Results 141 to 150 of about 858 (191)
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186Os–187Os Systematics of Hawaiian Picrites
Earth and Planetary Science Letters, 1999Abstract Primitive Hawaiian picrites have 187Os/188Os as high as ∼0.145 and are more radiogenic than the depleted upper mantle, reflecting a time-integrated suprachondritic Re/Os ratio. The high Re/Os may be explained either by an ancient recycled crustal component or an evolved outer core component in the Hawaiian plume.
Marc D. Norman +2 more
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Picrites as Parental Magma of MORB-Type Tholeiites
Nature, 1982Recent experimental work on peridotites and basalts1–3 and a reappraisal of ophiolite complexes4 supports the concept that basalts are derived from picritic parents5–7. The occurrence of a density minimum in the liquid line of descent8–10 explains why mid-ocean ridge tholeiites fall in a restricted compositional range, and parental picrites can only be
P Maaskant
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Lithos, 2019 Like many continental flood basalt (CFB) provinces in the world, the source mantle compositions (peridotites or pyroxenites) of the Emeishan CFB province in SW China are still debated. We have used the combination of olivine O isotopes determined in situ
Chusi Li, Hong Zhong, Zhong-Jie Bai
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Geochimica Et Cosmochimica ActaInternational audience Hf-182 W and 146 Sm-142 Nd short-lived radiogenic isotope systems, 176 Lu-176 Hf, 147 Sm-143 Nd, 190 Pt-186 Os, and 187 Re-187 Os long-lived radiogenic isotope systems, mantle evolution, highly siderophile elements, picrites and ...
Jan L. Hellmann +2 more
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Transactions of the Royal Society of Edinburgh, 1962
SynopsisA Small picrite sill of critical significance is examined in detail, from top to bottom, with particular reference to the distribution and crystallization of the olivine. Statistical evaluation of the sizes of olivine crystals establishes a gradation from large phenocrysts to small groundmass crystals.
Wyllie, P. J., Drever, H. I.
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SynopsisA Small picrite sill of critical significance is examined in detail, from top to bottom, with particular reference to the distribution and crystallization of the olivine. Statistical evaluation of the sizes of olivine crystals establishes a gradation from large phenocrysts to small groundmass crystals.
Wyllie, P. J., Drever, H. I.
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The Fe and Zn Isotope Composition of Deep Mantle Source Regions: Insights From Baffin Island Picrites [PDF]
Geochimica Et Cosmochimica Acta, 2018 Young (61 Ma) unaltered picrites from Baffin Island, northeast Canada, possess some of the highest 3He/4He (up to 50 Ra) seen on Earth, and provide a unique opportunity to study primordial mantle that has escaped subsequent chemical modification.
Marie-Laure Pons +2 more
exaly +4 more sources
The mantle origins of Karoo picrites
Earth and Planetary Science Letters, 1991Karoo picrites are divided into a volumetrically dominant high Ti-Zr (HTZ) group and a less abundant low Ti-Zr (LTZ) group. Distinguished in this way, it is then possible to use the comparison of major element compositions with those of experimentally determined partial melts of mantle peridotites to constrain the depth of segregation for each magma ...
R.J. Sweeney +3 more
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Nature, 1991
ESTIMATES of the MgO content of primary Hawaiian tholeiitic melts range from 8wt% to as high as 25wt%. In general, these estimates are derived from analysis of the whole-rock composition of lavas, coupled with the compositions of the most magnesian olivine phenocrysts observed. But the best estimate of magma composition comes from volcanic glass, as it
Clague, David A. +2 more
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ESTIMATES of the MgO content of primary Hawaiian tholeiitic melts range from 8wt% to as high as 25wt%. In general, these estimates are derived from analysis of the whole-rock composition of lavas, coupled with the compositions of the most magnesian olivine phenocrysts observed. But the best estimate of magma composition comes from volcanic glass, as it
Clague, David A. +2 more
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Modelling the ascent of picritic lunar magmas
2021<p>Quantifying the volatile content of the lunar interior is valuable for understanding the formation, thermal evolution, and magmatic evolution of the Earth and Moon. Petrological modelling and geochemical measurements have been used to study the volatile composition of the lunar interior.
Marissa Lo +4 more
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Stabiliser degradation in picrite propellants
Journal of Applied Chemistry, 1960AbstractPicrite propellants (N, NQ, SPCG) were artificially aged at 65° and the rate and manner of decomposition were followed by separation and analyses of the products derived from the stabiliser due to its combination with nitrogen oxides. An SC formulation which does not contain picrite was treated in a similar manner.The total amount of ...
Paul E. Gagnon +3 more
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