GEOCHEMICAL CHARACTERISTICS AND TECTONIC BACKGROUND OF BASALT FROM TAMULANGOU FORMATION IN NORTHERN DAXINGANLING
ZHANG Yu1,2, ZHAO Huan-li3, HAN Yan-dong3
1. China University of Geosciences, Beijing 100083, China; 2. Heilongjiang Institute of Regional Geological Survey, Harbin 150036, China; 3. Qiqihar Branch, Heilongjiang Institute of Regional Geological Survey, Qiqihar 161005, China
Abstract：Study on the petrology, geochemistry and tectonic setting of the basalt from Tamulangou formation indicates that the basic volcanic rocks are geochemically similar to both tholeiitic basalt and alkali basalt, with Na2O-22O, nonegative Eu anomaly, La/Yb=35.7, rich Ba, Sr and K, and deficient Nb. The magma is probably generated by rifting. In such a thermal-tectonic event, it is speculated that the crust in Shangheilongjiang area and the lithosphere in Huzhong area were thinned greatly; while the lithosphere and the crust in Genhe area were slightly thinned.
2005, Vol. 14 
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