Open AccessDeep circulation changes in the Labrador Sea since the Last Glacial Maximum: New constraints from Sm‐Nd data on sediments
Author(s) -
Fagel Nathalie,
Innocent Christophe,
Stevenson Ross K.,
HillaireMarcel Claude
Publication year - 1999
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/1999pa900041
Subject(s) - geology , glacial period , oceanography , sedimentary rock , north atlantic deep water , deep sea , paleontology , ice sheet , marine isotope stage , thermohaline circulation , interglacial
Sm‐Nd concentrations and Nd isotopes were investigated in the fine fraction of two Labrador Sea cores to reconstruct the deep circulation patterns through changes in sedimentary supply since the last glacial stage. Three sources are involved: the North American Shield, Palaeozoic rocks from northeastern Greenland, and mid‐Atlantic volcanism. The variable input of these sources provides constraints on the relative sedimentary supply, in conjunction with inception of deep currents. During the last glacial stage a persistent but sluggish current occurred inside the Labrador Basin. An increasing discharge of volcanic material driven by the North East Atlantic Deep Water is documented since 14.3 kyr, signaling the setup of a modern‐like deep circulation pattern throughout the Labrador, Irminger, and Iceland basins. During the last deglacial stage the isotopic record was punctually influenced by erosion processes related mainly to ice‐sheet instabilities, especially 11.4, 10.2, and 9.2 kyr ago.