Compositional diversity in chromitites from Eastern Rhodopes (SE Bulgaria): petrogenesis and tectonic implications

In the Eastern Rhodopes (SE Bulgaria) the low-Al and low-Ti chromite forming chromitite bodies at Yakovitsa and Avren West massifs, and the high-Al and variable Ti chromite forming chromitite bodies at Golyamo Kamenyane (low-Ti) and Chernichevo (high-Ti) occur hosted within a representative ophiolitic mantle sequence formed in a mid-oceanic ridge, which evolved to an island arc/back-arc setting in a supra-subduction zone. Such conclusion is drawn from the diversity of MORB and boninitic affinity of the unaltered chromite cores, deduced from major element distribution in chromite and lithology of the ultramafic massifs.