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High-resolution A, and low-resolution B, abundance patterns of Species A. The aliasing effect is particularly evident in the lowresolution data set where the signal is completely distorted by the loss of information. The sampling resolution is of 10 cm in A and of 100 cm in B. Biohorizons are positioned at the mid-points.
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Calcareous nannofossils are considered one of the most powerful biostratigraphical tool in marine carbonate sediments especially in open ocean settings. Their origination goes at least as far back as the Triassic (ca. 220 Ma) when they first biomineralized and produced calcite skeletons. Since then, they have evolved rapidly showing widespread biog...
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... low-resolution data could be affected by profound distortions of the real data due to the serious loss of information. An example of the aliasing effect is reported in Figure 5, where low- resolution and high-resolution abundance patterns of an idealized species A are compared. The positions of the Base and Top of species A show remarkable differences that would eventually result in inconsis- tent biostratigraphical data. ...
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Calcareous nannofossils are < 30 µm sized calcitic fossil remains of single-celled marine photoautotrophic algae. Carbonate-rich sedimentary rocks, containing these fossils, are used as raw material for lime-based mortars. The carbonates (CaCO3) are heated up to approx. 900 °C. The burning process, which causes the thermal decomposition of CaCO3 in...
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... Therefore, we were interested in examining the Eocene/Oligocene boundary based on calcareous nannofossil assemblages in the Jeneponto area. High-resolution biostratigraphy with nannofossils can provide the ages of rocks with higher precision and is one of the most powerful biostratigraphical tools in carbonate sediments (Agnini et al. 2017). This applies also to the investigation of the paleoenvironment, paleoclimate, paleoceanography, and other aspects (Perch-Nielsen 1985;Persico and Villa 2004;De Vargas et al. 2007;Villa et al. 2008;Ali 2009;Sato and Chiyonobu 2009). ...
The biostratigraphy of the Tonasa Formation in the Jeneponto Regency of South Sulawesi, Indonesia, is still poorly known, and there are barren ages, such as much of the Oligocene to Early Miocene. The Tonasa Formation is well exposed along the coast of the Jeneponto Regency, in which the Karama area consists of the most important outcrops of this formation which in this area consists of interbedded marl and limestone. Our study focuses on the biostratigraphy of the Karama area section A based on nannofossil. Samples were collected by measured stratigraphy methods and then subjected to investigation using smear slides. The assemblages of species were determined by semiquantitative analysis. Data analysis obtained three nannofossil datums (boundaries): The First Occurrence (FO) of Sphenolithus pseudoradians NP19/NP20), the First Occurrence of Sphenolithus distentus (CP.16/CP.17), and the Last Occurrence (LO) Sphenolithus predistentus (NP.23/NP.24. The zonal boundary was determined based on calcareous nannoplankton; the Late Eocene to Middle Oligocene boundary of the Tonasa Formation was found in this section. Interestingly, throughout this period, the marker species in this section is Sphenolithus . In addition, the presence of Sphenolithus , Discoaster , and Zygrhablithus bijugatus indicated that the basin was in warm water condition.
... Reworked Cretaceous taxa (e.g., Arkhangelskiella cymbiformis, Broinsonia parca, Eiffellithus eximius, E. gorkae, E. turriseiffelii, Micula concava, Watznaueria barnesiae and Uniplanarius sissinghii), and Paleogene taxa such as Ericsonia cava, Chiasmolithus bidens, S. radians, S. primus, Pontosphaera exilis and R. umbilicus are common throughout the succession. The calcareous nannofossil zonation and taxonomy adopted in this work are based principally on Agnini et al. (2017). The inferred absolute ages are from Agnini et al. (2017) and Raffi et al. (2020). ...
... The calcareous nannofossil zonation and taxonomy adopted in this work are based principally on Agnini et al. (2017). The inferred absolute ages are from Agnini et al. (2017) and Raffi et al. (2020). Quantitative distribution patterns of the identified taxa reveal three main bioevents of early Miocene age. ...
... This event has been considered synchronous in low and mid-latitude oceanic regions (e.g., Bukry, 1973;Fornaciari et al., 1990;Olafsson, 1991). Backman et al. (2012) and Agnini et al. (2017) used this event as a zonal boundary for their CNM5 Zone and dated it at 19.01 Ma. In the Mediterranean region, there is some debate among earlier workers on the reliability of S. belemnos as a marker (e.g., Roth et al., 1971;Müller, 1978;Ellis and Lohman, 1979;Theodoridis, 1984). ...
The absence or rarity of some global marker taxa in the semi-restricted Suez rift basin has led to uncertainty with respect to the age of the early syn-rift deposits. To tackle this issue, high-resolution foraminiferal and calcareous nannofossil biostratigraphy was undertaken on sections in the Wadi Baba area at the eastern basin margin. Two planktic foraminiferal bioevents of early Miocene age are recognized: First Occurrences (FOs) of Globigerinoides subquadratus and Trilobatus sicanus. These bioevents define three zones/subzones: MMi2b, MMi2c-MMi3 and MMi4. Calcareous nannofossil analysis provided the basis for the definition of three zones: CNM4 to CNM6 based on FOs of Helicosphaera ampliaperta and Sphenolithus belemnos, and the first common occurrence of S. heteromorphus. Our results assign a new age estimate of late Aquitanian to early Burdigalian (<19.01 Ma) for the Nukhul Formation, and Burdigalian to early Langhian for the Rudeis Formation, with three possible hiatuses. Integration of benthic foraminiferal biofacies, lithofacies and nannofossil paleoecological markers reveals a broad range of paleoenvironments, from shoreface to upper bathyal. The Nukhul Formation was deposited in nearshore, nutrient-rich, well-oxygenated conditions. Deeper water environments of neritic to upper bathyal prevailed during the Rudeis Formation. Comparison with coeval deposits in the offshore area of the basin reveals significant paleoenvironmental variability during the Burdigalian associated with episodic subsidence along basinal faults. Climate-sensitive taxa and oxygen isotope data indicate a prevalence of warm paleoclimatic conditions. Our results suggest the development of a seaway connecting the Gulf of Suez with the Mediterranean during the early Miocene rather than Chattian.
... In addition to the information derived from geochemical proxies, fundamental insights on the paleoclimatic and paleoceanographic evolution during the late Eocene-early Oligocene come from the spatiotemporal distribution and abundances of calcareous nannofossils, mainly consisting of the fossil tests of coccolithophores (Agnini et al., 2017). In modern oceans, haptophyte algae are important primary producers of organic and inorganic carbon (Rost & Riebesell, 2004). ...
The Eocene‐Oligocene transition (EOT; ∼34 Ma) was one of the most prominent global cooling events of the Cenozoic, coincident with the emergence of continental‐scale ice‐sheets on Antarctica. Calcareous nannoplankton experienced significant assemblage turnover at a time of long‐term surface ocean cooling and trophic conditions, suggesting cause‐effect relationships between Antarctic glaciation, broader climate changes, and the response of phytoplankton communities. To better evaluate the timing and nature of these relationships, we generated calcareous nannofossil and geochemical data sets (δ¹⁸O, δ¹³C and %CaCO3) over a ∼5 Myr stratigraphic interval recovered across the EOT from IODP Site U1509 in the Tasman Sea, South Pacific Ocean. Based on trends observed in the calcareous nannofossil assemblages, there was an overall decline of warm‐oligotrophic communities, with a shift toward taxa better adapted to cooler more eutrophic conditions. Assemblage changes indicate four distinct phases caused by temperature decrease and variations in paleocurrents: late Eocene warm‐oligotrophic phase, precursor diversity‐decrease phase, early Oligocene cold‐eutrophic phase, and a steady‐state cosmopolitan phase. The most prominent shift in the assemblages occurred during the ∼550 kyr‐long precursor diversity‐decrease phase, which has relatively high bulk δ¹⁸O and %CaCO3 values, and predates the phase of maximum glacial expansion (Earliest Oligocene Glacial Maximum–EOGM).
... Although the Red Bank has been previously reported as Miocene-Pliocene (Flores, 1952) and upper Eocene to Miocene (Cornec, 2004;2015), the present study identified the chronostratigraphic position of the whole of the Red Bank group as upper Paleocene to lower Eocene. Calcareous nannofossils, which represent global biostratigraphic zones NP9 and NP10 (Martini, 1971;Okada and Bukry, 1980;Agnini et al., 2017), were recovered from several samples (Table 3). Key nannofossils recovered from the Red Bank included Prinsius bisuleus, Toweius eminens, Toweius tovae, and Heliolithus cantabriae. ...
The informal upper Paleocene to lower Eocene Red Bank group crops out in several areas of the Cayo and Orange Walk districts of northern Be-lize including the study area of the present report, which is the area around the oil fields of Spanish Lookout and Never Delay. Previous studies, which assigned the wrong age to the Red Bank group, described the Red Bank as mainly a clay (or soft claystone) deposit containing minor carbonate and evaporite beds and nodules. However, our present research, which relies on new petrographic and cartographic techniques, revealed that the Red Bank group is a complex stratigraphic unit of open estuarine origin that has a depositional history closely linked to global climatic and eustatic events. Well-log correlation in the study area around the Spanish Lookout and Never Delay oil fields suggests that the Red Bank unconformably overlies the Upper Cretaceous Barton Creek limestones. In fact, the clay deposits of the Red Bank fill caverns and karstic features within the upper part of the Bar-ton Creek limestones, and thick clay accumulations lie within karstic paleo-valleys such as the long, northeast-trending, fault-bounded karstic valley within the study area.
... This method was applied to 50 specimens of discoasterids and 50 specimens of helicoliths, while for the stratigraphically significant but very rare taxa (e.g., Ceratolithaceae family) a minimum of 100 FOV Table 1 Coring summary according to the initial reports of the DSDP, Leg 42A (Hsü et al., 1978 (with approximately the same density) were analysed, following the determination of the biostratigraphic events described by Backman et al. (2012). Zone assignment for the Site 378 record followed the biostratigraphic scheme of Agnini et al. (2017), Backman et al. (2012), and Di Stefano and Sturiale (2010), correlated to Martini (1971) standard biozones. The numerical age of the CN biozone boundaries is after Agnini et al. (2017). ...
... Zone assignment for the Site 378 record followed the biostratigraphic scheme of Agnini et al. (2017), Backman et al. (2012), and Di Stefano and Sturiale (2010), correlated to Martini (1971) standard biozones. The numerical age of the CN biozone boundaries is after Agnini et al. (2017). Additionally, nannofossil bioevents of Di Stefano and Sturiale (2010) identified in the Mediterranean region are used for the better constraint of the biostratigraphic assignment. ...
... The biostratigraphic analysis is based on the detection of certain CN biohorizons (Di Stefano and Sturiale, 2010;Agnini et al., 2017, Fig. 5). In particular, the occurrence of C. acutus recorded only in the basal part of core 11Z enables correlation with the CN biozone NN12 (Martini, 1971), which corresponds to biozone CNPL1 (Backman et al., 2012;Agnini et al., 2017). Accordingly, the Top (T) of C. acutus occurs at 309.4 mbsf in the core 11Z; this bioevent, absent in core 3A, is followed by the Fig. 3. Geochemical results in (a) Core 3A, (b) Core 11Z. ...
... 15 Ma (e.g. Agnini et al., 2017). Despite the significant error in the MO-2 fine tuff, the obtained 40 Ar/ 39 Ar age data are consistent with biostratigraphic ranking of volcaniclastic samples (Figure 12; Csibri et al., 2018;Holcová et al., 2019;Kováč et al., 2018;Rybár et al., 2015Rybár et al., , 2016Šarinová, Hudáčková, et al., 2021;Zlinská, 2016). ...
The Pannonian Basin System originated from the collision of the African and European tectonic plates, followed by the Miocene extensional collapse that led to the development of a back‐arc basins. Accurate dating is essential to comprehend the tectono‐volcanic evolution of the region, particularly in the under‐studied Danube Basin. Single‐grain ⁴⁰ Ar/ ³⁹ Ar dating has revealed that volcanic activity in the Danube Basin commenced around 14.1 million years ago, aligning with previous biostratigraphic and radioisotope data from nearby volcanic fields. The initial Middle Miocene pyroclastic deposits were generated by intermediate high K calc‐alkaline magmas, contributing significantly to the deposition of thick layers of fine vitric tuffs. The timing and chemistry of the volcanism are consistent with the Badenian rift phase in the Middle Miocene within the Carpathian–Pannonian region, suggesting an intraplate back‐arc volcanic environment. Three‐dimensional imaging has exposed the buried Kráľová stratovolcano, revealing its impressive scale with a thickness between 2620 and 5000 m and a base diameter of 18–30 km. Such dimensions place it among the ranks of the world's largest stratovolcanoes, indicating its substantial impact on the evolution of the Carpathian–Pannonian area. The complex formation history of the stratovolcano points to multiple phases of growth. Furthermore, the basin controlling Mojmírovce‐Rába fault's intersection with the stratovolcano implies that fault activity was subsequent to the volcanic activity, being younger than 14.1 million years. Regional age data consistently indicates that volcanic activity in the Danube Basin reached its zenith just prior to and during the lower/upper Badenian sea‐level fall (Langhian/Serravallian). K‐metasomatism is unique to the stratovolcanic structures and is not observed in the wider regional setting. This study supports the notion of an intricate, interconnected subterranean intrusive system within the stratovolcano, underscoring the complex interplay between geological structures and volcanic processes.
... Pelagic carbonate rocks as the Elat Formation usually contain many nannofossils (Agnini et al., 2017). These taxa are very small marine microfossils, oval, rod, star-shaped, nannofossil belongs to the protist kingdom, phylum hatophyta comporised of calcite plates generally produced by unicellular marine algal coccolithophore as a parent cell, limestone composisition, with a size of ±1-25 μm (Isnaniawardhani, 2017;Widhiyatmoko et al., 2023) Nannofossil analysis provides good accuracy in determining relative ages of marine sediment because of the abundance, rapid evolution and wide distribution (Isnaniawardhani, 2015;Raffi et al., 2022). ...
The Kei Besar Island is mainly composed of the Elat Formation carbonate rocks. This research was conducted to determine the nannofossils assemblages in the Elat Formation to interpret the depositional dynamics during its formation. Lithological observations and sampling for nannofossil analysis were carried out on three measured stratigraphic sections: Section 1 - Hollat, Section 2 - Ngurdu, and Section 3 - Mata Hollat. A total of 47 species assigned to 25 genera of nannofossils were identified in 45 selected samples. The succession of the Elat Formation in the study area formed at NP16 to N17 or Middle Eocene. Stratigraphic reconstruction supported by biostratigraphy analysis shows that Section 3 at the lower (NP16 to NP 17), Section 2 in the middle part (NP 17), and Section 1 at the upper (NP 17). R-mode cluster analysis of nannofossils defined four species clusters (assemblies A, B, C and D) that tend to occur together. Q-mode cluster analysis defined five depth-distribution clusters (1, 2, 3, 4, and 5), each deposited under similar conditions. Based on large foraminifera, the succession was formed in fore reef setting in neritic bathymetric zone. Coarsening and thickening upward supported by the nannofossil assemblages indicate depositional dynamics which tend to be shallower. Reworked fossils, commonly found at the lower of the Elat Formation, show the mechanism of turbid currents in early deposition.
... The zonation schemes for planktonic foraminifera and calcareous nannofossils used in this study are based on Lirer et al. (2019), Agnini et al. (2017), Backman et al. (2012), Fornaciari et al. (1996), and Raffi et al. (2003), as established for the Mediterranean region. These schemes are correlated with the standard-zonation nannofossil schemes of Martini (1971) and Okada and Bukry (1980). ...
Due to modern hydrocarbon development and exploration activities throughout the onshore Nile Delta of Egypt, a high-resolution biochronologic sequence stratigraphy of the Neogene sequence was conducted to illustrate the gas-bearing reservoirs' depositional sequences. Our study used a multidisciplinary approach comprising biostratigraphy, facies analysis, geophysical logs, and seismic data to shed light on the Neogene stratigraphic framework. The biostratigraphic analysis of planktonic foraminifera and calcareous nannofossils allowed the recognition of six zones and/or subzones and nine zones, respectively. An open-shelf environment was suggested for the Middle–Upper Miocene Sidi Salem Formation, while the Upper Miocene Qawasim and Abu Madi formations were deposited under stressed environmental conditions interpreted as estuary facies. The Lower Pliocene (Zanclean) succession deposited in the middle to outer shelf domains, including the upper-bathyal environments. Seven depositional sequences bounded by six major sequence boundaries were recognized from Serravallian to Zanclean times. These boundaries significantly influenced changes in reservoir properties and architecture of the incised valley fills. The sea-level oscillations are interpreted by correlating the sequence boundaries and flooding surfaces with global eustatic charts.
... Calcareous nannofossils are especially good markers for their quick evolution, since Late Triassic and broad geographic distribution, as well as small size and common occurrence already in small rock pieces. Biostratigraphical data were intensively collected, refined and improved for several decades [25][26][27]. Today, the key synthesis is available in the Nannotax database [28]. Nannofossils can be easily analysed in art primings, being the main component of chalk (up to 98%) and due to their minute size < 30 μm. ...
Chalk has been used since Antiquity for various purposes, and since Gothic for preparatory layers of painted cultural heritage objects. Several materials are called chalk in Cultural Heritage, but this work especially focuses on chalk composed of calcareous nannofossils (up to 98%). These are fossil remains of photoautotrophic algae generally smaller than 30 μm. They are mainly visible as platelets of various shapes under a cross-polarised or scanning electron microscope. The provenance of chalk can be determined using calcareous nannofossils due to their well-known paleobiogeographic localities. They are already used as proxies since the 90s in Cultural Heritage, but rarely for paintings. In this work, 6 chalk historical mining areas were chosen: Germany (Ruegen), France (Champagne, Meudon), Belgium (Mons), England (Norfolk) and Italy (Bologna). Natural and processed chalk were used as reference materials and compared to 3 original paintings. The difference between the chalks calcareous nannofossil assemblages was shown using multivariate statistical analysis based on species relative abundance. Marker nannofossil species were defined for each chalk locality. One painting material could not be originated due to the preservation of its nannofossils assemblage, but the origins of the rock chalk material from the two other paintings could be geographically located in France.
... Ma) and CNM4 (20.49 Ma), respectively (Agnini et al., 2017). Lithostratigraphic succession identified Urucutuca Formation (3722-1507 m) and Rio Doce Formation (1507-578 m). ...
Over the last 66 million years, Earth has undergone dramatic climate changes, shifting from a warm greenhouse to the more recent cold icehouse with polar ice caps in both hemispheres. Geological records show that the transition between these equilibrium states caused significant long-term eustatic sea-level and atmospheric CO2 decline paced by external orbital motions. Such eustatic variability influenced the stacking pattern of sedimentary successions, generating cyclic sequence boundaries that may be globally correlated. However, the impact of such oscillation along the Brazilian margin is largely unknown. This study used the natural gamma-ray log from a well (ES-2) at the offshore Espı ́rito Santos Basin (western South Atlantic) measured between late-Palaeocene and late-Miocene. Null hypothesis tests - evolutionary Average Spectral Misfit and Correlation Coefficient of no orbital modulation - were executed to confirm the influence of astronomical parameters. The evolutionary Time Optimization algorithm was used to extract the sedimentation rate and depositional time. The anchored timescale shows a chronological interval placed between 58.97 and 7.72 � 0.1 Ma (mid-Thanetian – late Tortonian), mostly influenced by long-eccentricity and short-eccentricity (405 kyr and ca 100 kyr, respectively) and obliquity (ca 40 kyr) and their respective amplitude modulations (ca 2.4 Myr and 1.2 Myr). Applying the Integrated Prediction Error Filter Analysis and a highresolution age model, this study identified main depositional trends through time and correlated them to global sea-level change. The correlation indicates that several intervals of global sea-level reduction agree with a regressive trend at the ES-2 site, but this relation is affected during enhanced regional tectonic activity intervals, as related to the emplacement of the Abrolhos Archipelago. The strategy adopted here is a way to join cyclostratigraphy and sequence stratigraphy, and promotes high-resolution local-toglobal correlation by identifying key stratigraphic surfaces. This will be relevant for palaeoclimatic studies and the geoscientific industry.
