Eclogites and garnet pyroxenites: Similarities and differences

Eclogites and garnet pyroxenites are genetically linked to basaltic precursors. Traditionally garnet pyroxenites are linked to fractionation of basaltic Magmas Over a range of mantle pressures and more recently they have been implicated in the genesis of ocean islands. in contrast eclogites are linked to the subduction of slab basalt and gabbro precursors which may be hydrothermally altered. Recently this subduction paradigm has been questioned. We present mineralogical, trace element and O isotopic data for eclogites and garnet pyroxenites that reveal some similarities but also important chemical and isotopic differences that support a distinct provenance (i.e., age and process). Continent…