Fig. 1From: Growth mechanisms and environmental implications of carbonate concretions from the ~ 1.4 Ga Xiamaling Formation, North Chinaa Major tectonic subdivisions of China (modified from Tang et al. 2017); the box showing the area illustrated in panel b; b Simplified map showing the location of the study area; c Simplified geological map of the study area (modified after the 1:200,000 Geological Map of China, The China Geological Survey 2013)Back to article page