*3.2. Dissolution Assesment*

Because of the immediate impact of dissolution on shell mass, a multiproxy approach was applied to determine the preservation state of the foraminiferal carbonate because indirect dissolution proxies may respond to influences other than dissolution alone. First, the conventional fragmentation index (F.I.) was counted in a sub-split of (~300) particles from the 315–355 µm sieve fraction. Subsequently, 30 of the weighed specimens was mounted for ultrastructural examination under the SEM using the *G. bulloides* dissolution index (BDX′ ). As this species has a high dissolution susceptibility ranking [29], it is a reliable indicator of the foraminiferal carbonate preservation state. The BDX′ [30] is based on the direct assessment of corrosion of the specimen's surface and consists of distinct dissolution stages that are determined by the decreasing preservation state of the four ultrastructural test features: pores, interpore space, spines, and ridges. As dissolution proceeds, pores are widened, the interpore areas are etched, and ridges and spines become denuded until the specimen is finally broken down. It thus consists of six stages worsening from 0 to 5, with severe dissolution starting above stage 3. The SEM analysis was performed with a Zeiss DSM 940A SEM in the Department of Geosciences at the University of Bremen.
