-Carbon stable-isotope variation through the Cenomanian-Santonian stages is characterized using data for 1769 bulk pelagic carbonate samples collected from seven Chalk successions in England. The sections show consistent stratigraphic trends and δ 13 C values that provide a basis for highresolution correlation. Positive and negative δ 13 C excursions and inflection points on the isotope profiles are used to define 72 isotope events. Key markers are provided by positive δ 13 C excursions of up to + 2 ‰: the Albian/Cenomanian Boundary Event; Mid-Cenomanian Event I; the Cenomanian/Turonian Boundary Event; the Bridgewick, Hitch Wood and Navigation events of Late Turonian age; and the Santonian/Campanian Boundary Event. Isotope events are isochronous within a framework provided by macrofossil datum levels and bentonite horizons. An age-calibrated composite δ 13 C reference curve and an isotope event stratigraphy are constructed using data from the English Chalk. The isotope stratigraphy is applied to successions in Germany, France, Spain and Italy. Correlation with pelagic sections at Gubbio, central Italy, demonstrates general agreement between biostratigraphic and chemostratigraphic criteria in the Cenomanian-Turonian stages, confirming established relationships between Tethyan planktonic foraminiferal and Boreal macrofossil biozonations. Correlation of the Coniacian-Santonian stages is less clear cut: magnetostratigraphic evidence for placing the base of Chron 33r near the base of the Upper Santonian is in good agreement with the carbon-isotope correlation, but generates significant anomalies regarding the placement of the Santonian and Campanian stage boundaries with respect to Tethyan planktonic foraminiferal and nannofossil zones. Isotope stratigraphy offers a more reliable criterion for detailed correlation of Cenomanian-Santonian strata than biostratigraphy. With the addition of Campanian δ 13 C data from one of the English sections, a composite Cenomanian-Campanian age-calibrated reference curve is presented that can be utilized in future chemostratigraphic studies.The Cenomanian-Campanian carbon-isotope curve is remarkably similar in shape to supposedly eustatic sea-level curves: increasing δ 13 C values accompanying sea-level rise associated with transgression, and falling δ 13 C values characterizing sea-level fall and regression. The correlation between carbon isotopes and sea-level is explained by variations in epicontinental sea area affecting organic-matter burial fluxes: increasing shallow sea-floor area and increased accommodation space accompanying sea-level rise allowed more efficient burial of marine organic matter, with the preferential removal of 12 C from the marine carbon reservoir. During sea-level fall, reduced seafloor area, marine erosion of previously deposited sediments, and exposure of basin margins led to reduced organiccarbon burial fluxes and oxidation of previously deposited organic matter, causing falling δ 13 C values. Additionally, drowning of carbonate platforms during...

[1] Oceanic Anoxic Event 2 (OAE2), spanning the Cenomanian-Turonian boundary (CTB), represents one of the largest perturbations in the global carbon cycle in the last 100 Myr. The d 13 C carb , d 13 C org , and d 18 O chemostratigraphy of a black shale-bearing CTB succession in the Vocontian Basin of France is described and correlated at high resolution to the European CTB reference section at Eastbourne, England, and to successions in Germany, the equatorial and midlatitude proto-North Atlantic, and the U.S. Western Interior Seaway (WIS). D C (offset between d13 C carb and d 13 C org ) is shown to be a good pCO 2 proxy that is consistent with pCO 2 records obtained using biomarker d 13 C data from Atlantic black shales and leaf stomata data from WIS sections. Boreal chalk d18 O records show sea surface temperature (SST) changes that closely follow the D 13 C pCO 2 proxy and confirm TEX 86 results from deep ocean sites. Rising pCO 2 and SST during the Late Cenomanian is attributed to volcanic degassing; pCO 2 and SST maxima occurred at the onset of black shale deposition, followed by falling pCO 2 and cooling due to carbon sequestration by marine organic productivity and preservation, and increased silicate weathering. A marked pCO 2 minimum (∼25% fall) occurred with a SST minimum (Plenus Cold Event) showing >4°C of cooling in ∼40 kyr. Renewed increases in pCO 2 , SST, and d 13 C during latest Cenomanian black shale deposition suggest that a continuing volcanogenic CO 2 flux overrode further drawdown effects. Maximum pCO 2 and SST followed the end of OAE2, associated with a falling nutrient supply during the Early Turonian eustatic highstand.Citation: Jarvis, I., J. S. Lignum, D. R. Gröcke, H. C. Jenkyns, and M. A. Pearce (2011), Black shale deposition, atmospheric CO 2 drawdown, and cooling during the Cenomanian-Turonian Oceanic Anoxic Event, Paleoceanography, 26, PA3201,

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