MESOZOIC INTRUSIVE ROCKS IN WESTERN LIAONING: Basic characteristics and their relations to the tectonic movement

The Mesozoic magmatic activities and tectonic movements are intensive in Western Liaoning region, with broadly distributed intrusive rocks. The rock bodies, occurring in different forms, with complex types, are concentrated in four NNE-or NE-trending belts. The intrusions are divided into three periods, i.e. Indosinian, Early Yanshanian and Late Yanshanian. In each period, the magma evolved from intermediate-basic to acidic. The distributions of magmatic activities are controlled by the E-W, NE and NNE structural systems. The Mesozoic magmatic cycles are closely related to the multistage and multi-phase of crustal movement. The magmatic activities can be divided into six peak periods, respectively corresponding to the six tectonic phases. The regional fault depression and compression formed the magmatic rock with different sources, compositions and emplacing ways.