georefid:2007-088104georefid:2007-088081SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.149.216.1996<gco:CharacterString>Geochemistry of serpentinized mantle peridotite from Site 897 in the Iberia abyssal plain</gco:CharacterString>1996-01-01publicationgeorefid:2007-088104doi:10.2973/odp.proc.sr.149.216.1996Seifert, Karl E.Iowa State University, Department of Geological and Atmospheric Sciences, Ames, IA, United StatesauthorBrunotte, DaleRice University, United StatesauthorTexas A&M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentDigitalIn: Whitmarsh, Robert B., Sawyer, Dale S., Klaus, Adam, Beslier, Marie-Odile, Collins, Eric S., Comas, Maria Carmen, Cornen, Guy, de Kaenel, Eric, Pinheiro, Luis de Menezes, Gervais, Elisabeth, Gibson, Ian L., Harry, Dennis L., Hobart, Michael A., Kanamatsu, Toshiya, Krawcyzk, Charlotte M., Liu, Li, Lofts, Jeremy C., Marsaglia, Kathleen M., Meyers, Philip A., Milkert, Doris, Milliken, Kitty L., Morgan, Julia K., Ramirez, Pedro, Seifert, Karl E., Shaw, Timothy J., Wilson, Chris, Yin, Chuan, Zhao, Xixi, Proceedings of the Ocean Drilling Program; scientific results, Iberia abyssal plain; covering Leg 149 of the cruises of the Drilling Vessel JOIDES Resolution; Balboa Harbor, Panama, to Lisbon, Portugal; sites 897-901, 10 March-25 May 1993149413-424Serpentinized mantle peridotites from Site 897 are highly variable in composition and mineralogy, ranging from lherzolites to harzburgites and, more infrequently, to dunites. Lherzolites are enriched in Al (sub 2) O (sub 3) , TiO (sub 2) , CaO, Cr (sub 2) O (sub 3) and rare-earth elements relative to harzburgites and dunites, which are enriched in MgO and NiO. Texturally some of the lherzolites are characterized by mylonitic bands of fine-grained plagioclase, clinopyroxene, orthopyroxene, and olivine between larger crystals of olivine, orthopyroxene, clinopyroxene, plagioclase, and chrome spinel. These textural characteristics suggest the lherzolites have been enriched by intrusion of basaltic magma. Moreover, some of the lherzolites have flat rare-earth-element patterns near chondritic abundance, and regarded as typical of primitive mantle, whereas others have rare-earth-element patterns similar to normal mid-ocean ridge basalt, suggesting metasomatic enrichment by the addition of a normal mid-ocean ridge basaltic magma. The vertical and lateral heterogeneity of mantle peridotites at Site 897 shows that the mantle can be locally heterogeneous and that modeling of the mantle as a few layers of relatively homogeneous material represents a vast oversimplification that has no significance at the local level.completedIgneous and metamorphic petrologyAtlantic Oceanchemical compositionEuropeGalicia Margingeochemistryhigh temperatureIberian abyssal plainIberian Peninsulaigneous rocksLeg 149lherzolitemantlemetamorphismmetasomatismmineral compositionNorth AtlanticNortheast AtlanticOcean Drilling ProgramODP Site 897P-T conditionsperidotitesplutonic rocksserpentinizationSouthern Europetectonicstemperatureultramaficsurn:org.iodp:exp:149urnlargerWorkCitationcampaignurn:org.iodp:exp:149:site:897urnlargerWorkCitationstudyurn:org.iodp:exp:149urnlargerWorkCitationcampaignEnglishgeoscientificInformation-12.2847-12.284740.501940.5019application/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www-odp.tamu.edu/publications/149_SR/VOLUME/CHAPTERS/SR149_23.PDFdownload