Neodymium isotope data of sediment core MD05-2925

This data set reports hydrogenous Nd isotopes from the western tropical Pacific, spanning the last 23,000 years, and explores its use as an indicator of hydroclimatic and weathering changes in this environment. The hydrogenous Nd isotopes were extracted from fish teeth and cleaned with multiple sonication steps using ultrapure water and optima-grade methanol. Cleaned samples were dissolved using a 1:1 mixture of optima-grade Hydrochloric and Nitric acid and dried down. Cleaned fish teeth were re-dissolved in 0.5 ml of 1N HNO3, and rare earth elements were separated using 100 μL shrink-fit Teflon columns, loaded with Eichrom TRUspec resin (100–150 μm mesh) and 1N HNO3 as eluent. Nd was separated from the rare earth elements using calibrated Teflon columns pre-loaded with Eichrom LNspec resin (50-100 μm mesh) and 0.25 N HCl as eluent. The samples were analyzed at Pennsylvania State University (PSU) and the Lamont-Doherty Earth Observatory at Columbia University (LDEO) using a Thermo Scientific Neptune-Plus® multicollector-inductively coupled plasma-mass spectrometer (MC-ICP-MS). Measured 143Nd/144Nd ratios are corrected using 146Nd/144Nd = 0.7219 and an exponential mass fractionation law. All samples are bracketed by JNdi-1, that are concentration matched, that is, the JNdi-1 concentration is adjusted to the sample concentration. The reported 143Nd/144Nd ratios are expressed as εNd values, defined as the deviation of the 143Nd/144Nd ratio in a sample from the average value of a chondritic uniform reservoir (=0.512638) in parts per 104. The typical external reproducibility for a 20 ppb JNdi-1 solution is better than ±0.3 εNd units (2SD). Both internal and external errors are reported here. Parameters:Event Label LatitudeLongitudeElevation (m)Depth (cm)Age (cal kyr BP)Normalized 143Nd/144Nd εNd εNd (Internal error, 2SE) εNd (external error, 2 σ)