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The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid-paleolatitudes are reasonably well constrained for OAE2, similar data from high paleolatitudes are lacking. Here, we present palynostratigraphy and organic-carbon isotope stratigraphy from the Sverdrup Basin, Axel Heiberg Island (Canada). It is shown that episodes of high marine organic-carbon burial at paleolatitudes of ~70°N is contemporaneous with the widely observed occurrence of black shale deposition during OAE2. Paleontological, lithological, and geochemical data indicate normal marine conditions with persistent anoxic bottom waters during OAE2. The results imply that the high marine primary productivity pulse during OAE2 may have caused massive organic-carbon burial on the Arctic shelf in general, with important implications for hydrocarbon source-rock distribution in the Arctic region. [ABSTRACT FROM AUTHOR]

The article presents a case study of spectral gamma-ray characterisation of the deltaic Cretaceous Atane Formation in Nuussuaq Basin, Greenland. It states that gamma-ray logs are used for lithology indicator and petrophysical model which are emitted by three elements such as potassium, thorium, and uranium. The case study reportedly fails to resolve the grain-size variation of the formation because of the presence of the elements.

The generally warm Cretaceous (c. 145-66 Ma) climate culminated in the mid Cretaceous Hot Greenhouse climate (95-85 Ma). Another characteristic feature of the Cretaceous period is a high number of Oceanic Anoxic Events (OAE) related with major carbon cycle perturbations. While the Lower Cretaceous successions from equatorial region and middle latitudes are relatively well studied, sections from High Arctic settings are sparse and occasionally suffering from poor age constrains.The present study was performed within the LoCrA (Lower Cretaceous Basin Studies in The Arctic) consortium and focused on the Lower Cretaceous succession on Spitsbergen (this study) and the Barents Sea. The Lower Cretaceous succession on central Spitsbergen is divided into: the Rurikfjellet, Helvetiafjellet and Carolinefjellet formations. Each formation was deposited under different environmental conditions, ranging from open to shallow marine (Rurikfjellet and Carolinefjellet formations) to fluvio-deltaic (Helvetiafjellet Formation). Our improved age model (based on palynology, macrofossils and organic stable carbon isotopes) for the Rurikfjellet and Helvetiafjellet formation confirms that these two units span the Valanginian to lower Aptian. Dinoflagellate cysts (dinocysts) are excellent for biostratigraphy as well as paleoecology. Dinoflagellates, forming the primary component of marine plankton, are sensitive to various environmental factors: temperature, salinity, nutrient availability, etc. Within the studied interval a number of dinocyst events occurs, which appears to be synchronous between Spitsbergen and other high-Arctic basins (e.g. in Greenland and Arctic Canada). However, some of the characteristic Early Cretaceous dinocyst taxa, are either absent or only observed locally. Here, we investigate if the changes in the dinocyst assemblages are an effect of the local environmental changes or an effect of the regional to global climate perturbations. [ABSTRACT FROM AUTHOR]