Planktic foraminiferal stable isotopes, Mg/Ca, local seawater d18O and temperature differences of sediment core NGHP-01-01A@en

This dataset contains planktic foraminifera Trilobatus sacculifer and Dentoglobigerina venezuelana stable oxygen isotopes, Mg/Ca, local seawater δ18O and ΔT estimates from Site NGHP-01-01A, which was recovered by the drill ship JOIDES Resolution (JR) in the Kerala-Konkan Basin in the Eastern Arabian Sea (EAS; 15º18.366' N, 70º54.192' E; 2663 m water depth) during the Indian National Gas Hydrate Program (NGHP) Expedition 01 in 2006 (28.04.-19.08.2006). The data archived here was generated to reconstruct changes of the upper water column structure, i.e., depth of the mixed later and thermocline at Site NGHP-01-01A in the EAS during the middle Miocene in order to study changes in the summer South Asian Monsoon (SAM). The isotopic composition of the planktic foraminifera samples was analysed at the MARUM, University of Bremen, Germany, using a Finnigan MAT 251 mass spectrometer equipped with an automatic line for carbonate preparation (type \"Kiel III\"). Planktic foraminiferal trace element concentrations were measured using an Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES; Agilent 5110 VDV) at the Center of Major Equipment and Technology (COMET) of the State Key Laboratory of Marine Environmental Science (MEL), Xiamen University. Planktic foraminiferal Mg/Ca ratios were converted to temperature using the the multiple species planktic foraminifera calibration of Anand et al. (2003; doi:10.1029/2002PA000846). To account for past seawater Mg/Ca changes, the D. venezuelana and T. sacculifer Mg/Ca estimates were adjusted for changes in seawater Mg/Ca by modifying the Mg/Ca-temperature calibrations of Anand et al. (2003; doi:10.1029/2002PA000846), following Lear et al. (2015; https://doi.org/10.1002/2015PA002833. Seawater δ18O (δ18Osw) was calculated using the unadjusted and adjusted temperature Mg/Ca-temperature estimates in order to account for past seawater Mg/Ca changes by removing the temperature-driven component of the planktic foraminifera δ18O record. The δ18O-temperature relationship of (Bemis et al., 1998; https://doi.org/10.1029/98PA00070) was used to calculate the δ18Osw estimates. A local record of changes in δ18Osw was derived by subtracting an estimate of middle Miocene ice-volume changes from the δ18Osw record. […]本数据集涵盖取自NGHP-01-01A站位的浮游有孔虫（planktic foraminifera）*Trilobatus sacculifer*与*Dentoglobigerina venezuelana*的稳定氧同位素数据、Mg/Ca比值数据、局地海水δ¹⁸O数据以及ΔT估算结果。该站位由“乔迪斯·决心号”（JOIDES Resolution, JR）钻探船于2006年（2006年4月28日—8月19日）执行的印度国家天然气水合物计划（Indian National Gas Hydrate Program, NGHP）第01航次，在东阿拉伯海（Eastern Arabian Sea, EAS）喀拉拉-康坎盆地（15°18.366′N，70°54.192′E，水深2663米）采集获得。 本数据集归档的实验数据旨在重建中中新世时期东阿拉伯海NGHP-01-01A站位的上层水柱结构变化，即混合层与温跃层深度变化，以探究夏季南亚季风（Summer South Asian Monsoon, SAM）的演化历程。 浮游有孔虫样品的同位素组成在德国不来梅大学MARUM海洋环境科学中心完成分析，测试使用配备碳酸盐自动前处理系统（型号"Kiel III"）的Finnigan MAT 251型质谱仪。 浮游有孔虫的微量元素浓度由厦门大学海洋环境科学国家重点实验室大型仪器与技术中心（Center of Major Equipment and Technology, COMET）采用电感耦合等离子体光发射分光光度计（Inductively Coupled Plasma Optical Emission Spectrophotometer, ICP-OES；安捷伦5110 VDV型）完成测定。 浮游有孔虫的Mg/Ca比值通过Anand等人（2003年；DOI: 10.1029/2002PA000846）建立的多属种浮游有孔虫校准公式转换为海水温度。 为校正古海水Mg/Ca比值变化的影响，本研究参考Lear等人（2015年；DOI: https://doi.org/10.1002/2015PA002833）的方法，通过修正Anand等人（2003年；DOI: 10.1029/2002PA000846）的Mg/Ca-温度校准公式，对*D. venezuelana*与*T. sacculifer*的Mg/Ca估算结果进行了海水Mg/Ca变化校正。 通过去除浮游有孔虫氧同位素记录中的温度驱动组分，结合未校正与校正后的Mg/Ca-温度估算结果，本研究计算得到海水δ¹⁸O（δ¹⁸Osw）数据，以抵消古海水Mg/Ca比值变化的影响。 本研究采用Bemis等人（1998年；DOI: https://doi.org/10.1029/98PA00070）建立的δ¹⁸O-温度关系计算δ¹⁸Osw数值。 通过从δ¹⁸Osw记录中扣除中中新世冰量变化的估算值，本研究得到局地δ¹⁸Osw变化记录。[…]