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6942149 
Journal Article 
Origin of Early Pleistocene basaltic lavas in the Erdaobaihe River basin, Changbaishan region 
Ma HanRui; Yang QingFu; Pan XiaoDong; Wu ChengZhi; Chen Cong; , 
2015 
SCIENCE PRESS 
BEIJING 
31 
11 
3484-3494 
WOS:000367026900023 
The origin of Early Pleistocene basaltic lavas in the Erdaobaihe River basin is studied on the basis of petrochemistry and isotopic analysis. The results show that the basaltic lavas are composed of potassium trachybasalt, basaltic trachyandesite and soudium tholeiite. The lavas have similar REE patterns, suggesting that they came from the same source. The Sr, Nd and Pb isotopic tracers indicate that the magma source of the basaltic lavas is mostly close to primitive mantle. Their Mg(sic)( =100Mg(2+)/( Mg2+ + Fe2+) <60) are lower than that ( =60 similar to 68) of the primary magma of the Early Pleistocene basalts in eastern China. Their Ni contents (27. 76 x 10(-6) similar to 200. 6 x 10(-6)) are less than that of primary mantle, whereas their Rb/Sr (0. 05 -0. 09) and Ba/Rb ratios (15. 64 similar to 264) are greater than those of the primary mantle. All lines of evidence indicate that these lavas were originated from evolved magma. The parental magma is potassium trachybasaltic magma. The DI value of the lavas varies from 42 to 67, and the lavas are characterized by high Ca and Sr contents, and positive Eu anomaly in REE patterns. Trace element plots show that the basalts retain the trend of partial meting, while the trachybasalt and basaltic trachyandesite exhibit the trend of crystal fractionation. It is likely that different degree of crustal contamination has occurred during the process of magmas ascending. The Nb/Ta ratio of the basaltic rocks (14. 8 similar to 15. 8) in this region is similar to that of basaltic rocks from the Kamchatka deep subduction zone. Nb/Ta-( Na2O-K2O) plots indicate that the generation of the basaltic magma is related to the partial meting of subducted slab. 
Early Pleistocene basaltic lava; Behavior of magma Source; Magma origin; Tectonic setting; Changbaishan region