Daniel Conley

Urea is the world’s most widely used nitrogen fertilizer. Elevated urea use can induce detrimental eutrophication of shallow surface waters in agricultural regions, accelerating water quality deterioration globally in these regions. This is a preview of subscription content, access via your institution Access options Subscribe to this journal We are sorry, but there is no personal subscription option available for your country.

Abstract Chemical weathering of silicate rocks redistributes major, minor and trace elements through coupled dissolution–precipitation reactions. These weathering processes drive shifts in ocean acid–base chemistry, modulating atmospheric carbon dioxide levels and providing a stabilizing feedback in the carbon cycle.

Genus Sceptroneis Ehrenberg Genus description and synapomorphies: elongated slightly curved heteropolar valves with indistinct central sternum; uniseriate striae with large areolae are occluded by rotae; apical pore fields present on both poles with single rimoportula Minimum clade age: Uppermost Santonian–Lowermost Campanian (~84–82 Mya); figs. 4A–C in Shimada et al. (2022) Sediment dating method: biostratigraphy based on ammonoids and inoceramids.