Developments in our Understanding of Upper Mantle Derived from Peridotites

The upper mantle of the earth is believed to be largely composed of peridotite. Although we cannot access the upper mantle directly, slices or fragments of the upper mantle occur in the accessible portions of the earth’s crust as oceanic lithosphere (ophiolites), alpine massifs, and xenoliths of peridotite in alkali basalts and kimberlites. Geochemical and petrologic studies of these peridotites have resulted in developing our present understanding of the compositon and evolution of the upper mantle: the upper mantle appears to be depleted (relative to models for “primitive” mantle) of relatively incompatible elements and isotopic studies show that the depletion is relatively old.Historically geochemical studies of upper mantle peridotites have utilized major and trace element abundances. Particularly revealing have been studies utilizing incompatible trace element ratios and established isotope systems (e.g. Sr, Nd, Pb). Recently novel isotopic ratio analyses (e.g., Ni, Zn or Ca isotopes, for example) of peridotites are constraining processes and evolution of the upper mantle. For example, Ni isotopic compositions were recently used to model melting in the mantle Ca isotopic compositions were used to constrain source of metasomatic fluids that affected garnet peridotie xenoliths in kimberlites of the Slave Craton and Zn isotopic compositions determined magmatic inputs into volcanic lakes.The journal solicits a range of article topics including original research and review (but not limited to) contributions on mantle geochemistry based on studies of mantle-derived peridotites:• Applications of novel isotopic systems• Applications of established isotopic stystem (e.g., Sr, Nd or Pb)• Novel applications of trace element ratios• Use of major element ratios in new approaches• Other geochemical studies of mantle peridotites Topic editors: Michael Roden, Alexandra Yang Yang, Manu Prasanth. M.P, Vincent Salters Source: https://www.frontiersin.org/research-topics/79863/developments-in-our-understanding-of-upper-mantle-derived-from-peridotites