Claudia Agnini

Claudia Agnini
University of Padova | UNIPD · Department of Geosciences

PhD

About

130
Publications
50,966
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2,988
Citations
Citations since 2016
62 Research Items
2181 Citations
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600

Publications

Publications (130)
Article
Full-text available
The absolute position during the Cenozoic of northern Zealandia, a continent that lies more than 90% submerged in the southwest Pacific Ocean, is inferred from global plate motion models, because local paleomagnetic constraints are virtually absent. We present new paleolatitude constraints using paleomagnetic data from International Ocean Discovery...
Preprint
Cyclostratigraphy and astrochronology are now at the forefront of geologic timekeeping. While this technique heavily relies on the accuracy of astronomical calculations, solar system chaos limits how far back astronomical calculations can be performed with confidence. High-resolution paleoclimate records with Milankovitch imprints now allow reversi...
Article
The middle Eocene climatic optimum (ca. 40 Ma) stands out as a transient global warming phase of ∼400 k.y. duration that interrupted long-term Eocene cooling; it has been associated with a rise in atmospheric CO2 concentrations that has been linked to a flare-up in Arabia-Eurasia continental arc volcanism. Increased organic carbon burial in the Tet...
Article
Full-text available
Sediment mass accumulation rate (MAR) is a proxy for paleoceanographic conditions, especially if biological productivity generated most of the sediment. We determine MAR records from pelagic calcareous sediments in Tasman Sea based on analysis of 11 boreholes and >3 million seismic reflection horizon picks. Seismic data from regions of 10,000–30,00...
Article
Full-text available
Environmental and biotic responses to early Eocene hyperthermal events in the southwest Pacific are critical for global paleoclimate reconstructions during Cenozoic greenhouse intervals, but detailed multidisciplinary studies are generally missing from this time and location. Eocene carbonate sediments were recovered during International Ocean Disc...
Article
Full-text available
The base of the Priabonian Stage is one of two stage boundaries in the Paleogene that remains to be formalized. The Alano section (NE Italy) was elected by consensus as a suitable candidate for the base of the Priabonian during the Priabonian Working Group meeting held in Alano di Piave in June 2012. Further detailed research on the section is now...
Article
The modern Eastern Equatorial Pacific (EEP) Ocean is a high nutrient low chlorophyll (HNLC) upwelling region and a large oceanic source of carbon to the atmosphere. During the last deglaciation, the EEP played a major role in the outgassing of carbon dioxide into the atmosphere from the upwelling surface water system of CO2-enriched deep-water mass...
Article
It has been argued that the beginning of significant pelagic calcification could have been linked to the Carnian Pluvial Episode (CPE), a climate change in the Late Triassic (~234–232 Ma) that was marked by C-cycle disruption and global warming. Nevertheless, abundant calcareous nannofossils have been described so far only in post-CPE rocks, and th...
Article
In New Caledonia, upper Cretaceous to Palaeogene sedimentary rocks record a regional tectonic shift from Cretaceous extension to Eocene compression, which led to the obduction of oceanic mantle onto the northeastern tip of the submerged Zealandia continent. This study provides new descriptions of these successions in the region of the Gouaro anticl...
Article
Full-text available
A diverse assemblage of bodily preserved sponges has been recovered from a lower Lutetian tuffite horizon in the Chiampo Valley, Lessini Mountains, Italy. The sponge assemblage is dominated by hexactinellids and lithistids. Using uniformitarian criteria, the composition of the assemblage suggests a water depth greater than 200 m. Sponges are often...
Article
Full-text available
Much of our understanding of Earth's past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a...
Article
Full-text available
This work aims at providing an updated scenario on the underrepresentation of women in the Italian university system in the area of geosciences in the last two decades. The retrieved official data on permanent full and associate professors in the 19-years considered highlight some positive trends: an increase in the number of female full professors...
Article
The latest Triassic was an interval of prolonged biotic extinction culminating in the end-Triassic Extinction (ETE). The ETE is now associated with a perturbation of the global carbon cycle just before the end of the Triassic that has been attributed to the extensive volcanism of the Circum-Atlantic Magmatic Province (CAMP). However, we attribute t...
Article
Full-text available
Data from International Ocean Discovery Program (IODP) Expedition 371 reveal vertical movements of 1–3 km in northern Zealandia during early Cenozoic subduction initiation in the western Pacific Ocean. Lord Howe Rise rose from deep (~1 km) water to sea level and subsided back, with peak uplift at 50 Ma in the north and between 41 and 32 Ma in the s...
Article
Full-text available
The early to middle Eocene is marked by prominent changes in calcareous nannofossil assemblages coinciding both with long‐term climate changes and modification of the North Atlantic deep ocean circulation. In order to assess the impact of Eocene climate change on surface water environmental conditions of the Northwest Atlantic, we developed calcare...
Article
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The Middle Eocene Climatic Optimum (MECO) was an unusual global warming event that interrupted the long‐term Eocene cooling trend ca. 40 Ma. Here we present new high‐resolution bulk and benthic isotope records from South Atlantic ODP Site 702 to characterize the MECO at a high latitude setting. The MECO event, including early and peak warming as we...
Conference Paper
Full-text available
The latest Triassic was an interval of prolonged biotic extinction culminated by the end-Triassic Extinction, which is associated with a pronounced perturbation of the global carbon cycle that can be connected to extensive volcanism of the Central Atlantic Magmatic Province (CAMP). Earlier chaotic perturbations of the global carbon cycle can also b...
Article
A combined light microscope-scanning electron microscope study of exceptionally well-preserved calcareous nannofossil assemblages from clay-rich middle Eocene sediments recovered at IODP Site U1410 (NW Atlantic Ocean) has enabled us to document a new evolutionary lineage within Coccolithus-like placoliths that have well-developed near-axial or diag...
Article
Full-text available
At least five major paleo-canyons have been identified in sediment sequences along the western flank of the Tampico-Misantla Basin in eastern Mexico. These were formed during the late Paleocene (~56 Ma) and cut into thick unconsolidated Paleocene bathyal sediments. Sediments within two of these canyons have been studied in more detail. The Acatepec...
Conference Paper
Full-text available
The sponge fauna from a lower Lutetian tuffite horizon in the Chiampo Valley, Lessini Mountains, north-eastern Italy, consists of 32 species: 15 hexactinellid and 17 demosponges (15 lithistids and 2 hypercalcified). Such fauna shows affinities with sponges from the Eocene of Spain and the Cretaceous of Germany. The stratigraphical range of taxa as...
Article
The climatic changes during the Early-Middle Pleistocene transition are a key to understand the ecosystem dynamics that involved the Homo erectus-ergaster distribution. The Aalat pedostratigraphic succession represents a continental archive in the African Rift Valley (Eritrea), where remains of Homo around 1 Ma were identified. High-resolution magn...
Article
Full-text available
Palaeoclimate reconstructions of periods with warm climates and high atmospheric CO2 concentrations are crucial for developing better projections of future climate change. Deep-ocean1,2 and high-latitude3 palaeotemperature proxies demonstrate that the Eocene epoch (56 to 34 million years ago) encompasses the warmest interval of the past 66 million...
Article
Full-text available
We conducted an integrated magneto-biostratigraphic study of a 37 m-thick composite section exposed at two sites near Nouméa (New Caledonia). The section contains a transition from pelagic micrite to terrigenous-rich calciturbidites. This transition, observed regionally in coeval records of New Caledonia, marks a shift from pelagic sedimentation on...
Article
Full-text available
International Ocean Discovery Program (IODP) Expedition 371 drilled six sites in the Tasman Sea of the southwest Pacific between 27 July and 26 September 2017. The primary goal was to understand Tonga-Kermadec subduction initiation through recovery of Paleogene sediment records. Secondary goals involved understanding regional oceanography and clima...
Article
Full-text available
International Ocean Discovery Program (IODP) Expedition 371 drilled six sites in the Tasman Sea of the southwest Pacific between 27 July and 26 September 2017. The primary goal was to understand Tonga-Kermadec subduction initiation through recovery of Paleogene sediment records. Secondary goals involved understanding regional oceanography and clima...
Article
Full-text available
This study revises the mammal-bearing stratigraphic succession of Cava Gentile, near Cessaniti (Calabria, southern Italy), with the aim of dating the Late Miocene fossiliferous succession by the integration of mammal biochronology with sedimentology, magnetostratigraphy and marine biostratigraphy. Since the first discovery of mammal remains at Cess...
Conference Paper
Stable isotope studies from paleosoils developed in fluvio-lacustrine-palustrine environements can provide a proxy for paleoenvironmental change. This tool has the potential to elucidate if climate has any influence in the sedimentary facies. We analysed three types of carbonate concretions from paleosoils developed along the 285-m thick Aalat sect...
Article
Full-text available
Fine-grained magnetic particles in deep-sea sediments often statistically align with the ambient magnetic field during (and shortly after) deposition and can therefore record geomagnetic reversals. Correlation of these reversals to a geomagnetic polarity time scale is an important geochronological tool that facilitates precise stratigraphic correla...
Article
Full-text available
To fully understand the global climate dynamics of the warm early Eocene with its reoccurring hyperthermal events, an accurate high-fidelity age model is required. The Ypresian stage (56–47.8 Ma) covers a key interval within the Eocene as it ranges from the warmest marine temperatures in the early Eocene to the long-term cooling trends in the middl...
Chapter
Full-text available
Integrated Ocean Drilling Program (IODP) Expedition 342 recovered exceptional Paleogene to early Neogene sedimentary archives from clay-rich sediments in the northwest Atlantic Ocean. These archives present an opportunity to study Cenozoic climate in a highly sensitive region at often unprecedented resolution. Such studies require continuous record...
Poster
Full-text available
The Euganean Hills are a morphological expression of the tectonic processes that occurred in the Southern Alps during the late alpine time. In the southernmost hills, near Arquà Petrarca (Padova), discontinuous gouge layers occur along south-vergent slip planes within Scaglia Rossa and Maiolica Fms. The incohesive layers and bodies (flour-like mate...
Article
Full-text available
A global carbon-isotope curve for the Late Triassic has the potential for global correlations and new insights on the complex and extreme environmental changes that took place in this time interval. We reconstruct the global δ¹³Corg profile for the late Norian, improving on sparse published data from North American successions that depict a "chaoti...
Article
Full-text available
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...
Article
We present a minero-petrographic, geochemical and geochronological study of siderite orebodies from different localities of the Southern Alps (northern Italy). Siderite occurs as veins cutting the Variscan basement and the overlying Lower Permian volcano-sedimentary cover (Collio Fm.), and as both veins and conformable stratabound orebodies in the...
Article
Full-text available
To fully understand the global climate dynamics of the warm early Eocene with its reoccurring hyperthermal events, an accurate high-fidelity age model is required. The Ypresian Stage (56–47.8 Ma) covers a key interval within the Eocene as it ranges from the warmest marine temperatures in the early Eocene to the long-term cooling trends in the middl...
Article
Full-text available
The need for an update of the calcareous nannofossil biozonations proposed by Martini (1971) and Bukry (1973,1975), more than 40 years ago, prompted us to develop two new biozonations published in 2012 and 2014, one for the Miocene through Pleistocene interval and one for the Paleogene interval (Backman et al., 2012; Agnini et al., 2014). These bio...
Article
Full-text available
A marked switch in the abundance of the planktic foraminiferal genera Morozovella and Acarinina occurred at low-latitude sites near the start of the Early Eocene Climatic Optimum (EECO), a multi-million-year interval when Earth surface temperatures reached their Cenozoic maximum. Stable carbon and oxygen isotope data of bulk sediment are presented...
Article
Full-text available
We present records of stable carbon and oxygen isotopes, CaCO3 content, and changes in calcareous nannofossil assemblages across an 81 m thick section of upper Paleocene–lower Eocene marine sedimentary rocks now exposed along the Cicogna Stream in northeast Italy. The studied stratigraphic section represents sediment accumulation in a bathyal hemip...
Article
Full-text available
To assess the role played in the carbonate budget by calcifying phytoplanktonic organisms, it is necessary to provide reliable quantitative estimates of the calcite secreted by calcareous nannoplankton, which certainly have had a vital role in the global carbon cycle since the Jurassic by supplying organic carbon and calcium carbonate to the deep o...