The Southeast Greenland rifted continental margin (Fig. 1) possesses a thick succession of seaward-dipping lava flows, known from seismic sections as seaward-dipping reflector sequences (SDRS). These volcanics were erupted during breakup of the North Atlantic in the early Tertiary (e.g., Larsen and Saunders, 1998; also reviewed by Saunders et al., 1997). The objective of Leg 163 at the Southeast Greenland margin was to complete a transect across the margin at 63ºN, which had been initiated during Leg 152, and to obtain rock samples for a parallel transect at 66ºN (Duncan, Larsen, Allan, et al., 1996). The drilled cores from Legs 152 and 163 cover a large part of the volcanic stratigraphy, in particular the earlier part of the succession with the important transition from prebreakup continental volcanism to postbreakup oceanic volcanism (Larsen, Saunders, Clift, et al., 1994; Fitton et al., 1995, 1998a, 1998b).

During Leg 163, some of the earliest oceanic volcanic rocks immediately overlying the breakup transition zone were drilled at Site 990. A hole intended to cover the earliest part of the continental succession was also drilled (Site 989). This paper presents the major and trace element composition of the rocks from the 63ºN transect recovered during Leg 163 and places them within the combined succession obtained from Legs 152 and 163. Complementary trace element and isotope data for a subset of samples are presented and discussed by Saunders et al. (Chap. 8, this volume). Also during Leg 163, we drilled a hole on the planned 66ºN transect but recovered only one fresh lava flow. Data for this flow are included in Saunders et al. (Chap. 8, this volume) and are not addressed in this paper.