Neodymium isotopic composition of deep-sea corals from the NE Atlantic: implications for past hydrological changes during the Holocene

摘要: The Nd isotopic composition of deep-sea corals (Lophelia pertusa and Madrepora oculata) located on the Rockall Bank at a depth 747 m was investigated to reconstruct past hydrological changes North Atlantic. coral 3Nd values ranged from � 15.4 11.9 demonstrate strong systematic during Holocene, most likely reflecting in seawater 3Nd. record displays general trend, with small decrease 14.1 15.2 time interval 9400 6000 yrs followed by an abrupt increase towards more radiogenic values, ranging 13.9 11.9. These variations imply relative proportions upper-intermediate waters originating subtropical subpolar Atlantic, which are characterised today 10.4/� 11.5 15, respectively. Therefore, we suggest that reef frameworks forming reveals evidence mid-Holocene mid-depth gyre circulation. A wider eastward extension gyre, induced stronger westerlies, less intense deepwater formation Labrador Sea occurred early-mid-Holocene. Supposedly, larger amounts freshwater were carried underneath Nordic seas. Similar today, freshening may have been offset reinforcement NAC higher salinities water masses contributing inflow. Beyond yrs, weakening triggered saline eastern increasing potential for deep convection reducing contribution Atlantic basin-scale re-circulation seas Such modifications could affected deep-water convective activity northern hemisphere through redistribution early-Holocene melting northern-hemisphere ice sheets.