Mg/Ca ratios of Neogloboquadrina pachyderma (s) and Globigerina bulloides in Irminger Sea sediment trap time series ...

• Main Authors: Jonkers, Lukas, Jimenez-Amat, Patricia, Mortyn, P Graham, Brummer, Geert-Jan A
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Event label; Sample code/label; DATE/TIME; Date/time end; DEPTH, water; Neogloboquadrina pachyderma, Magnesium/Calcium ratio; Globigerina bulloides, Magnesium/Calcium ratio; Trap, sediment; Inductively coupled plasma - mass spectrometry ICP-MS; Irminger Sea; Neogloboquadrina pachyderma; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.816232; https://doi.pangaea.de/10.1594/PANGAEA.816232

iven the importance of high-latitude areas in the ocean-climate system, there is need for a paleothermometer that is reliable at low temperatures. Here we assess the applicability of the Mg/Ca-temperature proxy in colder waters (5-10 °C) by comparing for the first time the seasonal Mg/Ca and d18O cycles of N. pachyderma (s) and G. bulloides using a sediment trap time-series from the northern North Atlantic. While both species show indistinguishable seasonal d18O patterns that clearly track the near surface temperature cycle, their Mg/Ca are very different. G. bulloides Mg/Ca is high (2.0-3.1 mmol/mol), but varies in concert with the seasonal temperature cycle. The Mg/Ca of N. pachyderma (s), on the other hand, is low (1.1-1.5 mmol/mol) and shows only a very weak seasonal cycle. The d18O patterns indicate that both species calcify in the same depth zone. Consequently, depth habitat differences cannot explain the contrasting Mg/Ca patterns. The elevated Mg/Ca in pristine G. bulloides might be due to the ... : Supplement to: Jonkers, Lukas; Jimenez-Amat, Patricia; Mortyn, P Graham; Brummer, Geert-Jan A (2013): Seasonal Mg/Ca variability of N. pachyderma (s) and G. bulloides: Implications for seawater temperature reconstruction. Earth and Planetary Science Letters, 376, 137-144 ...