News

The peridotite section of supra-subduction zone ophiolites is often crosscut by pyroxenite veins, reflecting the variety of melts that percolate through the mantle wedge, react, and eventually crystallize in the shallow lithospheric mantle. Understanding the nature of parental melts and the timing of formation of these pyroxenites provides unique constraints on melt infiltration processes that…

Emmanuel Codillo (now PhD student in Le Roux’s group) just published the work he performed as an undergraduate guest student at WHOI! The mechanisms of transfer of crustal material from the subducting slab to the overlying mantle wedge are still debated. Mélange rocks, formed by mixing of sediments, oceanic crust, and ultramafics along the slab-mantle…

A great outreach event with geobiologist collaborator Joan Bernhard. This spring, we introduced students at the Perkins School for the Blind to foraminifera, or forams: small, single-celled organisms that abound in ocean waters and seafloor sediments. Joan collected a variety of forams which were scanned using x-ray micro-computed tomography in the Mantle Rocks lab. The computer models were then enlarged,…

Alicia ‘Cici’ Cruz-Uribe (WHOI postdoc 2014-2015) has just published her work on melange melting in Geology. https://pubs.geoscienceworld.org/gsa/geology/article/528313/generation-of-alkaline-magmas-in-subduction-zones “Here we report results from experiments in which natural mélange materials were partially melted at upper mantle conditions to produce alkaline magmas. Partial melts produced in our experiments have trace-element abundance patterns that are typical of alkaline arc lavas,…

The SCARF 2017 student-led cruise is back on shore! After a few days in the Azores we sailed across the mid-Atlantic ridge aboard the R/V Neil Armstrong and acquired bathymetry, gravity and magnetics data along a flow line. It was an amazing adventure! SCARF 2017: A modern-day transatlantic crossing

Emily just started a Doherty Postodoctoral scholar at WHOI and is working on (U-Th)/He thermochronology and trace element geochemistry to 1) date magnetite that form during fluid alteration, 2) investigate the geochemical fingerprints of serpentinization at different tectonic settings, and 3) constrain the thermal history of mantle peridotites. Emily has extensive experience with anything outdoorsy…

Taylor comes from Brown University and is a 2017 Summer Student Fellow working on the formation of pyroxenites in the Josephine Ophiolite (Oregon). He is using EPMA, LA-ICP-MS, REE closure temperatures and Nd isotopes by MC-ICP-MS to decipher the timing of vein formation in the mantle.

Ben Urann (PhD student in Le Roux’s group) just published his work on SIMS developments and halogen budgets of the Earth’s mantle! The fluorine (F) and chlorine (Cl) contents of arc magmas have been used to track the composition of subducted components, and the F and Cl contents of MORB  have been used to estimate…

Constraining the scale and the nature  of mantle heterogeneities is critical to understand mantle dynamics, but there is still limited information available on the mechanisms and timing of formation of mantle heterogeneities observed in exhumed mantle rocks. Most of those heterogeneities are layered pyroxene-rich veins that form as a result of melt focusing and subsequent…

First-row transition element (FRTE) concentrations in primitive mantle-derived melts have been used as direct indicators of mantle source mineralogy (e.g., Ti, Mn, Fe, Co, Ni, Zn) and as proxies to trace the oxidation state of the mantle (e.g., Sc, V, Cu, Zn). Ga and Ge, which share chemical similarities with FRTEs, may also have the…