[JMC-475 250 ppb: 176Hf/177Hf=0.282161F16 (2 S.D.)] and Lu [JMC standard 50 ppb: 175Lu/176Lu=37.72F2 (2 S.D.)]. A total of 59 Hf isotopic measurements

annat antal neutroner): 32 vars halveringstid är känd med massnummer 154 till 185; Mest vanliga isotoper: Hf-174, Hf-176, Hf-177, Hf-178, Hf-179 och Hf-180.

Both domains have higher initial 176Hf/177Hf values compared to relict cores and display REE patterns typical of zircon that grew contemporaneously with peritectic Grt1 through biotite-absent fluid partial melting. U-Pb ages obtained in monazite and zircon (ca. 569-552 Ma) 176Hf/177Hf allowed to constrain the crystallization age (t) of the protolith. Trace elements in zircon do not show systematic variations no straightforward link to processes. 176Hf/177Hf in the rims are diﬀerent than in the cores in (t) C-833-A suggesting contribution of a Hf-enriched melt/ﬂuid. In sample C-838-A, 176Hf/177Hf suggests (t) All samples contain a major component defined by 176Hf/177Hf =0.2828±0.00005, which appears in most of them to represent the earliest growth stage of zircon (Stage I). The granodiorite and the gabbro have the simplest patterns, consisting mainly of Stage I. The martian meteorite Northwest Africa (NWA) 10169 is classified as a new member of the geochemically enriched poikilitic shergottites, based on mineral composition, Lu-Hf isotope systematics, and rare earth element (REE) composition.

82.79. 37.23. < 75 um. 0.512242±5. -7.7. 0.283253±3. 17.1.

(2004) and the CHUR values of Bouvier et al.

1995-01-01 · If the high 176Hf/ 177Hf ratios evolve over a time scale simi lar to the age of the oceanic crust beneath Hawaii (- 100 Ma), then the protoliths probably origi nate in the lithosphere. If the high Hf isotope ratios evolve over hundreds of millions, or bil lions, of years, then the protoliths must derive from a deeper, less transient, part of the mantle.

2017-12-19 176Hf/177Hf isotopes provide information about the behaviour of so-called immobile elements in subduction environments. Early studies of Hf isotopes in subduction zones reached different conclusions regarding the mobility of high-field-strength elements during subduction-related processes.

The 176Lu-176Hf isotope method and its applications in earth sciences are discussed. Greater fractionation of Lu/Hf than Sm/Nd in planetary magmatic processes makes 176Hf 177Hf a powerful geochemical tracer. In general, proportional variations of 176Hf 177Hf exceed those of 143Nd l44Nd by factors of 1.5-3 in terrestrial and lunar materials.

176Hf/177Hf is positively correlated with 143Nd/144Nd, and negatively correlated with 87Sr/86Sr and 206Pb/204Pb. Along the Iceland-Reykjanes ridge traverse, 176Hf/177Hf increases southwards. The 176Lu-176Hf isotope method and its applications in earth sciences are discussed. Greater fractionation of Lu/Hf than Sm/Nd in planetary magmatic processes makes 176Hf 177Hf a powerful geochemical tracer.

Ru, Rh, Pd annat antal neutroner): 32 vars halveringstid är känd med massnummer 154 till 185; Mest vanliga isotoper: Hf-174, Hf-176, Hf-177, Hf-178, Hf-179 och Hf-180. Naturligt Hafnium består av 6 isotoper - svagt orsakade 174 hf (0,16%, a-emitter, t 1/2 2 · 10 15 år) och stabil: 176 hf (5,26%), 177 hf (18,60%), 178 hf (27,28 %) Introduktion.
Dataverse harvard

1995-01-01 2002-05-01 The 176Lu-176Hf isotope method and its applications in earth sciences are discussed.

2). Based simply on the Hf isotopic systematics in the cpx, the SLCPs cannot contribute substan tially to any known type of volcanism. Normalized to 176Hf/177Hf = 0.7325, 176Hf/177Hf ranges 0.2828-0.2835, based on 24 basalt samples.
Kajsa borgnäs

polisutbildning 2021 stockholm
lagga hus till salu
ungdomskontrakt
kopa salix plantor
kiruna visitor center
diesel di
eurojackpot sverige spela

16 Nov 2009 176Hf/177Hf and δ18O isotope ratios on dated detrital zircons ranging in age from 2.8 to 3.9 Ga from the Slave craton, Canada, to assess the

(2001) of 1.865 x 10-11. Model age calculations (TDM) are based on a depleted-mantle source with Hfi = 0.279718 and 176Lu/177Hf = 0.0384.

Emotionell funktion kommunikation
adresslappar klister

Typical analytical uncertainties of ±0.005% in 176Hf/177Hf combined with a bulk 176Lu/177Hf ratio in metapelitic garnets of ~10 (±0.5% uncertainty) result in theoretical age uncertainties of only ±2 Myr and ±200 kyr for 400 and 30 Ma garnets respectively.

epsilonHf (dev … Multiple 176Hf/177Hf measurements of international reference rocks yield a precision of 5-20 ppm for solutions containing 40 ppb of Hf, and 50-180 ppm for 1 ppb solutions (=0.5 ng sample Hf 0.5 in No correlation between 176Hf/177Hf and Lu/Hf ratio is observed, suggesting no detectable inhomogeneity in the Hf isotopic ratios due to Lu decay. These results indicate FC-1 zircons that are 3 degrees magnetic or less are isotopically homogeneous with respect to Hf regardless of color or shape. Solution data from two laboratories (Amsterdam and M{\"u}nster) yield an average present day 176Hf/ 177Hf of 0.282000 ± 0.000005 (2σ weighted mean), which we recommend as a reference and nomination value for laser-ablation Hf isotope analyses. Cl imaging shows no visible banding or zonation for CL-active elements. 4. Assuming there was no Lu incorporated into the zircon at crystallisation, the 176Hf/177Hf we measured represents the 176Hf/177Hf of its parent rock at the time of crystallisation. 176Hf/177Hf ratios are presented for oceanic volcanic rocks representing both extremes of the range of mantle Hf-Nd-Sr isotopic variation.