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doi:10.2204/iodp.proc.320321.216.2014

Introduction

One primary objective of the Integrated Ocean Drilling Program (IODP) Pacific Equatorial Age Transect (PEAT) project is to produce continuous records tracking the effects of climate change in the eastern equatorial Pacific with enough detail to resolve orbitally forced climate cycles. A significant part of climate change is recorded by variability in the chemical composition of sediment, but this information is typically difficult to extract at a reasonable cost (see the “Methods” chapter [Expedition 320/321 Scientists, 2010a]).

X-ray fluorescence (XRF) scanning is an economical and nondestructive way to extract chemical data from split cores. XRF scanning is an X-ray optical technique that can measure the majority of the major elements and some minor elements in ~20–30 s per measurement. The vertical spacing at which data were collected for this project is similar to that at which physical properties were gathered on board the ship. The chemical measurements collected from XRF scanning can supplement physical properties measurements to study cyclostratigraphy. If calibrated, XRF scan data can be used to understand the long-term evolution of biogeochemical cycles.

In this data report, we present the results of XRF scanning on the spliced sedimentary sections from Sites U1335–U1337 and describe a basic technique, following Lyle et al. (2012), used to normalize the data for further geochemical study. Both the raw and normalized data along the splices are presented in Tables T1, T2, and T3. We report depth in meters composite depth (mcd) using core composite depth below seafloor (CCSF-A) methodology (see the “Methods” chapter [Expedition 320/321 Scientists, 2010a]). Data at this sampling resolution collected from multiple cores along the transect, along with previously published data from Site U1338 (Lyle et al., 2012; Lyle and Backman, 2013), allow the study of geochemical cycles for long periods of time and across great distances in the eastern equatorial Pacific. Such data can be used to study how biogeochemical changes in the equatorial Pacific are related to long-term changes in global climate.

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