INTRODUCTION

The 1.2- to 0.6-Ma interval of Sites 1014 and 1020 was sampled at 25- and 30-cm intervals, respectively, from their respective composite spliced sections. This interval was selected to assess changes in deep and intermediate Pacific Ocean circulation associated with the onset of large 100-k.y. glacial-interglacial cycles near ~0.8-1.0 Ma. Site 1014 was drilled in the Tanner Basin (1176 m) and was selected in this study to monitor past changes in the ¹³C composition of Pacific intermediate waters ventilating the California Borderland basins. Site 1020 from the Gorda Ridge (3040 m) was selected for this study to monitor past variations in the ¹³C composition of northeast Pacific deep waters. Average sedimentation rates for the Brunhes Chron intervals of Sites 1014 and 1020 were 8 and 11 cm/k.y., respectively (using composite depths). These sampling densities were selected to produce a mean temporal resolution of 2.5-3.0 k.y. Samples were taken from the ~0.6- to ~1.2-Ma intervals of the shipboard composite splice for Sites 1014 (~35-95 meters composite depth [mcd]) and 1020 (~65.0-119.0 mcd).