Bosin, Aleksandr A (2024): Analysis results of sediment core LV63-41-2, NW Pacific [dataset bundled publication]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.969083 (DOI registration in progress)
Always quote citation above when using data! You can download the citation in several formats below.
Abstract:
Sediment core LV63-41-2 (52°34' N, 160°01' E; water depth: 1924 m) was recovered from the NW Pacific off the Kamchatka Peninsula during the Russian–Chinese joint expedition on R/V Akademik M.A. Lavrentyev in 2013. The length of the core is 467 cm.
Chlorin
Chlorin content is assumed to reflect changes in primary surface ocean productivity because continental-derived chlorophyll contributes insignificantly to its composition in deep marine sediment (Harris et al., 1996). The chlorin content in core LV63-41-2 was measured by a Shimadzu UV-1650PC spectrophotometer at 1 cm resolution, using the same analytical reagents and pretreatment procedures proposed by Harris et al. (1996).
Total organic and inorganic carbon contents
Total organic carbon (TOC) and inorganic carbon contents (CaCO3) in core LV63-41-2 were measured at every 2 cm throughout the core by coulometry using an AN-7529 analyzer in the same way, which has been reported by Gorbarenko et al. (1998). TOC content was determined by calculating the difference between total carbon and inorganic carbon content.
Color b∗
Color b∗ index (psychometric yellow–blue chromaticness) was measured with 1 cm resolution using a Minolta CM-2002 color reflectance spectrophotometer.
AMS 14C dating
AMS 14C ages were measured in monospecific samples of the planktic foraminifera Neogloboquadrina pachyderma sinistral (N. pachyderma sin.) from the 125–250µm fraction, and benthic foraminifera Epistominella pacifica, and Uvigerina akitaensis from the 250–350µm fraction of the core. Five radiocarbon measurements were performed at the Keck Carbon Cycle AMS Facility (UCIAMS) in the Earth System Science Department of the University of California, USA. Two AMS 14C datasets measured in an AMS laboratory at the Atmosphere and Ocean Research Institute, University of Tokyo (Japan).
Conventional AMS 14C ages were calibrated to calendar ages using Calib 8.20 with the Marine20 calibration curve (Heaton et al., 2020) and the ΔR of 350 ± 40 years according to the reservoir age of the far NW Pacific equal to 900 years (Max et al., 2012).
Magnetic susceptibility
Sediment magnetic susceptibility was measured onboard using a Satis Geo KM-7 kappameter at a resolution of 1 cm. The sediment core was split and half of the core was used for magnetic susceptibility measurements.
XRF
The elemental composition of core LV63-41-2 was measured as peak area in counts per second at 0.5 cm resolution using the Itrax XRF core scanner at the First Institute of Oceanography, Ministry of Matural Resources, China. The Itrax XRF core scanner was set at 20 s count times, 30 kV X-ray voltage, and an X-ray current of 20 mA.
δ13Corg
The δ13Corg of marine sediment is a useful tracer for estimating the input of terrestrially derived organic carbon into the sediment. The δ13C of the organic carbon in the sediment, sampled every second centimeter with weights of 150-250 mg, were measured by the mass spectrometer Delta V Advantage in the laboratory of the Geochronology of the Cenozoic at the Institute of Archaeology and Ethnography (Novosibirsk, Russia). After removing carbonate by 10% HCl, CO2 was extracted from the sample by heating it at a temperature of 1020°C under a flow of high purity (6.0) helium. Values of δ13Corg were measured relative to the sucrose ANU standard with a similar extraction, with an accuracy of ±0.2‰.
Carbon-to-nitrogen ratio
The carbon-to-nitrogen (C/N) ratio may provide information about the origin of the preserved organic matter in the sediment. The content of carbon and nitrogen in the sediment was measured by the Euro EA (HEKAtech GmbH) analyzer in 1-2 mg samples by burning it at a temperature of 920°C under a flow of high purity helium in the laboratory of the Geochronology of the Cenozoic at the Institute of Archaeology and Ethnography (Novosibirsk, Russia). Urea STD PN33840002 (ThermoScientific) was used for calibration as a reference for the measurement of these elements. The precision of measured values was less than 1% for carbon and nitrogen.
Benthic foraminifera analysis
Benthic foraminifera were examined in 236 sediment samples at an interval of 1-2 or 4 cm. Benthic foraminifera were studied in sediment size fraction of more than 63 µm. Every specimen was counted and identified down to the species level using a stereo microscope ZEISS Stemi 2000-С. Benthic foraminifera abundance (BFA) expressed as the number of shells per 1 g of dry sediment (shells/g); species richness as the number of species per sample (species/sample), and the percentages of each species in the benthic foraminifera taxa assemblages were calculated.
Diatom analysis
One-centimeter slices of sediment sampled at 2-4 cm intervals were analyzed for diatom abundance, species richness, and species identification. Diatom abundance and taxon identification was performed using an Olympus BX-43 light microscope at 1000x. A total of 213 diatom species were found in 175 samples from the studied sediment. More than 300 diatom frustules were identified to the species level to obtain a special statistical distribution of the diatom assemblages. Sediment samples with very few diatom frustules were enriched using a heavy liquid technique to obtain the required statistical number of specimens. Diatom abundance expressed as the number of frustules per 1 g of dry sediment (fr./g); species richness as the number of species per sample (species/sample), and the percentages of each species in the diatom taxa assemblages were calculated.
Diatom sea ice group includes species habituated directly in sea ice or ice surfaces and present typical sea ice species of the Artic and subarctic regions such as Fragilariopsis oceanica (Cleve) Hasle, Fragilariopsis cylindrus (Grunow) Kreiger, Thalassiosira hyalina (Grunow) Gran, Thalassiosira kryophila (Grunow) Jørgensen and Thalassiosira nordenskioeldii Cleve.
Sea ice transported group includes allochthonous benthic and freshwater species, captured by sea ice on the shelf during winter ice formation, transported by surface water currents and dropped into bottom during ice melting. Benthic diatoms are represented by the genera Cocconeis, Delphineis, Diploneis, Navicula, etc. Freshwater diatoms are represented by the species Aulacoseira subborealis (Nygaard) Denus, Muylaert et Krammer and genera Amphora, Fragilaria, Pinnularia, Placoneis, Planctonella, Surirella, Cymbella, etc.
Pollen analysis
A total of 236 dry sediment samples with an average weight of 5-15 g were sampled every second cm from the studied core to investigate species distribution in the pollen assemblages. More than 300 pollen grains were calculated for species identification using a MICMED 6 microscope with amplification of 480x. Pollen grains were scarce in the core's lower part's sediment; however, the quantity required for statistical analysis was found in the core's upper part at 291 cm. Accordingly, species pollen compositions were determined for 81 samples, which is the required number of grains for statistical analysis.
Sample preparation for spore-pollen analysis was carried out according to standard methods, with treatment with 10% KOH followed by separation with a heavy liquid. The pollen groups of trees and shrubs, herbaceous plants, and spores were calculated as proportions of the total number of detected pollen microfossils, and the percentages of taxa within the tree, shrub, and spore groups were determined.
According to species distribution in the tree group, we calculated the pollen climatic index Kp as the ratio of the sum of heat-loving species to the sum of heat- and cold-loving taxa, following Igarashi and Oba (2006). We consider the Alnus, P. pumila, B. ermanii and Myrica taxa to be heat-loving, and the species Alnaster and B. sect. Nanae to be cold-loving.
Supplement to:
Gorbarenko, Sergey A; Shi, Xuefa; Malakhova, Galina Y; Bosin, Aleksandr A; Zou, Jianjun; Liu, Yanguang; Chen, Min-Te (2017): Centennial to millennial climate variability in the far northwestern Pacific (off Kamchatka) and its linkage to the East Asian monsoon and North Atlantic from the Last Glacial Maximum to the early Holocene. Climate of the Past, 13(8), 1063-1080, https://doi.org/10.5194/cp-13-1063-2017
Coverage:
Latitude: 51.570000 * Longitude: 160.017000
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Size:
12 datasets
Download Data
Datasets listed in this bundled publication
- Bosin, AA (2024): AMS 14C ages of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969075
- Bosin, AA (2024): Benthic foraminifera analysis of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969071
- Bosin, AA (2024): Carbon/nitrogen ratio of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969063
- Bosin, AA (2024): Calcium carbonate contents of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969054
- Bosin, AA (2024): Chlorin content of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969059
- Bosin, AA (2024): Color b∗ index of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969051
- Bosin, AA (2024): δ13C of organic carbon from sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969062
- Bosin, AA (2024): Diatom frustules of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969070
- Bosin, AA (2024): Diatoms of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969065
- Bosin, AA (2024): Magnetic susceptibility of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969061
- Bosin, AA (2024): Pollen analysis of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969074
- Bosin, AA (2024): X-ray fluorescence (XRF)-derived Ti/Ca record of sediment core LV63-41-2. https://doi.pangaea.de/10.1594/PANGAEA.969052