georefid:2000-063784georefid:2000-063779SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.163.107.19991999-01-01publicationgeorefid:2000-063784doi:10.2973/odp.proc.sr.163.107.1999Buecker, Christian J.Joint Geoscientific Research of the State Geological Surveys, Hanover, Federal Republic of GermanyauthorCashman, Katharine V.Oregon State University, United StatesauthorPlanke, SverreOcean Drilling Program, United StatesauthorTexas A & M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentHardcopyIn: Larsen, Hans-Christian, Duncan, Robert A., Allan, James F., Aita, Yoshiaki, Arndt, Nicholas T., Buecker, Christian J., Cambray, Herve, Cashman, Katharine V., Cerney, Brian P., Clift, Peter D., Fitton, J. Godfrey, Le Gall, Bernard, Hooper, Peter R., Hurst, Stephen D., Krissek, Lawrence A., Kudless, Kristen E., Larsen, Lotte Melchior, Lesher, Charles E., Nakasa, Yukari, Niu, Yaoling, Philipp, Harald, Planke, Sverre, Rehacek, Jakub, Saunders, Andrew D., Teagle, Damon A. H., Tegner, Christian, Scroggs, John (editor), Proceedings of the Ocean Drilling Program; scientific results, Southeast Greenland margin; covering Leg 163 of the cruises of the drilling vessel JOIDES Resolution, Reykjavik, Iceland, to Halifax, Nova Scotia, sites 988-990, 3 September-7 October 199516341-49The overall good core recovery in the basaltic sequence and the dense recording of physical and magnetic properties in Hole 990A are well suited to investigate the lava pile in detail, although no wireline measurements could be achieved during the entire Leg 163. The goal of the investigation is to show the different lava flow types with their physical and magnetic properties, based on reliable measurements of density and susceptibility with a sampling interval of 5 cm, and velocity and magnetic intensity with a sampling interval of 10 cm. The top of the volcanic sequence at Site 990 is deeply weathered and oxidized, and all of the lava flow units have oxidized flow tops. In combination with the recovery of soil horizons, this shows that the eruption and emplacement of the lava flows occurred under subaerial conditions. This subaerial emplacement is also indicated by the physical properties with characteristic low density and velocity values at the flow tops, which is a function of the high degree of subaerial flow-top alteration. The lava pile was divided into aa, pahoehoe, and a transitional form as a result of optical core observations as well as by groundmass crystal texture measurements. Highest density and velocity values are found in the aa flows; in particular the velocities of the pahoehoe flows are smaller than in the aa flows. In general, the pahoehoe flows show the highest magnetic intensities, whereas the magnetic intensities for the aa flows are 3.5 times smaller. The magnetic susceptibility shows an opposite trend.completedIgneous and metamorphic petrologyaa lavaArctic regionAtlantic Oceanbasaltscontinental margincoresdensityEast GreenlandGreenlandigneous rockslavaLeg 163magnetic intensitymagnetic propertiesmagnetic susceptibilitymineral compositionNorth AtlanticOcean Drilling Programocean floorsODP Site 990pahoehoepaleomagnetismphysical propertiesSouth Greenlandtexturesvariationsvolcanic rocksurn:org.iodp:exp:163urnlargerWorkCitationcampaignurn:org.iodp:exp:163:site:990urnlargerWorkCitationstudyurn:org.iodp:exp:163urnlargerWorkCitationcampaignEnglishgeoscientificInformation-39.4648-39.464863.282263.2822Data report