0000000000280411
AUTHOR
Jonathan E. Snow
MPI-DING reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios
We present new analytical data of major and trace elements for the geological MPI-DING glasses KL2-G, ML3B-G, StHs6/80-G, GOR128-G, GOR132-G, BM90/21-G, T1-G, and ATHO-G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA-ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Associ…
Constraints on Earth accretion deduced from noble metals in the oceanic mantle
If the Earth's mantle were in equilibrium with its core, the mantle would contain three orders of magnitude less of the noble metals (platinum-group elements Pt, Os, Ir, Ru, Pd and Rh, plus Au and Re) than are observed. An explanation put forward to account for this disparity has been that the last 1% of the Earth's accretion occurred after the iron-rich core had separated from the mantle1,2. Recent debate has accordingly centred on which meteorite class or classes made up this ‘late veneer’ of accretion3. Here we present analyses of noble-metal concentrations in oceanic peridotites (plutonic rocks which are thought to represent samples of the Earth's upper mantle). We find that the average…
Os isotopes and highly siderophile elements (HSE) in the Ligurian Ophiolites, Italy.
The Os isotopic and highly siderophile element (HSE) concentration systematics of the upper mantle have been the focus of much recent interest. However, little systematic study has addressed the combined HSE and Os isotopes in mantle rocks from MOR ophiolites. The Ligurian ophiolites in northern Italy represent an important class of ophiolites representing, like Zabargad or the Galicia margin, crust with clear ocean ridge affinity floored by older mantle with arguably more continental affinities [Rampone et al., J. Petrol. 36, 18–105, 1995; Rampone et al., Contrib. Mineral. Petrol. 123, 61–67, 1996]. We have studied a suite of 15 geochemically and geologically well characterized mantle peri…