Sulfidic formations in deep xenoliths from kimkerlite pipes in Yakutia

Vakhrushev, V.A.; Sobolev, N. V.

doi:10.1080/00206817309475859

Cited by 10 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There does not appear to be any desulfurization leading to Fe or FeNi alloys in any of the xenolith suites studied (Meyer and Boctor, 1975;Vakhrushev and Sobolev, 1973;Desborough and Czmanske, 1973). Moody (1976), summarizing available pressure-temperature-oxygen fugacity conditions for serpentinization concludes that the process will take place in the middle to upper parts of the crust.…”

mentioning

confidence: 99%

The Moho as a magnetic boundary

Wasilewski

Thomas

Mayhew

1979

Geophysical Research Letters

223

View full text Add to dashboard Cite

Mantle derived rocks — peridotites from St. Pauls rocks, dunite xenoliths from the Kaupulehu flow in Hawaii, as well as peridotite, dunite, and eclogite xenoliths from Roberts Victor, Dutoitspan, Kilbourne Hole, and San Carlos diatremes — are weakly magnetic at room temperature. Saturation magnetization values range from 0.013 emu/gm to <0.001 emu/gm equivalent to ∼0.01 to 0.001 wt % Fe3O4. A review of pertinent literature dealing with analysis of the minerals in mantle xenoliths provides evidence that metals and primary Fe3O4 are absent, and that complex Cr, Mg, Al, Fe spinels dominate the oxide mineralogy. These spinels would be non‐magnetic at mantle temperatures. The crust/mantle boundary can be specified as a magnetic mineralogy discontinuity. Curie depth estimates from aeromagnetic anomalies do not require a source of magnetization in the mantle. All of the available evidence supports the new magnetic results, indicating that the seismic Moho is a magnetic boundary. The source of magnetization is in the crust and the maximum Curie isotherm depends on the type of magnetic mineralogy and is located at depths which will vary with the regional geothermal gradient.

show abstract

mentioning

confidence: 99%

The Moho as a magnetic boundary

Wasilewski

Thomas

Mayhew

1979

Geophysical Research Letters

223

View full text Add to dashboard Cite

show abstract

“…For nearly half a century, BMS have been identified in a number of mantle-derived materials, including: peridotite and pyroxenite xenoliths entrained in basaltic and kimberlitic rocks ( Fig. 1; e.g., Meyer and Brookins 1971; Desborough and Czamanske 1973;Frick 1973; Vakhrushev and Sobolev 1973;Bishop et al 1975;De Waal and Calk 1975;Meyer and Boctor 1975;Mitchell and Keays 1981;Lorand and Conquéré 1983; Dromgoole and Pasteris 1987; Fleet and Stone 1990; Szabó and Bodnar 1995), disaggregated clinopyroxene, garnet and diamonds preserved as megacrysts (Figs. 1 and 4; e.g., Peterson and Francis 1977;Gurney et al 1984;Andersen et al 1987; Fleet and Stone 1990;Rudnick et al 1993b; Deines and Harris 1995;Bulanova et al 1996); and tectonically exposed ultramafic sequences derived from the upper, mostly oceanic, mantle ( Fig.…”

Section: Base-metal Sulfide Occurrence Major Element Geochemistry Anmentioning

confidence: 99%

Mantle Sulfides and their Role in Re–Os and Pb Isotope Geochronology

Harvey

Warren

Shirey

2015

Reviews in Mineralogy and Geochemistry

View full text Add to dashboard Cite

ANALYTICAL METHODS AND PRACTICAL ASPECTS OF SAMPLE PREPARATION Over the last 15 years or so, two main methods have been developed for the analysis of Re-Os isotopes in BMS grains; (i) in situ laser ablation multi-collector inductively coupled plasma mass spectrometry (LA MC ICPMS) and (ii) sulfide extraction, chemical purification, and thermal ionization mass spectrometry (TIMS). Lead isotopes have also been measured using the TIMS technique, as well as by in situ secondary ion mass spectrometry (SIMS). There are distinct advantages and disadvantages associated with each analytical method, particularly with respect to sample preparation and interpretation of the information obtained. Early work on Pb, Re, Os, and other PGE concentrations in BMS grains was performed by in situ proton microprobe analysis coupled with a MC ICPMS (Bulanova et al. 1996; Guo et al. 1999). Due to limited availability and because detection limits were higher and standard reproducibility for this method was less precise, in situ determination of Re and PGE

show abstract

“…There are a number of papers [2,3,7,8,10,14] on these sulfides in kimberlites, in most of which the main attention is given to mineralogicai aspects of the sulfides in individual kimberlite bodies. The sulfide assemblages in ultramafites and eclogites have been classified from measure ments on sulfide inclusions in diamonds [8].…”

Section: Xenolith Sulfidesmentioning

confidence: 99%