Gulf of Alaska, Northeast Pacific Geochemistry and Radiogenic Isotope Data from Leaching Experiments Du, J.; Haley, B.A.; Mix, A.C. Du, J. Haley, B.A. Mix, A.C. earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,"Marine sediment samples were collected using piston core ',' gravity core or multicore. Landfall volcanic ash samples were collected by hand. for the other type of cores it starts from the begining of the actually retrieved sediments.") earth science/paleoclimate/paleoceanography (depth at sample end,null,null,centimeter,null,paleoceanography,null,null,N,"For multicores the zero depth starts from the sediment water interface ',' for the other type of cores it starts from the begining of the actually retrieved sediments") earth science/paleoclimate/paleoceanography (calcium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (magnesium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (scandium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (dysprosium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (zinc,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (chromium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (samarium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (europium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (terbium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (neodymium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (erbium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (ytterbium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (longitude,null,null,degree east,null,paleoceanography,null,null,N,West negative) earth science/paleoclimate/paleoceanography (volume,null,null,milliliter,null,paleoceanography,null,null,N,volume of the diluted reagent; determined such that the solution vs solid ratio was approximately 8ml vs 1 g) earth science/paleoclimate/paleoceanography (epsilon neodymium,null,null,epsilon unit,null,paleoceanography,null,multiple collector inductively-coupled plasma mass spectrometry,N,eNd=((143Nd/144Nd)sample/(143Nd/144Nd)CHUR-1)*1E4) earth science/paleoclimate/paleoceanography (87Sr/86Sr,null,null,dimensionless,null,paleoceanography,null,multiple collector inductively-coupled plasma mass spectrometry,N,The 2 sigma external precision was calculated by running an in house standard repeadedly.) earth science/paleoclimate/paleoceanography (aluminum,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (copper,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (nickel,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (yttrium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (lanthanum,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (lutetium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,"Experiment code; Samples were freezed dried first and rinsed with ultrapure water three times before being leached using an acetic acid (abbreviated as AA) reagent or a hydroxylamine hydrochloride (abbreviated as HH) reagent. The AA reagent stock was made of 3.33 M AA buffered by Na-acetate to pH˜4. The HH reagent stock was made of 0.053 M HH in 2.62 M AA and buffered to pH˜4 by NaOH. In these leaching experiments, reagent concentration and leaching duration were varied. In experiments AA1 to AA3, the reagent concentration was fixed at 10% v/v of the stock but the leaching duration increased from 3 to 6 and 18 hour. In experiments HH1 to HH6, the leaching duration was fixed at 0.5 hour but the reagent concenetration increased from 5% to 10%, 20%, 30%, 40% and 50% v/v of the stock. In experiments HH7-HH11, the reagent concentration was fixed at 50% v/v of the stock but the leaching duration increased from 1 to 3, 6, 24 and 48 hours. Details see Du, Jianghui, Brian A. Haley, and Alan C. Mix. ""Neodymium isotopes in authigenic phases, bottom waters and detrital sediments in the Gulf of Alaska and their implications for paleo-circulation reconstruction."" Geochimica et Cosmochimica Acta 193 (2016): 14-35. HH4 is the final choice") earth science/paleoclimate/paleoceanography (depth at sample start,null,null,centimeter,null,paleoceanography,null,null,N,"For multicores the zero depth starts from the sediment water interface ',' for the other type of cores it starts from the begining of the actually retrieved sediments") earth science/paleoclimate/paleoceanography (barium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (cobalt,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (cerium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (thulium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (collection water depth,null,null,meter,null,paleoceanography,null,null,N,Positive below seafloor) earth science/paleoclimate/paleoceanography (potassium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (holmium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (sample identification,null,null,null,null,paleoceanography,null,null,C,Most of the samples are from sediment cores in the Gulf of Alaska but 4 of them are volcanic ash samples collected on land in 4 cities of the Washington State US after the 1980 Mt St. Helens eruption.) earth science/paleoclimate/paleoceanography (latitude,null,null,degree north,null,paleoceanography,null,null,N,South negative) earth science/paleoclimate/paleoceanography (strontium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (iron,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (manganese,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (vanadium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma atomic emission spectroscopy,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (weight,null,null,gram,null,paleoceanography,null,null,N,weight of freeze dried sample; approximately 1 gram) earth science/paleoclimate/paleoceanography (uranium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleoceanography (gadolinium,null,null,nanogram per gram,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,reported as ng leached from 1 g of freeze-dried sample) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (Gulf of Alaska and Northeast Pacific>LATITUDE >LONGITUDE ) The isotopic composition of neodymium (eNd) extracted from sedimentary Fe–Mn oxyhydroxide offers potential for reconstructing paleo-circulation, but its application depends on extraction methodology and the mechanisms that relate authigenic eNd to bottom water. Here we test methods to extract authigenic eNd from Gulf of Alaska (GOA) sediments and assess sources of leachate Nd, including potential contamination from trace dispersed volcanic ash. We show that one dominant phase is extracted via leaching of core-top sediments. Major and trace element geochemistry demonstrate that this phase is authigenic Fe–Mn oxyhydroxide. Contamination of leachate (authigenic) Nd from detrital sources is insignificant (<1%); our empirical results are consistent with established kinetic mineral dissolution rates and theory. Contamination of extracted eNd from leaching of volcanic ash is below analytical uncertainty. However, the eNd of core-top leachates in the GOA is consistently more radiogenic than bottom water. We infer that authigenic phases record pore water eNd, and the relationships of eNd among bottom waters, pore waters, authigenic phases and detrital sediments are primarily governed by the exposure time of bottom water to sea-floor sediments, rate of exchange across the sediment-water interface and the reactivity and composition of detrital sediments. We show that this conceptual model is applicable on the Pacific basin scale and provide a new framework to understand the role of authigenic phases in both modern and paleo-applications, including the use of authigenic eNd as a paleo-circulation tracer. STUDY NOTES: In this study we teste various leaching methods to extract authigenic iron manganese oxyhydroxides for neodymium isotope analysis from sediments in the Gulf of Alaska while avoiding contamination from lithogenic sedimenet components during chemical extractions. Method HH4 as described in the "Data" section is the final method of choice. This method was tested on a suite of core-top, down-core and marine ash layer samples from the Gulf of Alaska, as well as land fall volcanic ash samples from Mt St. Helens. We analyzed neodymium and strontium isotopes, major and trace elements, including the Rare Earth Elements, in the leachates and these data are reported here. Measurement precision- epsilon Nd: 0.37; 87Sr/86Sr: .000049; Aluminum,Barium,Calcium,Strontium,Iron,Manganese,Cobalt,Copper,Nickel,Zinc,Potassium,Magnesium,Vanadium,Chromium,Scandium, and Uranium: 5-10%; Yttrium,Lanthanum,Cerium,Praseodym,Neodymium,Samarium,Europium,Gadolinium,Terbium,Dysprosium,Holmium,Erbium,Thulium,Ytterbium,Lutetium: 5% Provided Keywords: neodymium isotopes, authigenic phase, Gulf of Alaska, North Pacific, core-top NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Du, J. Investigator : Haley, B.A. Investigator : Mix, A.C. 2017-06-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/22254 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/du2016/du2016.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/du2016/du2016.txt English https://www.ncdc.noaa.gov/paleo/study/22254 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/du2016/du2016.txt Du, Jianghui, Brian A. Haley, and Alan C. Mix2016Neodymium isotopes in authigenic phases, bottom waters and detrital sediments in the Gulf of Alaska and their implications for paleo-circulation reconstructionGeochimica et Cosmochimica Acta19314-3510.1016/j.gca.2016.08.005 -153.95 46.3 -117.43 60.66