Related Experiment Video
Updated: Nov 16, 2025

Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
Published on: August 31, 2017
Extreme isotopic heterogeneity in Samoan clinopyroxenes constrains sediment recycling
Jenna V Adams1, Matthew G Jackson2,3, Frank J Spera2
1Department of Earth Science, University of California Santa Barbara, Santa Barbara, CA, USA. adams@ucsb.edu.
Abstract:
Lavas erupted at hotspot volcanoes provide evidence of mantle heterogeneity. Samoan Island lavas with high 87Sr/86Sr (>0.706) typify a mantle source incorporating ancient subducted sediments. To further characterize this source, we target a single high 87Sr/86Sr lava from Savai'i Island, Samoa for detailed analyses of 87Sr/86Sr and 143Nd/144Nd isotopes and major and trace elements on individual magmatic clinopyroxenes. We show the clinopyroxenes exhibit a remarkable range of 87Sr/86Sr-including the highest observed in an oceanic hotspot lava-encompassing ~30% of the oceanic mantle's total variability. These new isotopic data, data from other Samoan lavas, and magma mixing calculations are consistent with clinopyroxene 87Sr/86Sr variability resulting from magma mixing between a high silica, high 87Sr/86Sr (up to 0.7316) magma, and a low silica, low 87Sr/86Sr magma. Results provide insight into the composition of magmas derived from a sediment-infiltrated mantle source and document the fate of sediment recycled into Earth's mantle.
More Related Videos
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
06:06Sediment Core Extrusion Method at Millimeter Resolution Using a Calibrated, Threaded-rod
Published on: August 17, 2016
Related Concept Videos
Speciation Rates
Diversity of Archaea IV
Diversity of Archaea II
Diversity of Archaea III
Diversity of Protists III
Diversity of Archaea I