We present new stable isotope and dissolution records for a composite "Carnegie Platform" (CP) sediment record composed of KNR195-5 cores CDH-36 and MC-34A (3° 35.85' S, 83° 57.79' W, 3225 m). Renewed interest in this previously studied Eastern Equatorial Pacific paleoceanographic site prompted a re-coring using the recently developed CDH giant piston coring system. Giant piston core CDH-36, with a core length of 42.61 m, nearly triples the length of previous cores taken at this site. CDH-36 is combined with multicore MC-34A (0.36 m length) to obtain a continuous sediment record through the Holocene into the present day (0 ka). A new age model using radiocarbon dates from both cores and an alignment of the CDH-36 delta 18O record with the LR04 benthic stack (Lisiecki and Raymo, 2005) demonstrates that the CP record extends to 720 ka, to the end of MIS 18.

Comparisons of the CP stable isotope records with regional Pacific records show consistencies in timing of glacial and interglacial episodes. We also evaluate the %CF ([coarse fraction/bulk dry sample] * 100) record of the CP core as well as the %fragmentation (100*[( frag/8)/(( frag/8)+( whole))]) (Le and Shackleton, 1992) at certain intervals in order to assess dissolution within the CP record. We find that the continuous %CF record primarily records Pleistocene dissolution cycles. These cycles are consistent with previous studies of tropical Pacific cores, such as those of Le and Shackleton (1992) and Lalicata and Lea (2011). There are a number of hypotheses for ocean or basin-wide calcium carbonate dissolution cycles, including changes in terrestrial carbon input to the oceans and in water mass ventilation (Shackleton, 1977; Toggweiler et al., 2006; Sexton and Barker, 2012).

Despite the hypothesized Pacific-wide dissolution cycles, there are still clear differences between the %CF records of tropical Pacific cores. These differences likely reflect the impact of secondary processes such as changes in terrigenous input, winnowing away of fine-grained sediments from bathymetrically highs, and core depth relative to the lysocline. Based on comparisons of the newly established CP record with other Pacific records of dissolution, proxy work is needed to address the influence of these secondary processes on the %CF record in order to better quantify the full extent of dissolution and its governing processes.