Domains of depleted mantle : new evidence from hafnium and neodymium isotopes
Data Set S1: The Hf and Nd isotopic compositions of the mid-ocean ridge basalts and ocean island basalts. (121Kb)
Figure S1: Distribution of locations of mid-ocean ridge basalts which show correlation between Hf and Nd isotopic compositions. (1.541Mb)
Salters, Vincent J. M.
Hart, Stanley R.
Langmuir, Charles H.
MetadataShow full item record
Isotope systematics of basalts provide information on the distribution of mantle components and the length scale of mantle heterogeneity. To obtain this information, high data and sampling density are crucial. We present hafnium and neodymium isotope data on more than 400 oceanic volcanics. Over length scales of several hundred to over one thousand kilometers hafnium and neodymium isotopes of mid-ocean ridge basalts are correlated and form an array of parallel trends on a global scale. On a larger scale these domains differ in the amount of highly depleted mantle material with radiogenic hafnium and neodymium isotope ratios. Compared to the Atlantic and Indian Ocean basins the asthenosphere of the Pacific basin seems to have a more uniform and a less radiogenic Hf isotopic composition for a given Nd isotopic composition. The parallel arrays of mid-ocean ridge basalts provide strong constraints on the makeup of the MORB mantle and are evidence for the presence of a highly depleted and highly radiogenic neodymium and hafnium component. This component, because of its highly depleted character, is unrecognized in the strontium-neodymium-lead isotope systems alone. Alternatively, the parallel arrays can have an ancient origin of systematic variations in the degree of depletion. Each array then represents the variations in this fossil melting regime. Individual ocean island basalt suites display different slopes in hafnium-neodymium isotope space, which are also best explained by varying amounts of highly residual mantle rather than isotopic differences in enriched mantle components as previously invoked. The ocean island basalt arrays diverge at the depleted end and project to radiogenic compositions that are similar to those of the asthenosphere through which they travel. This is strong evidence that the plume material interacts with its surrounding mantle as it ascends. The isotopic compositions of the ocean island and ridge basalts suggest that their systematics are influenced by a heretofore unrecognized depleted component.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 12 (2011): Q08001, doi:10.1029/2011GC003617.
Suggested CitationArticle: Salters, Vincent J. M., Mallick, Soumen, Hart, Stanley R., Langmuir, Charles H., Stracke, Andreas, "Domains of depleted mantle : new evidence from hafnium and neodymium isotopes", Geochemistry Geophysics Geosystems 12 (2011): Q08001, DOI:10.1029/2011GC003617, https://hdl.handle.net/1912/4790
Showing items related by title, author, creator and subject.
Dynamic intermediate ocean circulation in the North Atlantic during Heinrich Stadial 1 : a radiocarbon and neodymium isotope perspective Wilson, David J.; Crocket, Kirsty C.; van de Flierdt, Tina; Robinson, Laura F.; Adkins, Jess F. (John Wiley & Sons, 2014-11-20)The last deglaciation was characterized by a series of millennial-scale climate events that have been linked to deep ocean variability. While often implied in interpretations, few direct constraints exist on circulation ...
Neodymium isotopes and concentrations in aragonitic scleractinian cold-water coral skeletons - modern calibration and evaluation of palaeo-applications Struve, Torben; van de Flierdt, Tina; Burke, Andrea; Robinson, Laura F.; Hammond, Samantha J.; Crocket, Kirsty C.; Bradtmiller, Louisa I.; Auro, Maureen E.; Mohamed, Kais J.; White, Nicholas J. (Elsevier, 2017-01-27)Cold-water corals (CWCs) are unique archives of mid-depth ocean chemistry and have been used successfully to reconstruct the neodymium (Nd) isotopic composition of seawater from a number of species. High and variable Nd ...
Peucker-Ehrenbrink, Bernhard; Miller, Mark W.; Arsouze, Thomas; Jeandel, Catherine (American Geophysical Union, 2010-03-27)Realistic models of past climate and ocean chemistry depend on reconstructions of the Earth's surface environments in the geologic past. Among the critical parameters is the geologic makeup of continental drainage. Here ...