Seismic characteristics of basaltic extrusive and intrusive rocks

Transient, voluminous basaltic volcanism is frequently associated with continental breakup, forming so-called volcanic rifted continental margins. Until recently, most rifted margins were considered nonvolcanic; however, the improvement in seismic imaging techniques has shown that breakup volcanism is a common phenomenon. At the November 1997 Volcanic Margin Workshop in Potsdam, it was shown that at least 70% of the Atlantic margins are volcanic (a number which may apply to the Indian Ocean margins as well).