Authigenic formation of clay minerals in the abyssal North Pacific

This study was funded by a Blavatnik postdoctoral fellowship to ZS, an Isaac Newton Trust grant to AVT and ZS, ERC StG 307582 (CARBONSINK) to AVT, and DFG grant number 458035111 to ZS. The cruise on-board RV Kilo Moana was funded by NSF Ocean Acidification grant number OCE1220600.Present estimates of the biogeochemical cycles of calcium, strontium and potassium in the ocean reveal large imbalances between known input and output fluxes. Using pore fluid, incubation and solid sediment data from North Pacific multi-corer cores we show that, contrary to the common paradigm, the top centimetres of abyssal sediments can be an active site of authigenic precipitation of clay minerals. In this region, clay authigenesis is the dominant sink for potassium and strontium and consumes nearly all calcium released from benthic dissolution of calcium carbonates. These observations support the idea that clay authigenesis occurring over broad regions of the world ocean may be a major buffer for ocean chemistry on the time scale of the ocean overturning circulation, and key to the long-term stability of Earth's climate.Publisher PDFPeer reviewe