity. Also the upward migration of endobenthic species to the sediment–water interface, as suggested by rising δ13Cendobenthic values, supports this interpretation. A transgression, which flooded lowlands, might have caused this development. In the Aktulagay B2 unit (top NP12–NP13; ~ 52–50 Ma), benthic foraminiferal assemblages dominated by Epistominella minuta suggest an oligotrophic environment, with transient pulses of phytodetritus and moderate ventilation. The Aktulagay B2 unit coincides with the peak temperature interval of the EECO, as indicated by its position close to the base of NP13 and rising δ13Cepibenthic values. Large river plumes, episodically reaching the area, in a monsoonal climatic context, might explain this basin development. Although it is not unlikely that some of the observed patterns are related to long-term climate change, it can currently not be excluded that changing paleogeography and variable connections to the Tethys, Atlantic and the Arctic Ocean were responsible for the long-term period with dysoxia and anoxia during deposition of the sapropel beds at the Peri-Tethyan seafloor. The evolution of the basin as observed in Aktulagay shows similarities to the evolution of the North Sea Basin as observed in Denmark, suggesting that these basins were connected during the Early Eocene.

The basal Lutetian Transgression on the Tethyan shelf of the European craton (Adelholzen beds, Eastern Alps, Germany).

The middle Eocene Adelholzen beds were deposited on the northern part of the Tethyan shelf of the European Plate. In the Eastern Alps, the Wimmern section near Teisendorf (Germany) is the only known outcrop exposing the basal unconformity of this sequence. The outcrop comprises an 8 m thick condensed transgressive shallow marine succession characterized by glauconite-rich weakly consolidated greensand and mudstone containing abundant larger benthic foraminifera. It spans the lower part of calcareous nannoplankton Zone NP15 (Sub-Zones NP15a and lower part of NP15b), planktonic foraminifera Sub-Zone E7b and Zone E8 partim and the upper part of shallow benthic Zone SBZ13. The landward migration of the paleo-shoreline was not an effect of flexural downbending of the European Plate but can be correlated to the major unconformity at the base of eustatic supercycle TA3. The onset of this sea-level rise was in the latest part of Biochron NP14b and almost coincided with the NP14b/NP15a-boundary.

Biostratigraphy and paleoenvironment of the Upper Cretaceous deposits in the northern Tarcău Nappe (Eastern Carpathians) based on foraminifera and calcareous nannoplankton

Abstract Late Cretaceous foraminiferal and calcareous nannoplankton assemblages from the northern part of the Tarcău Nappe, Hangu Formation in the northern Eastern Carpathians are documented in order to reconstruct paleoenvironmental settings and biostratigraphy. The foraminiferal assemblages are dominated by flysch-type agglutinated taxa suggesting bathyal environments, close to the calcite compensation depth (CCD), and mesotrophic to oligotrophic conditions. The morphogroup analyses display variations in tubular and infaunal morphotypes suggesting different levels of oxygenation and seafloor disturbance caused by currents. Reddish hemipelagites containing only agglutinated foraminifera (dominant infaunal forms) occurring in the middle part of the section suggest an increase of water depth and changes in redox conditions. Based on foraminifera, the deposits were assigned to planktonic Globotruncana ventricosa and agglutinated Caudammina gigantea Zones. The first occurrence of Uniplanarius trifidus and last occurrence of Reinhardtites anthophorus demonstrate the presence of Late Campanian UC15cTP-UC16/CC21-CC23 calcareous nannoplankton Zones. Foraminiferal and nannofossil assemblages in the red beds have a high potential for stratigraphic correlation on a regional scale.

Dinoflagellate cysts and palynofacies across the Cretaceous/Palaeogene boundary at the Neritic Waidach Section (Eastern Alps, Austria)

In this study, dinoflagellate cyst and calcareous nannoplankton biostratigraphy allowed the recognition of the Cretaceous/Palaeogene boundary (K/Pg boundary) at the neritic Waidach section, north of Salzburg, Austria (Helvetic nappe system). The microfossil assemblages indicate calcareous nannoplankton Zone CC26 of latest Cretaceous age and part of the lowermost Palaeocene Zone NP1. However, the stratigraphic record across the K/Pg boundary is incomplete due to a minor fault. The studied samples have yielded well preserved and high diversity dinoflagellate cyst assemblages with a total of 163 dinoflagellate cyst species and subspecies belonging to 62 genera. The composition of the dinoflagellate cyst assemblages changes drastically from Areoligera-dominated assemblages in the upper Maastrichtian to Hystrichosphaeridium-dominated assemblages in the lower Danian. This composition shows two Manumiella spikes in the upper Maastrichtian and an acme of Spongodinium delitiense in the lower Danian which are interpreted to reflect slight coolings of oceanic surface waters. The earliest Danian markers Carpatella cornuta, Senoniasphaera inornata and Damassadinium californicum have their first occurrences immediately above the K/Pg boundary. The peridinioid/gonyaulacoid (P/G) ratio of most samples suggests high paleoproductivity. Two palynofacies assemblages were distinguished indicating shelf to basin transitions and dysoxic to anoxic conditions.

Maastrichtian to Paleocene dinocysts from the Clarence Valley, South Island, New Zealand

A palynological study of uppermost Maastrichtian to lower Paleocene marine strata from two stratigraphic sections in the Clarence Valley, Marlborough, New Zealand, revealed diverse organic-walled dinoflagellate cyst (dinocyst) assemblages. One hundred and twelve samples were investigated and 86 dinocyst species were identified, from the two sections studied: Branch and Mead streams. Nine new species are described herein: Cerodinium nielsii, Impagidinium agremon, I. cavea, I. crouchiae, I. hannahii, Lejeunecysta kammae, Pyxidinopsis epakros, P. everriculum and P. meadensis. Stratigraphic correlations are achieved using nine new index species and eight cyst acme intervals, named A to H, integrated with foraminiferal datums and the radiolarian zonation for the South Pacific. The first occurrence of Carpatella septata combined with a high relative abundance of Diconidinium martianum characterizes the interval directly below the Cretaceous–Paleogene (K–Pg) boundary or uppermost part of the Manumiella druggii Zone. Based on the results from both sections, the earliest Paleocene Trithyrodinium evittii Zone is subdivided into the following intervals: Senoniasphaera inornata, Carpatella cornuta, Cassidium fragile and Cerodinium striatum subzones. The following dinocyst species first appear at or near the top of the T. evittii Zone: Alterbidinium pentaradiatum, Glaphyrocysta perforata, Habibacysta sp. cf. H. tectata, Kallosphaeridium brevibarbatum, Lejeunecysta kammae, Pyxidinopsis sp. cf. P. waipawaensis, Spiniferella cornuta and Tectatodinium meandriforme. The boundary between the T. evittii and the overlying Palaeocystodinium golzowense Zone was recorded only in the Mead Stream section where it is dated to ca 64.0 Ma. A high relative abundance of Isabelidinium cingulatum succeeded by the first occurrence of Isabelidinium bakeri, Deflandrea foveolata and D. delineata characterizes the lower to middle part of the early Paleocene P. golzowense Zone. The last consistent occurrence of P. pyrophorum is recorded within the upper part of radiolarian Zone RP3 corresponding to the middle part of the early Paleocene calcareous nannoplankton Zone NP3 (Early Teurian) or ca 63.7 Ma. The K–Pg boundary is not characterized by a mass extinction of dinoflagellates in the New Zealand sections. Instead, there is a marked change in cyst associations directly above the boundary and several new species appear in the lowermost Paleocene. Several typical latest Maastrichtian taxa have their last occurrences within the lowermost Paleocene corresponding to an interval of ca 0.5–0.7 Myrs after the K–Pg boundary.

From shelf to abyss: Record of the Paleocene/Eocene-boundary in the Eastern Alps (Austria)

In the Eastern Alps (Austria) several marine successions, which were deposited ranging from shallow shelf to bathyal slope and abyssal basin, provide detailed records across the Paleocene/Eocene-boundary. These records indicate a two-step event starting with a prominent sea-level fall and followed by climatic changes. At the northern and southern shelves that fringed the Penninic Basin, the shallow-water sedimentary records are incomplete across the Paleocene/Eocene transition. Erosional surfaces indicate a major sea-level drop, which was terminated by an early Eocene (Ypresian) transgression within calcareous nannoplankton Zone NP12. As a proxy for the onset of this sea-level fall a strong increase in the terrestrially-derived input into the Penninic Basin can be used. The abyssal Anthering section from the northern part of the basin comprises a complete succession from NP9 to the upper part of NP10 (upper Thanetian-lower Ypresian). The thickest turbidite beds of this 250 m thick succession appear just before the carbon isotope event in the upper part of zone NP9, which is used to recognize the Paleocene/Eocene-boundary. A major lithological change from a sandstone-dominated facies to a claystone-dominated facies occurs at the onset of the carbon isotope event. This might be the result of a climatic change, resulting in increased intra-annual humidity gradients and increased physical erosion of the hinterland. Consequently, mainly fine-grained suspended material would have come into the basin and caused an increase in hemipelagic sedimentation rates by about a factor of 6. A similar value has been calculated for the bathyal Untersberg section, which was deposited on the southern slope of the basin, where an increased input of siliciclastic material is associated with a carbonate dissolution event during the carbon isotope event. At the southern shelf, a stratigraphic gap within the Gosau Group in the Krappfeld area (Carinthia) comprises the Maastrichtian and Paleocene. After a sea-level rise nummulitic marlstone and limestone were deposited in the lower part of zone NP12. Since the northern and southern shelves of the Penninic Basin belonged to different tectonic domains, with different potentials of crustal subsidence, the temporal similarity of sea-level changes on both shelves in the latest Paleocene and earliest Eocene suggests that these sea level fluctuations were mainly eustatic in origin.

Late Maastrichtian - early Paleocene sea level and climate changes in the Antioch Church Core (Alabama, Gulf of Mexico margin, USA): a multi-proxy approach

The Antioch Church core from central Alabama, spanning the Cretaceous-Paleogene (K-P) boundary, was investigated by a multi-proxy approach to study paleoenvironmental and sea level changes within the wellconstrained sequence stratigraphic setting of the Gulf of Mexico margin. The Antioch Church core comprises the Maastrichtian calcareous nannoplankton Zone CC25 and the Danian Zones NP1 to NP4 corresponding to the Maastrichtian planktonic foraminifera Zones CF3 and the Danian Zones P1a to P2. Facies shifts from a Maastrichtian siliciclastic to a mixed siliciclastic-carbonate depositional system during the late Danian. Sedimentary proxies indicate that depositional settings changed between littoral (foreshore) and inner and middle neritic (offshore transition zone). Four sedimentary sequences, each encompassing LST, TST, and HST were identified. Estimated water depths by using benthic foraminiferal assemblages were not exceeding 20-40 m for the Maastrichtian and 0-40 m for the Danian sequences. The succession of facies shifts within systems tracts can be very well disentangled by major and trace element data as well as by various element ratios including Zr/Rb, (Zr+Rb)/Ca, and Sr/Ca. By applying element stratigraphy, the ambiguities of the natural gamma ray log –with peaks associated either with maximum flooding surfaces or with silty lag deposits (“placer silts”) during the late regressive HST– are resolved. In addition, the Zr/Rb ratio provides a good proxy for monitoring grain size distribution and sorting effects. According to the Antioch Church core data, the K-P boundary is associated with a sandstone event bed that includes ejecta spherules from the Chicxulub impact. However, the genesis of the K-P event bed, whether lowstand, tempestite- or tsunami-related, cannot be resolved from this core. In terms of clay mineralogy, the studied interval is characterized by a steady increase in smectite that parallels a decrease in kaolinite with the latter disappearing about two My after the K-P boundary during Biozone NP2. This change in the clay mineral assemblage, which is almost independent of lithology, may suggest a long-term shift from stable, tropical warm and humid climates during the latest Maastrichtian to warm climate with alternating humid and arid seasons in the middle Danian.

Stratigraphy and sedimentation rates of Upper Cretaceous deep-water systems of the Rhenodanubian Group (Eastern Alps, Germany)

In the Bavarian Alps (Germany), west of the Isar River, the abyssal deposits of the Lower Barremian to Upper Campanian Rhenodanubian Group consist of siliciclastic and calcareous turbidites alternating with hemipelagic non-calcareous mudstones. The up to 1500-m-thick succession, deposited in the Penninic Basin to the south of the European Plate, is characterized by a low mean sedimentation rate (c. 25 mm kyr −1) over 60 million years. Palaeocurrents and turbidite facies distribution patterns suggest that sedimentation occurred on a weakly inclined abyssal plain. The highest sedimentation rates (up to 240 mm kyr −1) were associated with the calcareous mud turbidites of the newly defined Röthenbach Subgroup, which includes the Piesenkopf, Kalkgraben and Hällritz formations (Middle Coniacian to Middle Campanian). These calcareous turbidites prograded from the west, and interfinger towards the east with red hemipelagic claystone. A high sea level presumably favoured pelagic carbonate production and accumulation on the shelves and on internal platforms in the western part of the basin, whereas siliciclastic shelves with steep slope angles have bordered the eastern part of the basin, where a dearth of turbidite sedimentation and increased Cretaceous oceanic red beds deposition occurred. In contrast to the eustatically-induced Middle Coniacian to Lower Campanian Cretaceous oceanic red beds (calcareous nannoplankton zones CC14 to CC18), red hemipelagites of Early Cenomanian age (upper part of calcareous nannoplankton zone CC9) and early Late Campanian age (upper part of zone CC21 and zone CC22) are interpreted as the result of regional tectonic activity.

Danian/Selandian boundary stratigraphy, paleoenvironment and Ostracoda from Sidi Nasseur, Tunisia

Two detailed records (NSF and 05NSC, Sidi Nasseur, Tunisia) across the Danian/Selandian (D/S) boundary were investigated for their micropaleontological content. Calcareous nannofossils and planktic foraminifera provided a biostratigraphic framework. The interval spans part of planktic foraminiferal Zone P2, Subzone P3a and part of Subzone P3b. This corresponds to calcareous nannoplankton Zone NP4. Using a more detailed nannofossil zonation the studied section spans part of Zone NTp6, Zone NTp7a and part of NTp7b. Quantitative ostracod and qualitative benthic foraminiferal data were used to characterize environmental changes across the D/S boundary. The two subsections have yielded a total of 50 ostracod taxa. The ostracod assemblage of the entire section belongs to the Southern Tethyan Type showing subtle but distinct changes up section. Based on statistical analysis of the quantitative ostracod data, faunal changes at a glauconitic maker bed (P3a/P3b boundary) were demonstrated. The local Reticulina proteros assemblage, with the typical species R. proteros, Oertliella vesiculosa and Cytheroptheron lekefense, is gradually replaced by the Protobuntonia nakkadii assemblage, with the typical species Cristaeleberis arabii, Xestoleberis tunisiensis, Cytheropteron sp. and P. nakkadii, across the glauconitic bed. The benthic foraminifera also demonstrated distinct changes at this marker bed. The changes in ostracods and foraminifera are related to changes in paleoproductivity and an overall relative sea-level fall. The lithological and faunal changes at the P3a/P3b zone boundary within the Sidi Nasseur sections seem to correspond to the D/S boundary in the type region in Danmark and are characterized by a significant hiatus, yielding this section not suitable as a GSSP candidate for this boundary.

Pleistocene–Holocene calcareous nannofossil biostratigraphy of core samples from The Northeastern Sea of Marmara, Fenerbahçe–Pendik, NW Turkey

Pseudoemiliana lacunosa, Gephyrocapsa oceanica and Emiliania huxleyi (Ionian) (Pleistocene–Holocene) calcareous nannoplankton zones were identified from 82 samples of 14 cores taken from 8 locations in the northeastern Sea of Marmara. The investigation indicates that the identified biozones have been alternated by tectonic activity in the 1, 5 and 6 core locations. The study area has been affected three times by tectonic activity during the Pleistocene–Holocene time interval. The first activity occured during the Early Pleistocene and the others during Holocene.

Early Eocene climatic, volcanic, and biotic events in the northwestern Tethyan Untersberg section, Austria

The 40 m thick Untersberg section (Salzburg, Austria) of the Northern Calcareous Alps comprises the Palaeocene–Eocene transition and spans the upper part of calcareous nannoplankton zone NP9 and the lower part of zone NP10 (sub-zone NP10a). These zones are equivalent to planktonic foraminifera zone P5 and the lower part of zone P6 (sub-zone P6a). The succession was deposited in a lower bathyal slope environment at a palaeodepth of about 2000 m. Within the dominantly marlstone succession, a 5.5-m-thick intercalation of red and green claystone and marly claystone represents the global negative carbon isotope excursion (CIE) which is used to recognize the Palaeocene–Eocene boundary. The CIE was associated with a shallowing of the calcite compensation depth by at least 1 km. Throughout the section, clay mineral assemblages are dominated by smectite, indicating a seasonal climate with alternating wet and dry conditions. A 49% increase in detrital quartz and feldspar within the CIE-interval suggests enhanced continental run-off. This was probably the result of the establishment of a monsoonal setting, in which vegetation was sparse, while periodic high rainfall caused pronounced sediment transport. The increased terrestrially derived input is associated with abundant radiolarian casts indicating high primary productivity. This suggests that seasonal nutrient pulses resulting from intensified precipitation during the wet season have caused high surface-water fertility. The benthic foraminifera faunas of the samples rich in siliceous plankton are strongly dominated by Glomospira spp., Nuttalides truempyii, Abyssamina poagi, Anomalinoides praeacutus, Anomalinoides nobilis, and Oridorsalis spp. We assume that the Glomospira–Nuttalides fauna consists of opportunistic species which quickly react to seasonally varying amounts of food. The calcareous nannoplankton assemblage of the CIE-interval is characterized by the first occurrences of the genus Rhomboaster and of Discoaster araneus and Discoaster mahmoudii, whereas Scapholithus apertus become extinct at the Palaeocene–Eocene boundary . Within nannoplankton sub-zone NP10a, a series of primarily basaltic ashes give evidence for a major episode of explosive volcanism which can be correlated with the positive ash-series of the Fur-Formation in northern Denmark. The wide dispersal distance of the tephras implies Plinian-scale eruptions and multiple ejections of large volumes of pyroclastic material.