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opencc-by-4.0Aug 2019View details →

Geochemical evidence for high volatile fluxes from the mantle at the end of the Archean: Sample data

This file describes the origin of samples and gives the original xenon data published in refs. 4, 5 and 8. The slopes of the fractionation lines are given in refs. 8 (Table S1), 5 (Tables 1 and S1) and 4 (Table S1). For the barite sample (Ref. 6, Table 1), Xe data were normalized to 132Xe since 130Xe could have been contributed by radioactivity products. In this case Δ129Xe was computed from 128Xe and 131,132Xe data. The Δ129Xe values were computed from the difference between the isotope fractionation slope (&permil;/u) and the 129Xe/130Xe values in deviation permil (&permil;) relative to the corresponding atmospheric isotope composition.

opencc-by-4.0Mar 2009View details →

Fig. 3 in Nanostructural and geochemical features of the Jurassic isocrinid columnal ossicles

Fig. 3. Distribution of Mg/Ca and Sr/Ca in columnal plate of Chariocrinus andreae (Desor, 1845) from Gnaszyn clay pit, Poland (ZPAL Ca.7/1) obtained by NanoSIMS ion microprobe mapping (A, B, D, E). Line scans extracted from the images (C, F; "S" = start and "E" = end; vertical bars represent standard error). Note a sharp geochemical boundary between inter−stereom deposits and the stereom and heterogenous distribution of Mg in stereom with higher concentrations in the middle−zone of the skeletal bar. There is also clear difference between Sr content between inter−sterom deposits and stereom, however, due to low count rate, any possible differences within the stereom bar cannot be resolved.

opencc-by-4.0Mar 2009View details →

Fig. 2 in Nanostructural and geochemical features of the Jurassic isocrinid columnal ossicles

Fig. 2. Micro− and nanostructural organization and basic geochemical characteristics of the Middle Jurassic (Middle Bathonian) isocrinid columnals from Gnaszyn clay pit, Poland. A. Transverse section of the columnal (beige in color) of Chariocrinus andreae (Desor, 1845), GIUS 8−2570 (A2 enlargement) in optical microscope (A1, A2) and in SEM back−scattered electron (BSE; A6, A7) images. Nanogranular organization of the stereom in AFM images (A4, A9 height−2D, and A5, A10 deflection images respectively; contact mode; buffered pH = 8, ammonium persulfate 1%, 10 min.). B. Slightly oblique section of the columnal (black in color) of Balanocrinus berchteni Hess and Pugin 1983, GIUS 8−2510 (B2 enlargement) in optical microscope (B1, B2) and in BSE (B6–B8) images. Note a clear border between stereom with distinct nanogranular texture and inter−stereom deposits with more flat surface (parallel lines are polishing scratches); B4, B10 height, and B5, B11 phase images, respectively. BSE mode enhances atomic number contrast; elements with lower atomic numbers appear darker, those with higher atomic numbers appear lighter (e.g., framboidal pyrite grains, B7). Spot geochemical analyses of the stereom (A3, B3) and inter−stereom deposits (A8, B9).

opencc-by-4.0Mar 2009View details →

Fig. 1. A in Nanostructural and geochemical features of the Jurassic isocrinid columnal ossicles

Fig. 1. A. Simplified map of Poland with position of investigated Gnaszyn locality. B. Enlargement of Gnaszyn area with a clay pit from which crinoid samples were collected (modified after Zatoń et al. 2006). C. Stratigraphic column of the Bathonian deposits at Gnaszyn clay pit (modified after Majewski 2000).

Fig. 7. Trace element environmental proxies for the F–F in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 7. Trace element environmental proxies for the F–F transition in the Syv'yu River section. Bio−productivity tracers* are normalized according to Schmitzetal.(1997).DownwardarrowedtrendsarebasedonthesinglesampleCB99−222,located2.15mbelow;recognizedMo/Alenrichment,indicative of anoxic−sulfidic deposition, is shown as well. For explanations see Fig. 4.

Fig. 6 in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 6. Various upper Frasnian spongiolitic microfacies, Syv'yu River section. A. Sponge boundstone(?); note large growth cavities, and complex and diverse, peloidal to bioclastic geopetal fill up, as well as preserved spicular network; sample Syv96−58. B, C. Sponge relics (Sp) distinguished by a variety of grumeous fabric, pyrite−rich marginal rims, and partly chertified interstitial mudstone matrix (Ch); samples CB99−224 (B) and CB99−314 (C).

Fig. 1 in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 1. Location of the studied area in Russia (A) and Timan−Pechora region (B, modified from Becker et al. 2000: fig. 1A), and location of the Kozhym River basin (C) and locality map of studied outcrops along the Syv'yu River section (D), western slopes of the Subpolar Urals; C1t, Tournaisian. D1, Lower Devonian; D2tk,?Middle Devonian, Takata Suite; D2ef−gv, Eifelian–Givetian; D3fr, Frasnian; D3fm, Famennian.

Fig. 4 in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 4. Upper Frasnian and lower Famennian lithologic column of the Syv'yu River section (upper Vorota Fm.), sampling pattern and conodont succession across the F–F boundary, with emphasis on principal biotic events and alleged Kellwasser levels (see also Figs. 7, 8); figures in the lithological column refer to microfacies photos (Figs. 5, 6).

Fig. 2. F–F in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 2. F–F boundary beds exposed along the right bank of Syv'yu River, outcrop 2 (line marks F–F boundary; for location see Fig. 1D).

Fig. 8 in The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records

Fig. 8. Stable isotope geochemistry for the Upper Frasnian and lower Famennian in the Syv'yu River section, F–F background values taken from Joachimski and Buggisch (1996: fig. 1); for explanations see Fig. 4.

opencc-by-4.0Sep 2024View details →

Dataset for Gion et al. (2024) - "The Geochemical Behavior of Scandium in Magmatic Systems"

Datasets for Gion et al. (2024) - "The Geochemical Behavior of Scandium in Magmatic Systems". Files include all datasets and code used for modeling.

opencc-by-4.0Nov 2024View details →

National Geochemical Survey of Australia: Samarium-Neodymium Isotopes Dataset

Preamble -- The 'National Geochemical Survey of Australia: The Geochemical Atlas of Australia' was published in July 2011 along with a digital copy of the NGSA geochemical dataset (<a href="http://dx.doi.org/10.11636/Record.2011.020" target="_blank" rel="noopener">http://dx.doi.org/10.11636/Record.2011.020</a>). The NGSA project is described here: <a href="http://www.ga.gov.au/ngsa" target="_blank" rel="noopener">www.ga.gov.au/ngsa</a>. A recent review of the original and ensuing NGSA outputs and impacts can be found in Caritat (2022). The present dataset contains additional geochemical data obtained on NGSA samples: Samarium-Neodymium Isotopes Dataset.  Abstract -- Ninety three coarse-fraction (<2 mm) Bottom Outlet Sediment (BOS, on average 60 – 80 cm depth) NGSA samples mostly from three continental-scale cross-sections (one central north-south cross-section, one central east-west, and one southern east-west) were analysed for the samarium (Sm) and neodymium (Nd) isotopes 147Sm, 143Nd, and 144Nd to determine the 143Nd/144Nd and 147Sm/144Nd isotope ratios, initial epsilon Nd (εNd0), and single and two-stage depleted mantle model ages TDM and T2DM (in Ga or billion years). Together these samples represent over 490,000 km2 of catchment area sourcing the sampled fluvial/alluvial sediments. The summary statistics for 143Nd/144Nd and εNd0 results are shown below. <table> <tbody> <tr> <td>Stats</td> <td>143Nd/144Nd</td> <td>εNd0</td> </tr> <tr> <td>Min</td> <td>0.511014</td> <td>-31.68</td> </tr> <tr> <td>25%</td> <td>0.511550</td> <td>-21.22</td> </tr> <tr> <td>Median</td> <td>0.511817</td> <td>-16.02</td> </tr> <tr> <td>MAD</td> <td>0.000232</td> <td>4.53</td> </tr> <tr> <td>Average</td> <td>0.511802</td> <td>-16.31</td> </tr> <tr> <td>SD</td> <td>0.000342</td> <td>6.67</td> </tr> <tr> <td>75%</td> <td>0.512019</td> <td>-12.07</td> </tr> <tr> <td>Max</td> <td>0.512623</td> <td>-0.29</td> </tr> </tbody> </table> The method is briefly summarised below. Samples were analysed at University of Melbourne (UOM) by Roland Maas and University of Alberta (UOA) by Rob Creaser. At UOM all analyses were by isotope dilution. Samples were dissolved at high pressure, and Sm and Nd extracted using Eichrom TRU- and LN-resin columns. Isotopic analyses were by Multi Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS), with Nd mass bias corrected by internal normalisation to 146Nd/145Nd = 2.0719425 (equivalent to 146Nd/144Nd = 0.7219). In-run errors (2se) were ± 0.000010 or lower, external precision (2sd) ± 0.000020. All 143Nd/144Nd results have been adjusted to LaJolla=0.511860. The TIMS reference for JNd-1 is 0.512117, and BCR-2 has a nominal 147Sm/144Nd of 0.1382 and 143Nd/144Nd of 0.512640 ± 20. At UOA rock powders were accurately weighed and totally spiked with a known amount of mixed 150Nd-149Sm tracer solution and dissolved at high pressure for 5 days. Sm and Nd were extracted and separated by conventional cation and HDEHP-based chromatography (Creaser et al., 1997). Chemical processing blanks were < 120 picograms of either Sm or Nd, and are insignificant relative to the amount of Sm or Nd analysed for any rock sample. Isotopic analyses were determined in static mode by MC-ICP-MS (Schmidberger et al., 2007). All isotope ratios were normalized for variable mass fractionation to a value of 146Nd/144Nd = 0.7219. The 143Nd/144Nd ratio of samples are presented here relative to a value of 0.511850 for the La Jolla Nd isotopic standard, monitored by use of an in-house Alfa Nd isotopic standard for each analytical session. Sm isotopic abundances were normalized for variable mass fractionation to a value of 1.17537 for 152Sm/154Sm. The mixed 150Nd-149Sm tracer solution used was calibrated directly against the Caltech mixed Sm/Nd normal described by Wasserburg et al. (1981). Using this mixed tracer, the measured 147Sm/144Nd ratios for the international rock standard BCR-1 ranged from 0.1380 to 0.1382, suggesting a reproducibility for 147Sm/144Nd of ~ ± 0.1 % for real rock powders. The value of 147Sm/144Nd determined for BCR-1 was within the range of reported literature values by isotope dilution methods. A full report on this dataset will be available shortly as a Geoscience Australia Record. REFERENCES CITED Caritat, P. de, 2022. The National Geochemical Survey of Australia: review and impact. Geochemistry: Exploration, Environment, Analysis, 22, geochem2022-032. <a href="https://doi.org/10.1144/geochem2022-032">https://doi.org/10.1144/geochem2022-032</a> Creaser, R.A., Erdmer, P., Stevens, R.A. and Grant, S.L., 1997. Tectonic affinity of Nisutlin and Anvil assemblage strata from the Teslin tectonic zone, northern Canadian Cordillera: constraints from neodymium isotope and geochemical evidence. Tectonics, 16, 107-121. <a href="https://doi.org/10.1029/96TC03317" target="_blank" rel="noopener">https://doi.org/10.1029/96TC03317</a>  Schmidberger, S.S., Heaman, L.M., Simonetti, A., Creaser, R.A. and Whiteford, S., 2007. Lu-Hf, in-situ Sr and Pb isotope and trace element systematics for mantle eclogites from the Diavik diamond mine: evidence for Paleoproterozoic subduction beneath the Slave craton, Canada. Earth and Planetary Science Letters, 254, 55-68. <a href="https://doi.org/10.1016/j.epsl.2006.11.020" target="_blank" rel="noopener">https://doi.org/10.1016/j.epsl.2006.11.020</a>  Wasserburg, G.J., Jacobsen, S.B., DePaolo, D.J., McCulloch, M.T. and Wen, T., 1981. Precise determination of Sm/Nd ratio, Sm, Nd isotopic abundances in standard solutions. Geochimica et Cosmochimica Acta, 45, 2311-2323.

FIG. 1. — A in Mammal bearing late Miocene tuffs of the Akkaşdağı region; distribution, age, petrographical and geochemical characteristics

FIG. 1. — A, location map and major structural features of Turkey with location of Oligocene to Quarternary volcanism; B, map of the area SW of Çankırı-Çorum Basin (modified from Bilgin et al. 1986). Abbreviations: CAVP, Central Anatolian Volcanic Province; WAVP, West Anatolian Volcanic Province; EAVP, East Anatolian Volcanic Province; GVC, Galatia Volcanic Complex; NAFZ, North Anatolian Fault Zone; EAFZ, East Anatolian Fault Zone; BSZ, Bitlis Suture Zone; EFZ, Ecemis Fault Zone; KEF, Kırıkkale Erbaa Fault.

FIG. 3 in Mammal bearing late Miocene tuffs of the Akkaşdağı region; distribution, age, petrographical and geochemical characteristics

FIG. 3. — Representative photomicrographs of the studied tuffs; A, B, vitric tuff of upper level (cross-plane polarized light); C, D, vitric tuff of lower level (cross-plane polarized light); E, F, vitric tuffs consisting of an abundant glassy material, feldspar (Fl) and hornblend (Hb) (cross-plane polarized light); G, pumice clast (Pm) and oxyhornblend (Hn) (plane polarized light); H, rhyolitic lavas found at two levels in tuffs are completely calcified (cross polarized light). Abbreviations: Bi, biotite; Lt, lithic clast. Scales bars: A-D, G, H, 0.7 mm; E, F, 0.4 mm.

FIG. 5. — Integrated 39 in Mammal bearing late Miocene tuffs of the Akkaşdağı region; distribution, age, petrographical and geochemical characteristics

FIG. 5. — Integrated 39Ar/40Ar ages for two samples from the Akkaşdağı tuffs; A, sample AKK-1 from the main tuff horizon, three meters below the bone pocket AK-5; B, sample AKK-2 from the reworked tuffs filling the bone pocket AK-5.

FIG. 4. — A in Mammal bearing late Miocene tuffs of the Akkaşdağı region; distribution, age, petrographical and geochemical characteristics

FIG. 4. — A, total alkali vs. SiO2 diagram for the studied tuffs and Nevşehir Plateau ignimbrite. Classification scheme is from Le Bas et al. (1986), with the alkaline-subalkaline line by Miyashiro (1978); B, AFM diagram is from Irwine & Baragar (1971); C, Hacker variation diagrams for the studied tuffs and Nevşehir Plateau ignimbrite.

opencc-by-4.0Nov 2022View details →

Carbon-isotope, geochemical, and biostratigraphic data from the Anchor 3 well, Green Canyon protraction area, Gulf of Mexico

Dataset that accompanies "Carbon-isotope chemostratigraphy, geochemistry, and biostratigraphy of the Paleocene-Eocene Thermal Maximum, deep-water Wilcox Group, Gulf of Mexico (U.S.A.)" To be submitted to Climate of the Past

opencc-by-4.0Mar 2023View details →

LILBID spectra and geochemical data shown in article "Detection of Phosphates Originating from Enceladus' Ocean" by Frank Postberg et al. (2023)

Laser Induced Liquid Beam Ion Desorption (LILBID) mass spectra of phosphates and data of geochemical experiments, shown in article "Detection of Phosphates Originating from Enceladus’ Ocean" by Frank Postberg et al. (2023), published in Nature.