A review of anomalous rare earth elements and yttrium in coal
As described by Zhang (1993) and the China Coal Geology Bureau (1996), a widespread coal covering a total area of ~ 70,000 km 2 was deposited in a peat swamp that developed on the mafic tuffs in a continental environment (China Coal Geology Bureau, 1996). The mafic tuff generally exhibits positive Ce anomalies (Fig. 4 A).
