FN Archimer Export Format PT J TI Thinning of the Goban Spur continental margin and formation of early oceanic crust: Constraints from forward modelling and inversion of marine magnetic anomalies BT AF LOUVEL, Veronique DYMENT, Jerome SIBUET, Jean-Claude AS 1:1;2:2;3:3; FF 1:;2:;3:; C1 INST PHYS GLOBE STRASBOURG, CNRS URA 323, F-67084 STRASBOURG, FRANCE. UNIV BRETAGNE OCCIDENTALE, CNRS URA 1278, F-29285 BREST, FRANCE. IFREMER, CTR BREST, F-29280 PLOUZANE, FRANCE. C2 IPGP, FRANCE UBO, FRANCE IFREMER, FRANCE IN WOS Ifremer jusqu'en 2018 IF 1.544 TC 5 UR https://archimer.ifremer.fr/doc/00337/44777/44601.pdf LA English DT Article DE ;continental margin;Goban Spur;magnetic anomalies;ocean-continent boundary AB The deep seismic reflection profile Western Approaches Margin (WAM) cuts across the Goban Spur continental margin, located southwest of Ireland. This non-volcanic margin is characterized by a few tilted blocks parallel to the margin. A volcanic sill has been emplaced on the westernmost tilted block. The shape of the eastern part of this sill is known from seismic data, but neither seismic nor gravity data allow a precise determination of the extent and shape of the volcanic body at depth. Forward modelling and inversion of magnetic data constrain the shape of this volcanic sill and the location of the ocean-continent transition. The volcanic body thickens towards the ocean, and seems to be in direct contact with the oceanic crust. In the contact zone, the volcanic body and the oceanic magnetic layer display approximately the same thickness. The oceanic magnetic layer is anomalously thick immediately west of the volcanic body, and gradually thins to reach more typical values 40 km further to the west. The volcanic sill would therefore represent the very first formation of oceanic crust, just before or at the continental break-up. The ocean-continent transition is limited to a zone 15 km wide. The continental magnetic layer seems to thin gradually oceanwards, as does the continental crust, but no simple relation is observed between their respective thinnings. PY 1997 PD JAN SO Geophysical Journal International SN 0956-540X PU Oxford Univ Press VL 128 IS 1 UT A1997WC16600013 BP 188 EP 196 DI 10.1111/j.1365-246X.1997.tb04079.x ID 44777 ER EF