Geochemical Characteristics of Early Cretaceous Shoshonites in the Middle and Western Northern Margin of the North China Craton and A Comparative Study
Early Cretaceous potassium-riched alkaline volcanic rocks were discovered in the Suhongtu area, Inner Mongolia. These volcanic rocks display higher total alkaline contents(K2 O+Na2 O=5.20%~8.92%), K2 O/Na2 O(K2 O/Na2 O=0.59~1.03) and TiO2(1.59%~2.05%) and characteristics of shoshonites series rocks. Chondrite normalized rare earth element patterns and primitive mantle normalized trace element patterns show slightly positive and negative Eu anomalies(δEu=0.88~1.11) and the enrichment of large ion lithophile ...