Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: The sedimentary C/N and δ13C in six Yangtze floodplain (China) lake sediment cores since 1800s CE. The sediment cores were dated using lead-210. C/N ratios and δ13C were analysed at the National Environmental Isotope Facility at the British Geological Survey, after preliminary treatment (HCl (5%) to remove calcites) in the School of Geography at the University of Nottingham, using Costech Elemental Analyser (EA) and on-line VG TripleTrap and Optima dual-inlet mass spectrometer. TOC and TN content were calibrated using the acetanilide standard. δ13C was calibrated to the Vienna Pee Dee Belemnite (VPDB) using laboratory standards which were calibrated against NBS-18, NBS-19 and NBS-22.

Description: The Bering Sea is one of the most biologically productive regions in the marine system and plays a key role in regulating the flow of waters to the Arctic Ocean and into the subarctic North Pacific Ocean. Cores from Integrated Ocean Drilling Program (IODP) Expedition 323 to the Bering Sea provide the first opportunity to obtain reconstructions from the region that extend back to the Pliocene. Previous research at Bowers Ridge, south Bering Sea, has revealed stable levels of siliceous productivity over the onset of major Northern Hemisphere Glaciation (NHG) (circa 2.85-2.73 Ma). However, diatom silica isotope records of oxygen (d18Odiatom) and silicon (d30Sidiatom) presented here demonstrate that this interval was associated with a progressive increase in the supply of silicic acid to the region, superimposed on shift to a more dynamic environment characterized by colder temperatures and increased sea ice. This concluded at 2.58 Ma with a sharp increase in diatom productivity, further increases in photic zone nutrient availability and a permanent shift to colder sea surface conditions. These transitions are suggested to reflect a gradually more intense nutrient leakage from the subarctic northwest Pacific Ocean, with increases in productivity further aided by increased sea ice- and wind-driven mixing in the Bering Sea. In suggesting a linkage in biogeochemical cycling between the south Bering Sea and subarctic Northwest Pacific Ocean, mainly via the Kamchatka Strait, this work highlights the need to consider the interconnectivity of these two systems when future reconstructions are carried out in the region.