➁Xie Guisheng, 1983, Explanatory Text for 1∶200 000 Scale Geological Map: Xinglonggou Sheet, Humazhen Sheet ➂Songmaoshan in Xinglonggou Area, Huma County, Heilongjiang Province ➃For rhythmic beds composed of sandstone, metamorphic sandstone and slate ➄Late Ordovician....