Scorias are one of the major products of Paekdu (or Changbai) volcano, widespread distributed along numbers of scoria cones in Democratic People' s Republic of Korea. In the field, these rocks mainly appear as the unconsolidated porous pyroclastic, and the colour of pyroclastic deposits chang from red or red -brown at the surface to brown or grey to depth. In this study, we report an integrated dataset of major and trace elements for the scoriaes, and propose that scoriaes resulted from assimilation and fractional crystallization process of the mafic primitive basalt magmas. These volcanic rocks consist of basalt, trachybasalt, basaltic trachyandesite and trachyandesite, which are characterized by high Na2O + K2O (5.46% similar to 9.30%), SiO2 (46.22% similar to 55. 38%) and Al2O3 (15.28% similar to 22.11%), and relatively low MgO (2.05% similar to 4.94%) and FeOT (6.79% similar to 14.76%). Chondrite-normalized rare earth elements (REE) patterns display positive Eu anomalies. Primitive mantle -normalized incompatible trace elements diagrams exhibit strong enrichment in large ion lithophile elements (LILE) relative to highfield strength elements (HFSE) and display significantly negative Nb-Ti anomalies. Besides, differentiation index (DI) of the studied volcanic rocks ranges from 36. 93 to 64. 48, higher than those formed during craton - forming period; Their consolidation index (SI) ranges from 10. 73 to 24. 09, lower than those derived from early mantle basalts (SI = 25 similar to 45). These chemical characteristics indicate that the Paekdu volcanic rocks experienced high degree fractionation. Also, values of Nb/La, Sm/Nd, La/Nb and Ba/Nb ratios all scatter between the values of mantle basalts and continental crust, which imply obvious crustal contamination. We thus propose that the scoria of the study area might have formed through fractionation and crustal contamination during the ascending of basaltic magma from mantle.
