Data report: calcium carbonate and total organic carbon records from IODP Expedition 339 Sites U1395 and U1391

Abstract

Sedimentary inorganic calcium carbonate CaCO3 and total organic carbon (TOC) are two of the most commonly used indicators of past oceanic productivity. In this report, we present CaCO3 and TOC records from Integrated Ocean Drilling Program Expedition 339 Sites U1385 and U1391 drilled in the southwest Iberian margin. Identified as a key region to establish the marine-ice-terrestrial linkages crucial for understanding the Earth’s climate system, this margin is also characterized by seasonal coastal upwelling–related high primary production. These IODP sites constitute a depth transect across a productivity gradient allowing for the investigation of the impact of climate variations on marine production and preservation. A total of 420 samples were analyzed for the 75–100 meters composite depth (mcd) interval at Site U1385 and for the 160–220 mcd interval at Site U1391. Results show at least two scales of variability for both CaCO3 and TOC, which are comparable between sites but have a better-defined long-term trend on the CaCO3 record.