Birth of a volcanic margin off Argentina, South Atlantic

摘要: [1] Based on a dense grid of multichannel reflection seismic lines we study the evolution volcanic rifted margin segment off Argentina. The under is located between 44°S and 41°S. We describe in detail facies extrusive basaltic complexes across margin. These include single multiple Inner Seaward Dipping Reflectors (SDRs) with varying architecture along margin, Outer Highs, SDR wedges. A detailed interpretation transitional zone wedges presented. Multiple SDRs are concentrated at southern part segment, while north only one steeply dipping wedge present. dip changes propose subsidence by loading as main cause. becomes narrower toward north. By correlating magnetic data conclude that emplacement 30–100 km wide occurred episodically. an injection center which migrated seaward direction proceeding extension origin for SDRs. scissor-like opening resulted different amounts stretching along-strike likely cause distribution complexes. rates within contribute to decreasing volumes melts generated northward this rift segment.