Eocene clastic rocks at Site 1276 are truly grainstones or calcarenites with minor terrigenous components. They likely represent a continuum of mixing between two sources, one siliciclastic the other calcareous. As outlined above, the proportions and types of silicilastic grains in these sediments suggest a similar siliciclastic source to that of the underlying Cretaceous section. Additional evidence comes from the distribution of mica ages, which are also similar to Cretaceous samples (Wilson and Hiscott, this volume). The calcareous source was likely a carbonate shelf environment in that anomalous, large Eocene benthic foraminifers concentrated in Cores 210-1276A-7R through 15R are generally associated with warmer shallow-water reef environments (see discussion in Georgescu et al., submitted [N2]). Eocene grainstones are also present on the Iberian conjugate margin, but unlike the Site 1276 Eocene grainstones, the Site 398 samples contain mostly planktonic foraminifer bioclasts associated with recycled(?) carbonate lithic clasts that are present throughout the section (Table T1). The carbonate system on Galicia Bank likely extended to the Iberian shelf, in that Eocene sandstones recovered to the south (Fig. F4) during Legs 149 (Marsaglia et al., 1996) and 173 (Wallrabe-Adams, 2001) are also calcareous. Eocene foreland basin clastic rocks of the Pyrenees are also similarly calcareous (Fontana et al., 1989), suggesting that this was a regional phenomenon. Because Fontana et al. (1989) worked with coarser arenites and microrudites, they were able to differentiate coeval intrabasinal intraclasts from detrital carbonate clasts supplied by upthrusted Cretaceous carbonate units. In contrast, bioclastic debris is the main indicator of recycling within the fine to very fine sandstones at Site 1276 (Georgescu et al., submitted [N2]). Fontana et al. (1989) report large quantities of intrabasinal bioclastic debris such as benthic and planktonic foraminifers, bryozoans, echinoderms, algal grains, and shell fragments. Despite the active tectonic setting of the Pyrenees during the Eocene, Fontana et al. (1989) called on eustacy to explain the carbonate-rich sandstones, through intrabasinal carbonate input during sea level rise and erosion of highstand carbonate complexes during sea level fall. Similar eustatic-driven processes may have been acting along the Newfoundland margin during the Eocene, but in a passive margin rather than a foreland basin setting.