摘要
esozoic volcanic rocks developed on the basement of the Precambrian block and Hercynina orogenic belt surrounding Songliao basin. The volcanism was actived from Early Jurassic to Late Cretaceous with its peak time in J3-K1 and the rock types are dominated by high K calcalkaline series, partly consisting of shoshonitic and calcalkaline series. Mesozoic volcanism of studied area may result from decompression melting accompanying uneven extension wide spread at a large area corresponding to the formation of grabens without contemporaneous subduction in J3-K1. The basic volcanics and their differentiates came from an enriched lithospheric mantle. While in K2 the extensional center concentrated at Songliao basin and the equivalent products are basalts rich in Na and poor in K and the magma generated from the top of asthenosphere about 60 km. During this time large Songliao depression was developed.
esozoic volcanic rocks developed on the basement of the Precambrian block and Hercynina orogenic belt surrounding Songliao basin. The volcanism was actived from Early Jurassic to Late Cretaceous with its peak time in J3-K1 and the rock types are dominated by high K calcalkaline series, partly consisting of shoshonitic and calcalkaline series. Mesozoic volcanism of studied area may result from decompression melting accompanying uneven extension wide spread at a large area corresponding to the formation of grabens without contemporaneous subduction in J3-K1. The basic volcanics and their differentiates came from an enriched lithospheric mantle. While in K2 the extensional center concentrated at Songliao basin and the equivalent products are basalts rich in Na and poor in K and the magma generated from the top of asthenosphere about 60 km. During this time large Songliao depression was developed.
