Holocene Environments in the Reykjanes Ridge Area, North Atlantic, Based on Micropaleontological Data

New data on the stability of marine systems and manifestation of the Holocene thermal optimum as a modern interglacial in the eastern part of the North Atlantic Subpolar Gyre were obtained. Interpretation of micropaleontological data from the AMK-325 sediment core and reconstructed summer sea paleotemperatures revealed the peculiarities in the development of the local environment in the last 10.8 ky. The rapid transition in the Early Holocene 10.1–9.3 ka to a warm state almost up to the modern level occurred in accordance with regional and global paleoclimatic archives. The subsequent strongly pronounced cold interval 8.2–7.3 ka is consistent with the global cooling “8.2 ka,” but was much longer. The establishment of optimal conditions with an increase in water temperature by 1.5–2°C above modern values was noted in the second half of the Middle Holocene 6.8–4.9 ka, later than the global Holocene optimum.