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The Paleocene–Eocene transition was a time of short-term rapid climatic and biotic change, superimposed on a long-term warming trend. The response of shallow tropical carbonate systems to past rapid warming is important to understand in the context of ongoing and future anthropogenic global warming. Larger benthic foraminifera (LBF) were abundant and important components of shallow water ecosystems throughout the early Paleogene and are sensitive to environmental change, making them ideal organisms to track shallow marine biodiversity. Furthermore, through the use of integrated bio- and chemostratigraphy it is possible to correlate the shallow (<100 m) and deep water realms to create a regional stratigraphic framework for the time period. Here we present a new LBF biostratigraphic and high-resolution carbonate carbon isotopic record spanning the Paleocene–Eocene transition from the onshore sub-surface of the United Arab Emirates (UAE). Results show a turnover event in the LBF assemblage during the early Eocene, wherein there are a number of first and last occurrences of species. However, assemblages remain generally stable coincident with the large negative carbon isotope excursion interpreted to be the onset of the Paleocene–Eocene thermal maximum (PETM). Turnover in the LBF assemblage in the early Eocene likely occurred due to the crossing of a long-term climatic and oceanographic threshold. The impacts of this long-term climatic change on the overall biotic assemblage at this site are significant, with LBF outcompeting a previously diverse community of corals, gastropods, and bivalves to become the dominant carbonate producers through the Paleocene–Eocene­ transition. Despite this, modern studies suggest that LBF are not immune to impacts of anthropogenic climate change, perhaps due to the significantly higher rates of change in the modern compared to the Paleocene–Eocene transition.

The Paleocene–Eocene Thermal Maximum (PETM) was a global hyperthermal event ∼56 Ma characterized by massive input of carbon into the ocean–atmosphere system and global warming. A leading hypothesis for its trigger is the emplacement of the North Atlantic Igneous Province (NAIP), with extensive extrusion/intrusion of igneous material into nearby sedimentary basins, forcing local uplift and warming‐inducing carbon emissions. It remains unclear if oceanographic changes in the North Sea–Norwegian Sea–Arctic basins, such as anoxia and productivity, were causally linked to local NAIP uplift/activity, and at what time scales these perturbations occurred. To test mechanisms and time scales, we present geochemical proxies (XRF analysis, clay mineralogy, molybdenum isotopes, and pyrite framboid size distribution) in undisrupted marine sediment core E−8X located in the central North Sea. We find evidence for a rapid onset of anoxia/euxinia at the negative carbon isotope excursion from redox proxies, followed by a gradual drawdown of molybdenum/total organic carbon (Mo/TOC) during the PETM main phase indicative of tectonically‐restricted basin likely from NAIP uplift. A short‐lived increase in Mo, pyrite and TOC occurred during a precursor event associated with a sedimentary mercury pulse indicative of volcanic activity. We suggest thermal uplift and flood basalt volcanism tectonically restricted the North Sea and tipped it into an euxinic state via volcanic emission–oceanographic feedbacks inducing eutrophication. This fine temporal separation of tectonic versus climatic geochemical proxies, combined with pulsed NAIP volcanism, demonstrates that Large Igneous Province emplacements can, at least locally, result in ocean biogeochemical feedbacks operating on relatively short timescales. Paleoceanographic reconstructions of the North Sea during the Paleocene‐Eocene Thermal Maximum via high resolution geochemical dataWe find that redox, productivity and basin restriction changes occurred before and after the carbon isotope excursionWe argue that precursor and initial paleoceanographic changes were driven by Large Igneous Province emplacement and regional uplift Paleoceanographic reconstructions of the North Sea during the Paleocene‐Eocene Thermal Maximum via high resolution geochemical data We find that redox, productivity and basin restriction changes occurred before and after the carbon isotope excursion We argue that precursor and initial paleoceanographic changes were driven by Large Igneous Province emplacement and regional uplift

Multimillion-year proxy records across the Paleocene and Eocene show prominent variations on orbital time scales. The cycles, which have been identified at various sites across the globe, preferentially concentrate spectral power at eccentricity and precessional frequencies. It is evident that these cycles are an expression of changes in global climate and carbon cycling paced by astronomical forcing. However, little is currently known about the link between orbital forcing and the carbon cycle-climate system and the amplitude of associated atmospheric CO2variations. Here we use simple and complex carbon cycle models to explore the basic effect of different orbital forcing schemes and noise on the carbon cycle. Our primary modeling target is the high-resolution, ~7.7 Myr long, benthic isotope record at Ocean Drilling Program Site 1262 in the South Atlantic. For direct insolation forcing (as opposed to artificial eccentricity-tilt-precession), one major challenge is understanding how the system transfers spectral power from high to low frequencies. We discuss feasible solutions, including insolation transformations analogous to electronic AC-DC conversion (DC'ing). Regarding mechanisms, we focus on tropical insolation and a long-term carbon imbalance in terrestrial organic burial/oxidation but do not rule out other scenarios. Our analysis shows that high-latitude mechanisms are unlikely drivers of orbitally paced changes in the late Paleocene-early Eocene (LPEE) Earth system. Furthermore, we provide constraints on the origin and isotopic composition of a possible LPEE cyclic carbon imbalance/source responding to astronomical forcing. Our simulations also reveal a mechanism for the large d13C-eccentricity lag at the 400 kyr period observed in Paleocene, Oligocene, and Miocene sections. We present the first estimates of orbital-scale variations in atmospheric CO2during the late Paleocene and early Eocene. We present the first estimates of orbital-scale variations in atmospheric CO2during the late Paleocene and early EoceneHigh-latitude mechanisms are unlikely drivers of orbitally paced changes in the late Paleocene-early EoceneWe also reveal a mechanism for the large d13C-eccentricity lag at the 400 kyr period observed in Paleocene, Oligocene, and Miocene sections

The Upper Cretaceous to Paleocene succession cropping out at the Bottaccione section (Gubbio, central Italy) represents a classical Tethyan setting that served as a standard for the construction of the geomagnetic polarity time scale. Available biomagnetostratigraphy suggests that the Danian interval of the Bottaccione section is condensed relative to other outcrops in the area and/or might contain a non-identified stra tigraphic gap. By contrast, a new high-resolution integrated stratigraphic record presented here, including bio-, magneto-, chemo-, and cyclostratigraphy, provides evidence that the Bottaccione record is complete and comparable to other successions outcropping in the Umbria-Marche. However, the paleomagnetic signal of this classical section is partially corrupted in the upper Danian. Recognition of orbitally-forced sedimentary cycles, corresponding to the long eccentricity (405 kyr), and litho- and biostratigraphic correlation with the nearby Contessa Highway which provides a robust magnetostratigraphic record, allows a cyclochronological comparison with ODP Sites 1209 and 1262 and the Zumaia land-based succession. Cycle counting suggests the presence of 10 long-eccentricity cycles between the Cretaceous/Paleogene (K/Pg) boundary and the top C27n event, which has implications for the age of the latter chronohorizon.