1987 Compilation of Elemental Concentration Data for USGS BIR‐1, DNC‐1 and W‐2

Gladney, Ernest S.; Roelandts, Iwan

doi:10.1111/j.1751-908x.1988.tb00044.x

Cited by 89 publications

(45 citation statements)

References 20 publications

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“…Iron accounts for approximately ~3.5% (as Fe 2 O 3 ) of the upper continental crust (Taylor and McLennan, 1995), typical mid-ocean ridge basalt (N-MORB) contains ~9-10% iron (Viereck et al, 1989), whereas ocean island basalts (OIB) and continental flood basalts (CFB) have iron concentrations in the vicinity of 12-13% (Gladney and Roelandts, 1988;Marsh, 1987;Wilson, 1997a;Wilson, 1997b). While iron has oxidation states that range from -2 to +6, it occurs almost…”

Section: Iron In the Modern Oceanmentioning

confidence: 99%

Neoproterozoic iron formation: An evaluation of its temporal, environmental and tectonic significance

et al. 2013

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Neoproterozoic iron formation (NIF) provides evidence for the widespread return of anoxic and ferruginous basins during a time period associated with major changes in climate, tectonics and biogeochemistry of the oceans. Here we summarize the stratigraphic context of Neoproterozoic iron formation and its geographic and temporal distribution. It is evident that most NIF is associated with the earlier Cryogenian (Sturtian) glacial epoch. Although it is possible that some NIF may be Ediacaran, there is no incontrovertible evidence to support this age assignment. The paleogeographic distribution of NIF is consistent with anoxic and ferruginous conditions occurring in basins within Rodinia or in rift-basins developed on its margins. Consequently NIF does not require whole ocean anoxia. Simple calculations using modern day iron fluxes suggest that only models that invoke hydrothermal and/or detrital sources of iron are capable of supplying sufficient iron to account for the mass of the larger NIF occurrences. This conclusion is reinforced by the available geochemical data that imply NIF record is a mixture of hydrothermal and detrital components. A common thread that appears to link most if not all NIF is an association with mafic volcanics.Word Count: 11,011

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Section: Iron In the Modern Oceanmentioning

confidence: 99%

Neoproterozoic iron formation: An evaluation of its temporal, environmental and tectonic significance

et al. 2013

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“…This database was first modified by substituting FFAST values for all those elements found in major and minor quantities in the silicate reference materials. This required us to obtain FFAST MACs for every K X-ray emitted by the elements Z = 8, 11-17, 19-30 [10] Indian Indian Ocean: USNM 113716 2 [13] VG-A99 Makaopuhi Lava Lake, HI: USNM 113498-1 2 [13] VG-2 Juan de Fuca Ridge: USNM 111240-52 2 [13] Olivine Cape Ann Fayalite: Rockport, MA; USNM 85276 3 [13] San Carlos San Carlos, Gila Co., AZ: USNM 111312-444 2 [13] Pyrobole Px-1 Clinopyroxene: Libby, MT: Px-1 4 [14] Rhyolite Peru 215 Rhyolite: Muscani, Peru: RLS-215 1 [11] Mexico-132 Rhyolite: Tulancingo, Mexico: RLS-132 1 [11] Feldspar Or-1 Orthoclase: Adularia orthoclase: Val Cristallina, Switzerland: OR-1 4 [14] Lake Co. Plagioclase: Lake Co., OR: USNM 115900 3 [13] Albite Ab-1 Albite: Amelia Co. VA: Ab-1 4 [16] The rank describes the perceived degree of reliability of literature analyses available to the authors. in the absorbing elements Z = 8, 9, 11-17 and 19-30.…”

Section: Implementation Of New Mac Databases Within Gupixmentioning

confidence: 99%

“…We preferred to exclude EPMA-based analyses in view of the effects studied so much earlier by Smith et al [3] In terms of reliability that may be placed on the reported composition the highest rank was assigned in Table 1 to standards characterized by numerous methods. [10,11] The rationale adopted here was that a multitude of characterizations can mitigate the error caused by any one method that may be divergent. Those standards that have undergone several analyses [12] by chemical methods at the Smithsonian Institute by Jarosewich et al [12,13] were accorded the second rank in the table.…”

Section: Introductionmentioning

confidence: 99%

Choice of X‐ray mass attenuation coefficients for PIXE analysis of silicate minerals and rocks

2015

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The accuracy of each of three mass attenuation coefficient databases was assessed using particle-induced X-ray emission measurements performed on well-characterized, homogeneous silicate glass and mineral standards. In a fundamental parameters computation, the absolute efficiency constants of the light elements Mg, Al and Si, found within each standard, were determined. These were compared with the efficiency constants deduced from separate particle-induced X-ray emission measurements performed on pure targets of the same three elements. In this comparison, a 7-9% discrepancy was found when using the XCOM database for the computation, but this was reduced to 2-5% when FFAST coefficients were substituted. Further improvement was achieved when a hybrid database was adopted. This 'Mixed' database consisted of primarily XCOM coefficients with FFAST values inserted for the light element (Z = 11,…, 14) attenuation of photons having energy less than their K edge and for oxygen in the 1-2 keV range. The average efficiency constant discrepancies were reduced to À0.5-2%.

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“…For identifying outlying observations, the measurements outside the two standard deviation of the sample mean ( s x 2 ± ) were deleted. This simple population-based method has been used later by others for processing the geochemical data for rock reference materials (e.g., Gladney, 1981;Gladney and Roelandts, 1988;Gladney et al, 1990Gladney et al, , 1991Imai et al, 1996). Such fixed multiples of standard deviation methods, such as the two standard deviation method, have been criticised in the literature (Barnett and Lewis, 1994;Verma, 1997Verma, , 1998Verma, , 2005Quiroz-Ruiz, 2006a, b, 2008;Hayes et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

IAEA inter-laboratory comparisons of geothermal water chemistry: critiques on analytical uncertainty, accuracy, and geothermal reservoir modelling of Los Azufres, Mexico

Verma

2013

Journal of Iberian Geology

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The results of International Atomic Energy Agency (IAEA) inter-laboratory comparison program reported in the literature during 1992 and 2004 were analyzed to estimate analytical uncertainty in the geochemical analysis of geothermal waters. Statistical data treatments for the detection and elimination of outliers and extremums were performed using five methods: (i) data visualization (or raw data statistics); (ii) mean ( x ) and standard deviation (s) calculation after eliminating outliers with s x 2 ± ; (iii) median and median absolute difference (MAD); (iv) Huber method; and (v) single-outlier type multiple test method involving Dixon, Grubbs, skewness and kurtosis tests at 99% confidence level. The results are reported in scientific notation with one significant digit of uncertainty. A comparative study of all the five statistical data treatment methods suggests that the fifth method provides better results for the statistical analysis of experimental measurements. A preliminary evaluation for the analytical accuracy of geochemical analysis of geothermal waters, prepared by dissolving 4.585 g CaCl 2 (98.2%), 16.5 g NaCl (99.9%), 3.58 g MgCl 2 (99.0%), 0.74 g Na 2 SO 4 (99.0%) and 0.95 g KCl (99.5%) in 1 liter of solution, is presented. 2-and Cl -are probably associated with the sample preparation. The relations between the coefficient of variation (i.e. % analytical uncertainty) and concentration of each element are derived, which are used for the propagation of uncertainty in the geochemical calculations of geothermal systems. The uncertainty propagation procedure is illustrated in the calculation of Los Azufres geothermal reservoir temperature and vapor fraction. The uncertainty in the estimated temperature is ±20 K, which means that the changes in the geothermal reservoir fluid characteristics during its exploitation are generally within the uncertainty.Keywords: analytical accuracy, DODESSYS, geothermal waters, Inter-laboratory comparison, statistical data treatment, uncertainty propagation. ResumenLos resultados del programa de comparación inter-laboratorios del Organismo Internacional de Energía Atómica (OIEA), reportados en la literatura durante el período 1992 y 2004, han sido analizados para estimar la incertidumbre en los análisis geoquímicos de las aguas geotérmicas. Se realizó el tratamiento estadístico de los datos para la detección y eliminación de valores atípicos y 58

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1987 Compilation of Elemental Concentration Data for USGS BIR‐1, DNC‐1 and W‐2

Cited by 89 publications

References 20 publications

Neoproterozoic iron formation: An evaluation of its temporal, environmental and tectonic significance

Neoproterozoic iron formation: An evaluation of its temporal, environmental and tectonic significance

Choice of X‐ray mass attenuation coefficients for PIXE analysis of silicate minerals and rocks

IAEA inter-laboratory comparisons of geothermal water chemistry: critiques on analytical uncertainty, accuracy, and geothermal reservoir modelling of Los Azufres, Mexico

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