Carbonate dissolution in the deep SE Atlantic during the last 1.1 million years

Here we study the carbonate dissolution history of the deep SE Atlantic as evidenced in proxy records in Core T89-40 from the Walvis Ridge, spanning the last 1.1 million years. All dissolution proxy records (fragmentation index, ratio of planktonic and benthic foraminifera, sand fraction and number of planktonic foraminifera per gram sediment) show similar patterns, unique events, and these proxy records are strongly correlated with each other. These carbonate dissolution records are marked by enhanced amplitudinal variability during the early part of the Mid-Pleistocene Transition (MPT) around 960 ky, driven by increased interglacial preservation and enhanced glacial dissolution respectively. This pattern of global climate driven interglacial-glacial dissolution cycles became very pronounced during the last 600 ky. The higher frequency of the orbital cycle of obliquity, however, was also persistent in the carbonate dissolution proxy records. The presence of the orbital obliquity cycles in the dissolution proxy records of the SE Atlantic shows that the intensity of dissolution may be linked, at least partly, to high-latitude processes of deep-sea circulation and sea-ice extent. A strong interglacial dissolution event occurred during Marine Isotopic Stage (MIS) 13.11 within the so-called Mid-Brunhes Dissolution Interval. The preservation history of planktonic foraminiferal shells was little influenced by dissolution except for those shells within MIS 12 and