Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: Results from IODP Site U1309 (Atlantis Massif, 30 degrees N Mid-Atlantic-Ridge) (Articolo in rivista)

Type
Label
  • Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: Results from IODP Site U1309 (Atlantis Massif, 30 degrees N Mid-Atlantic-Ridge) (Articolo in rivista) (literal)
Anno
  • 2009-01-01T00:00:00+01:00 (literal)
Alternative label
  • Godard M. (a), Awaji S. (b), Hansen H.(c), Hellebrand E.(d), Brunelli D.(e,f), Johnson K.(d), Yamasaki T.(g), Maeda J.(g), Abratis M.(h), Christie D.(i), Kato Y.(b), Mariet C.(j), Rosner M. (k,l) (2009)
    Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: Results from IODP Site U1309 (Atlantis Massif, 30 degrees N Mid-Atlantic-Ridge)
    in Earth and planetary science letters
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Godard M. (a), Awaji S. (b), Hansen H.(c), Hellebrand E.(d), Brunelli D.(e,f), Johnson K.(d), Yamasaki T.(g), Maeda J.(g), Abratis M.(h), Christie D.(i), Kato Y.(b), Mariet C.(j), Rosner M. (k,l) (literal)
Pagina inizio
  • 110 (literal)
Pagina fine
  • 122 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#altreInformazioni
  • doi:10.1016/j.epsl.2008.12.034 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 279 (literal)
Rivista
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • (a) Géosciences Montpellier, CNRS, Université Montpellier 2, 34095 Montpellier, France (b) Department of Geosystem Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan (c) University of Bergen, Department of Earth Science, Allegt. 41, 5007 Bergen, Norway (d) University of Hawaii, Dept. of Geology and Geophysics, Honolulu, Hawaii, USA (e) Dipartimento di Scienze della Terra, Università di Modena e Reggio Emilia, 41100 Modena, Italy (f) Institute of Marine Sciences, ISMAR-CNR, Via Gobetti, 101, 40129 Bologna, Italy (g) Division of Natural History Sciences, Hokkaido University, N10 W8, Kita-ku, Sapporo 060-0810, Japan (h) Institute of Geosciences, University of Jena, D-07749 Jena, Germany (i) West Coast & Polar Regions Undersea Research Center, University of Alaska, Fairbanks, AK 99775-7220, USA (j) Laboratoire Pierre Süe CEA — CNRS/UMR 9956 Centre de Saclay, Bât. 637 91191 Gif sur Yvette Cedex, France (k) University of Bremen, Petrology of the Oceanic Crust, PO Box 330440. 28334 Bremen, Germany (l) GFZ German Research Centre for Geosciences, Inorganic and Isotope Geochemistry, Telegrafenberg, 14473 Potsdam, Germany (literal)
Titolo
  • Geochemistry of a long in-situ section of intrusive slow-spread oceanic lithosphere: Results from IODP Site U1309 (Atlantis Massif, 30 degrees N Mid-Atlantic-Ridge) (literal)
Abstract
  • IODP Site U1309 was drilled at Atlantis Massif, an oceanic core complex, at 30°N on the Mid-Atlantic Ridge (MAR). We present the results of a bulk rock geochemical study (major and trace elements) carried out on 228 samples representative of the different lithologies sampled at this location. Over 96% of Hole U1309D is made up of gabbroic rocks. Diabases and basalts cross-cut the upper part of the section; they have depleted MORB compositions similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic and geochemical evidence of extensive melt–rock interactions. Gabbroic rocks comprise: olivine-rich troctolites (> 70% modal olivine) and troctolites having high Mg# (82–89), high Ni (up to 2300 ppm) and depleted trace element compositions (Yb 0.06–0.8 ppm); olivine gabbros and gabbros (including gabbronorites) with Mg# of 60–86 and low trace element contents (Yb 0.125–2.5 ppm); and oxide gabbros and leucocratic dykes with low Mg# (< 50), low Ni (not, vert, similar 65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros are amongst the most primitive and depleted oceanic gabbroic rocks. The main geochemical characteristics of Site U1309 gabbroic rocks are consistent with a formation as a cumulate sequence after a common parental MORB melt, although (lack of systematic) downhole variations indicate that the gabbroic series were built by multiple magma injections. In detail, textural and geochemical variations in olivine-rich troctolites and gabbronorites suggest chemical interaction (assimilation?) between the parental melt and the intruded lithosphere. Site U1309 gabbroic rocks do not represent the complementary magmatic product of 30°N volcanics, although they sample the same mantle source. The bulk trace element composition of Site U1309 gabbroic rocks is similar to primitive MORB melt compositions; this implies that there was no large scale removal of melts from this gabbro section. The occurrence of such a large magmatic sequence implies that a high magmatic activity is associated with the formation of Atlantis Massif. Our results suggest that almost all melts feeding this magmatic system stays trapped into the intruded lithosphere. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Prodotto
Autore CNR di
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it