0 , in two drift cores (TN057-21 and Ocean Drilling Program Site 1089) are nearly identical during the interval of overlapping analyses, MIS 4-5c. SSTs in a nearby nondrift core (TN057-6) covary with those in core TN057-21 throughout MIS 1-5c. While climatological SSTs overlying TN057-21 and TN057-6 are similar and consistent with reconstructed Holocene SSTs in the nondrift core, surface waters overlying TN057-21 are � 6� C colder than Holocene alkenone SSTs in the drift core. Temperatures remain � 6� C warmer in TN057-21 relative to TN057-6 during the � 100 kyr duration of the records. We hypothesize that alkenone-derived SSTs in TN057-21 are higher than climatological SSTs in the overlying surface water and those in TN057-6 as a result of the winnowing and focusing of sedimentary alkenones produced in warmer waters to the north. Climatological SSTs in the central and northern Cape Basin are 16� -20� C. A � 1.5% offset of fine fraction d18O values relative to planktonic foraminifera in TN057-21 supports this hypothesis. Temporal changes in sediment focusing were evaluated directly using uranium series radioisotopes. While higher sediment focusing factors would be expected to result in higher alkenone-derived SSTs if sediment advection were the primary control on down-core changes in alkenone-derived SSTs, 230Th-derived focusing factors indicate no such correlation exists. We conclude that alkenone paleotemperature reconstructions from southern Cape Basin drifts reliably record regional SST variations in the Cape Basin. INDEX TERMS: 4267 Oceanography: General: Paleoceanography; 1055 Geochemistry: Organic geochemistry; 1040 Geochemistry: Isotopic composition/chemistry; 3022 Marine Geology and Geophysics: Marine sediments—processes and transport; KEYWORDS: alkenones, Cape Basin, thorium