Zobrazeno 1 - 10
of 17
pro vyhledávání: '"David Ulfbeck"'
Publikováno v:
Geochimica et Cosmochimica Acta. 72:5146-5163
We have reinvestigated the Mn–Cr systematics in a number of primitive meteorites, differentiated planetesimals and terrestrial planets in order to address the chronology of the early stages of protoplanetary disk evolution and planetary formation.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d717a7ae0a16f18c6bfd55b377c10631
https://doi.org/10.1016/j.gca.2008.03.023
https://doi.org/10.1016/j.gca.2008.03.023
Autor:
James N. Connelly, Martin Bizzarro, Kristine Thrane, David Ulfbeck, Bradley S. Meyer, Anne Trinquier
Publikováno v:
Science. 316:1178-1181
High-precision 60 Fe- 60 Ni isotope data show that most meteorites originating from differentiated planetesimals that accreted within 1 million years of the solar system's formation have 60 Ni/ 58 Ni ratios that are ∼25 parts per million lower than
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::40572a97585d175f66753ba8d34cdb57
https://doi.org/10.1126/science.1141040
https://doi.org/10.1126/science.1141040
Autor:
Nathalie Grassineau, David Ulfbeck, Maxim Portnyagin, Svend Duggen, Dieter Garbe-Schönberg, Kaj Hoernle, Joel A. Baker
Publikováno v:
Geochimica et Cosmochimica Acta. 71:452-480
The shift of lava geochemistry between volcanic front to rear-arc volcanoes in active subduction zones is a widespread phenomenon. It is somehow linked to an increase of the slab surface depth of the subducting oceanic lithosphere and increasing thic
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8554e4db2df261013476a88f30942486
https://doi.org/10.1016/j.gca.2006.09.018
https://doi.org/10.1016/j.gca.2006.09.018
Publikováno v:
Chemical Geology. 233:126-136
A two-stage method is presented to separate Lu and Hf from silicate rock and mineral samples digested by either flux melting or HF–HNO3 dissolution using TODGA resin from Eichrom Industries. A first-stage chemistry employs a 2-ml cation exchange co
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cebe5e2d0524f9a42959549e442afb51
https://doi.org/10.1016/j.chemgeo.2006.02.020
https://doi.org/10.1016/j.chemgeo.2006.02.020
Publikováno v:
Geostandards and Geoanalytical Research. 27:133-145
A new digestion procedure and chemical separation technique has been developed for measurement of Lu/Hf and Hf isotope ratios that does not require high-pressure bombs or use of HF or HClO4 acids. Samples are digested in dilute HCl or HNO3 after flux
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f5c0ae0db1a904725e65d0acbcada8d5
https://doi.org/10.1111/j.1751-908x.2003.tb00641.x
https://doi.org/10.1111/j.1751-908x.2003.tb00641.x
Publikováno v:
Geochimica et Cosmochimica Acta. 66:3635-3646
A method has been developed for the rapid chemical separation and highly reproducible analysis of the rare earth elements (REE) by isotope dilution analysis by means of a multiple collector inductively coupled plasma mass spectrometer (MC-ICP-MS). Th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3cd3ef0a60821faed5c8a28851353139
https://doi.org/10.1016/s0016-7037(02)00921-3
https://doi.org/10.1016/s0016-7037(02)00921-3
Publikováno v:
Geochimica et Cosmochimica Acta. 66:467-486
Despite superimposed metamorphic overprinting and metasomatic alterations, primary volcanic features remain preserved in low-strain domains of mafic volcanic sequences in the western Isua supracrustal belt (ISB, West Greenland). These basaltic succes
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::90fc25c31e46806f698e036f41b08ba9
https://doi.org/10.1016/s0016-7037(01)00781-5
https://doi.org/10.1016/s0016-7037(01)00781-5
Autor:
Alexander N. Krot, Martin Bizzarro, Anne Trinquier, David Ulfbeck, Christopher D. Coath, Tim Elliott
Publikováno v:
Science. 324:374-376
Stable-isotope variations exist among inner solar system solids, planets, and asteroids, but their importance is not understood. We report correlated, mass-independent variations of titanium-46 and titanium-50 in bulk analyses of these materials. Bec
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e2cc5423bd9747e9bd3112bef44dc23
https://doi.org/10.1126/science.1168221
https://doi.org/10.1126/science.1168221
Publikováno v:
Canadian Journal of Earth Sciences. 35:802-819
The Palaeoproterozoic Nagssugtoqidian Orogen in West Greenland represents a mid- to deep-crustal section through a collisional orogen with a complex intrusive, tectonic, and metamorphic history. In the northeastern central part of the orogen, in the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::646114d559ec33d492a8772775eb2617
https://doi.org/10.1139/e98-030
https://doi.org/10.1139/e98-030
Publikováno v:
Nature. 421:931-933
The 176Lu to 176Hf decay series has been widely used to understand the nature of Earth's early crust–mantle system1,2,3,4,5,6. The interpretation, however, of Lu–Hf isotope data requires accurate knowledge of the radioactive decay constant of 176
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8cba01c4dffd86ee3093b7ae8d718e4a
https://doi.org/10.1038/nature01421
https://doi.org/10.1038/nature01421