The size of plume heterogeneities constrained by Marquesas isotopic stripes

A groundbreaking study reveals that the Marquesas Islands, part of Polynesia's UNESCO World Heritage Site Te Henua Enata, are composed of two distinct isotopic stripes with significantly different chemical and isotopic compositions. These stripes, identified through new Sr, Nd, Pb, Hf isotopes, and trace element data from lavas across several islands, suggest that the isotopic heterogeneity originates within the plume itself rather than the ambient mantle. The research proposes that these stripes stem from partial melting of two adjacent filaments in small 'plumelets' originating from a large dome structure deep in the mantle. This finding contrasts with more productive hotspots like Hawaii or Réunion, where higher degrees of melting obscure such isotopic variability.

Chauvel, C., Maury, R. C., Blais, S., Lewin, E., Guillou, H., Guille, G., Rossi, P., & Gutscher, M.-A. (2012). The size of plume heterogeneities constrained by Marquesas isotopic stripes. Geochemistry, Geophysics, Geosystems, 13(7). Portico. https://doi.org/10.1029/2012gc004123