Stable isotopes and Mg/Ca ratios of Globorotalia truncatulinoides from sediment core M78/1_235-1@en

Stable carbon (δ13C) and oxygen isotope (δ18O) and Mg/Ca-measurements were performed on the planktonic subsurface-dwelling foraminiferal species Globorotalia truncatulinoides. The foraminiferal specimens were selected from piston core M78/1-235-1, which was recovered from Tobago Basin (11°36.53'N 60°57.86'W) from 852 m water depth during R/V Meteor Cruise 78/1. Sampling and analytical studies were carried out from 630 to 800 cm core depth at 1-2 cm spatial resolution. This dataset extends the existing subsurface proxy records (Reißig et al., 2019; doi:10.1594/PANGAEA.897083) further back in time, now focusing on the time period of the latest fully developed D/O events (~30-37 ka BP). The isotope analyses were performed in 2019 on a Thermo Scientific MAT 253 mass spectrometer with an automated Kiel IV Carbonate Preparation Device. Trace metal analyses were performed on a VARIAN 720-ES Axial ICP-OES, a simultaneous, axial-viewing Inductively Coupled Plasma - Optical Emission Spectrometer coupled to a VARIAN SPS3 sample preparation system. The proxy data provide information on the Tobago Basin subsurface hydrography in relation to Western Boundary Current and North Atlantic Subtropical Gyre interdynamics.

本研究针对栖息于次表层水体的浮游有孔虫物种截圆辐球房虫（Globorotalia truncatulinoides），开展了稳定碳同位素（δ¹³C）、氧同位素（δ¹⁸O）及Mg/Ca比值测定。所用有孔虫标本取自活塞岩芯M78/1-235-1，该岩芯由‘流星号’（R/V Meteor）科考船第78/1航次于多巴哥盆地（11°36.53'N 60°57.86'W）水深852米处采获。采样与分析工作覆盖岩芯深度630~800 cm段，空间分辨率为1~2 cm。本数据集将已有的次表层代用指标记录（Reißig等，2019；doi:10.1594/PANGAEA.897083）的时间跨度进一步向后延伸，当前研究聚焦于最新一期完全发育的D/O事件时段（约30~37 ka BP）。同位素分析工作于2019年在赛默飞世尔科技（Thermo Scientific）MAT 253型质谱仪及配套的基耶尔（Kiel）IV型自动碳酸盐制样装置上完成。痕量金属分析则依托瓦里安（VARIAN）720-ES Axial型同步轴向观测电感耦合等离子体发射光谱仪（ICP-OES）完成，该设备配套瓦里安SPS3型样品制备系统。本代用指标数据可用于揭示多巴哥盆地次表层水体水文状况，及其与西边界流和北大西洋副热带环流之间的相互动力学关系。