Suprasubduction zone ophiolite fragments in the central Appalachian orogen: Evidence for mantle and Moho in the Baltimore Mafic Complex (Maryland, USA)

Abstract Suprasubduction zone (SSZ) ophiolites of the northern Appalachians (eastern North America) have provided key constraints on fundamental tectonic processes responsible for evolution Appalachian orogen. The central and southern Appalachians, which extend from New York to Alabama (USA), also contain numerous ultramafic-mafic bodies that been interpreted as ophiolite fragments; however, this interpretation is a matter debate, with origin(s) such occurrences attributed layered intrusions. These disparate proposed origins, alongside range possible magmatic affinities, varied potential implications orogen its relationship We present results field observations, petrography, bulk-rock geochemistry, spinel mineral chemistry ultramafic portions Baltimore Mafic Complex, refers series are discontinuously exposed in Maryland Pennsylvania (USA). Our data indicate Complex comprises SSZ fragments. Soldiers Delight Ultramafite displays geochemical characteristics—including highly depleted trace element patterns high Cr# spinel—characteristic subduction-related mantle peridotites serpentinites. Hollofield likely represents “layered ultramafics” form Moho. Interpretation an Iapetus Ocean–derived raises possibility broadly coeval suite preserved along thousands kilometers orogenic strike.