Shatsky Rise is a moderately sized large igneous province that was erupted episodically at a hotspot triple junction intersection between 146 and 133 Ma (Tithonian–Valanginian) at equatorial latitudes. Subsidence of the rise occurred soon after its construction, and Early Cretaceous water depths were probably on the order of 1.0–2.3 km. The sites were thus above the calcite compensation depth throughout the Cretaceous (Bralower, Premoli Silva, Malone, et al., 2002). Shatsky Rise was located close to the equator through the entire Early Cretaceous interval, drifting around 8° from a slightly northerly location between 140 and 120 Ma and maintaining an equatorial position between 120 and 100 Ma (Bralower, Premoli Silva, Malone, et al., 2002; Sager et al., this volume; Robinson et al., 2004).
Site 1207 is located on the northernmost high, Site 1208 on the Central High, and Sites 1212–1214 (the latter is equivalent to Deep Sea Drilling Project [DSDP] Site 306) on the Southern High of Shatsky Rise (Fig. F1). The Northern and Southern Highs are currently separated by 5° of latitude. The Cretaceous sections recovered at all three sites are characterized by ubiquitous and abundant chert that greatly affected core recovery, which was poor throughout (7%–13%) (Bralower, Premoli Silva, Malone, et al., 2002). Nevertheless, every core produced some sediment, usually chert or porcellanite, accompanied by layers or vugs of variably lithified nannofossil-rich carbonate. We were able to generate a continuous calcareous nannoplankton record, but sample spacing is often limited to 9–10 m and the small amount of carbonate sediment available generally prohibited the recovery of foraminifers (Bralower, Premoli Silva, Malone, et al., 2002).
Hole 1208A was terminated after recovery of one Albian core, and Site 1212 recovered only four Albian cores (10 m), but both are included here for completeness.