Fig. 1: Geological map and tectonic setting of the area studied.

a Map showing main Precambrian tectonic divisions of the North China Craton (modified from Kusky et al.13). Red box shows location of Zanhuang Complex, illustrated in (b); (b) Map showing the main tectonic zones of the Zanhuang Complex, with simplified profile (no vertical exaggeration) along fold nappe/thrust belt (a, b), showing the relative positions of the Eastern Block (EB) basement and unconformably overlying passive margin. The forearc upper-plate units include the Buddha nappe, thrust over the passive margin along a major thrust (suture) marked by the schistes lustrés, and this is succeeded structurally upwards by the Black Rock Temple nappe, which is overthrust by the Wutai/Fuping arc (WFA) system along the MORB-bearing ophiolitic mélange zone. WZD Western Zanhuang Domain, EZD Eastern Zanhuang Domain, CZD Central Zanhuang Domain. Map (b) modified from Wang et al. and Kusky et al.12,13,16,21,23.