Sr isotopic ratios of Holocene gypsum and anhydrite salt deposits in Atacama Desert, northern Chile

This file provides 87Sr/86Sr data for calcium sulfate salts of Holocene age in the Atacama Desert of northern Chile, where gypsum and anhydrite surficial accumulations are widespread. The purpose of the Sr isotopic study is to differentiate among sources of the ions in these minerals. Gypsum/anhydrite was selected for sampling that occurs as crystals adhering to surfaces whose other sedimentary materials are likely to have been deposited in the last few hundred years. The age of last transport of that sediment has not been dated, but evidence indicates it to be younger than the time of major climate change (from arid to hyperarid) at the close of the Pleistocene, hence Holocene. Samples of 28 Holocene surface salt accumulations for locations between 200-2950 meters above sea level and between approximately 19 degrees 30 minutes S latitude and approximately 21 degrees 30 minutes S latitude quantify a variation in 87Sr/86Sr as a function of site altitude.

本文件提供了智利北部阿塔卡马沙漠全新世年龄的硫酸钙盐中87Sr/86Sr数据。在该地区，石膏和硬石膏的表生堆积广泛分布。本项87Sr同位素研究的目的是区分这些矿物中离子的来源。石膏/硬石膏被选为采样对象，这些样品以晶体形式附着在表面，而其他可能的沉积材料可能是近几百年来沉积的。该沉积物最后搬运的年龄尚未确定，但证据表明其年代早于更新世末期（从干旱变为极端干旱）的重大气候变化，因此属于全新世。海拔在200-2950米之间，纬度约在19度30分南至21度30分南之间的28个全新世地表盐堆积样品，量化了87Sr/86Sr随海拔高度的变化。