Data Description

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Citation:
Bory, Aloys J-M; Wolff, Eric W; Mulvaney, Robert; Jagoutz, Emil; Wegner, Anna; Ruth, Urs; Elderfield, Henry (2010): (Appendix A) Geochemical composition of snow and eolian mineral dust from Berkner Island ice sheet, Antarctica. doi:10.1594/PANGAEA.786617,
Supplement to: Bory, Aloys J-M; Wolff, Eric W (2010): Multiple sources supply eolian mineral dust to the Atlantic sector of coastal Antarctica: Evidence from recent snow layers at the top of Berkner Island ice sheet. Earth and Planetary Science Letters, 291(1-4), 138-148, doi:10.1016/j.epsl.2010.01.006
Abstract:
The Sr and Nd isotopic composition of dust extracted from recent snow layers at the top of Berkner Island ice sheet (located within the Filchner-Ronne Ice Shelf at the southern end of the Weddell Sea) enables us, for the first time, to document dust provenance in Antarctica outside the East Antarctic Plateau (EAP) where all previous studies based on isotopic fingerprinting were carried out. Berkner dust displays an overall crust-like isotopic signature, characterized by more radiogenic 87Sr/86Sr and much less radiogenic 143Nd/144Nd compared to dust deposited on the EAP during glacial periods. Differences with EAP interglacial dust are not as marked but still significant, indicating that present-day Berkner dust provenance is distinct, at least to some extent, from that of the dust reaching the EAP. The fourteen snow-pit sub-seasonal samples that were obtained span a two-year period (2002-2003) and their dust Sr and Nd isotopic composition reveals that multiple sources are at play over a yearly time period. Southern South America, Patagonia in particular, likely accounts for part of the observed spring/summer dust deposition maxima, when isotopic composition is shifted towards 'younger' isotopic signatures. In the spring, possible additional inputs from Australian sources would also be supported by the data. Most of the year, however, the measured isotopic signatures would be best explained by a sustained background supply from putative local sources in East Antarctica, which carry old-crust-like isotopic fingerprints. Whether the restricted East Antarctic ice-free areas produce sufficient eolian material has yet to be substantiated however. The fact that large (> 5 µm) particles represent a significant fraction of the samples throughout the entire time-series supports scenarios that involve contributions from proximal sources, either in Patagonia and/or Antarctica (possibly including snow-free areas in the Antarctic Peninsula and other areas as well). This also indicates that additional dust transport, which does not reach the EAP, must occur at low-tropospheric levels to this coastal sector of Antarctica.
Project(s):
Coverage:
Latitude: -79.566700 * Longitude: -45.650000
Minimum DEPTH, ice/snow: 0.0 m * Maximum DEPTH, ice/snow: 1.0 m
Event(s):
BER01S03 (Thyssenhoehe) * * Latitude: -79.566700 * Longitude: -45.650000 * Date/Time: 2003-12-01T00:00:00 * Elevation: 899.0 m * Location: Berkner Island (Thyssenhöhe) * * Device: Snow pit *
Comment:
87Sr/86Sr error bars span the entire possible 87Sr/86Sr range taking into account a potential carbonate contribution varying from 0 to 100% (and associated errors), in addition to the analytical measurement 2 sigma error and errors on sea-salt derived Sr estimates.
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Sample ID *IDBory, Aloys J-M *
2Sample type *Samp typeBory, Aloys J-M *
3Depth, top/min *Depth topmBory, Aloys J-M *
4Depth, bottom/max *Depth botmBory, Aloys J-M *
5DEPTH, ice/snow *Depth ice/snowmGeocode
6Sample mass *Samp mgBory, Aloys J-M *
7Time coverage *CoverageBory, Aloys J-M *estimated corresponding time slice
8delta 18O, water *d18O H2Oper mil SMOWBory, Aloys J-M *Thermal Ionization Mass Spectrometry (TIMS) *soluble fraction
9Sodium *Na+mg/lBory, Aloys J-M *Ion chromatography *soluble fraction
10Calcium *Ca2+mg/lBory, Aloys J-M *Ion chromatography *soluble fraction
11Neodymium *Ndrelative unitsBory, Aloys J-M *total yield from particulate fraction in ng
12Dust concentration *Dust concg/kgBory, Aloys J-M *estimated from Nd, assuming 25 ppm Nd in the dust
13Neodymium 143/Neodymium 144 *143Nd/144NdBory, Aloys J-M *Thermal Ionization Mass Spectrometry (TIMS) *particulate fraction
14Neodymium 143/Neodymium 144, error *143Nd/144Nd eBory, Aloys J-M *
15epsilon-Neodymium (0) *e-Nd(0)Bory, Aloys J-M *particulate fraction
16epsilon-Neodymium, standard deviation *e-Nd std devBory, Aloys J-M *
17Strontium 87/Strontium 86 *87Sr/86SrBory, Aloys J-M *Thermal Ionization Mass Spectrometry (TIMS) *particulate fraction
18Strontium 87/Strontium 86, error *87Sr/86Sr eBory, Aloys J-M *+ 2 sigma
19Strontium 87/Strontium 86, error *87Sr/86Sr eBory, Aloys J-M *- 2 sigma
License:
Size:
250 data points

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