Schulz, MichaelJohnstone, HeatherHeatherJohnstone2020-03-092020-03-092010-11-15https://media.suub.uni-bremen.de/handle/elib/57An empirical dissolution index for planktonic foraminifera, XDX, was established based on the appearance of tests in computed tomography (CT) scans (Chapter 4). Calibrations between XDX and Delta[CO32-], Delta-mass (mass lost to dissolution) and Delta Mg/Ca (reduction in Mg/Ca due to dissolution) allow estimates of deep ocean Delta[CO32-] and also dissolution-corrected test mass and Mg/Ca (Chapter 5). Delta[CO32-] reconstructed for the deep (4,157 m) tropical western Indian Ocean (WIND28K) increased by ~25 µmol/kg over Termination I and ~15 µmol/kg over Termination II while dissolution maxima coincided with transitions to colder stages (Chapter 6). XDX-corrected Mg/Ca-derived SSTs were coolest during MIS 3. Minimum test mass in the corrected record coincided with the lowest temperatures. Comparison of two methods of cleaning foraminiferal tests from a depth transect (Chapter 7) found no offset in Mg/Ca between methods for G. sacculifer and P. obliquiloculata. Mg/Ca was decreased by reductive cleaning by ~4% for G. ruber and ~10% for N. dutertrei. Offset in Mg/Ca between the two methods was insensitive to preservation state.enBitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY)planktonic foraminiferadissolutionMg/CaSSTIndian OceanXDXreductive cleaningcomputed tomographyCT550Dissertationurn:nbn:de:gbv:46-00101815-15