Abstract The Spontang ophiolite forms the highest tectonic thrust slice above the Mesozoic–Early Tertiary continental margin of the north Indian plate in the Ladakh‐Zanskar Himalaya. Detailed field mapping, combined with geochemical analysis, has defined two major units: a full ophiolite sequence (Spontang ophiolite) overlain by an upper unit consisting of >500‐m‐thick basalt‐andesite volcanic and volcano‐sedimentary rocks of island arc affinity (Spong arc). The Spontang ophiolite comprises a harzburgitic mantle sequence, gabbroic and ultramafic cumulates, isotropic gabbros, and highly tectonized sheeted dikes feeding pillow lavas, with a few uncommon highly fractionated plagiogranites. A separate lherzolitic peridotite unit, affected by possible transform‐related shearing, was thrust over the harzburgites in the west, possibly during the early stages of subduction initiation beneath the ophiolite. Whole‐rock geochemistry and U‐Pb geochronology show that the ophiolite formed at a normal mid‐ocean ridge sp...