Fig. 4: Field photographs illustrating field relationships and lithological characteristics in the Buddha and Black Rock Temple nappes, Zanhuang Complex.

a Folded amphibolites of picritic-boninitic composition from the picrite-boninite unit of the Back Rock Temple nappe; b tight to isoclinally folded picritic-boninitic metabasite (dark layer) with magnetite-quartzite (light layer, interpreted as meta-hydrothermal chert); c detail of picritic-boninitic metabasites crosscut by trondhjemite dike; d recumbent nappe with parasitic folds of tholeiitic basalt composition resting upon the thrust fault defined by the schistes lustrés layer. Note that this is an oblique view with highly curved hinge surfaces that vary from the core to the outside of the fold structure: e tholeiitic metabasalts and biotite-quartzite gneiss disposed in a large-scale recumbent fold in the Buddha nappe (one layer is outlined with white dashed line); f the variably-thin schistes lustrés layer, marking the thrust (suture) between the allochthonous IAT tholeiites of the Buddha nappe (above) and the autochthonous siliciclastic metasediments of the passive-margin sequence below; g detail of the contact (along yellow pencil) of the schistes lustrés thrust zone with overlying allochthonous Buddha nappe, represented by folded tholeiitic basalts. Pencil (yellow) is on the top of the schistes lustrés thrust zone. h Footwall metasediments of the passive-margin sequence in the Buddha nappe intruded by 2.53 Ga mafic sills and Paleozoic dolerite dike.