Mesozoic marine facies sedimentary rocks recently found in the Chaoshan Depression from the northeastern South China Sea consist of mudstone,sandstone,radiolarian siliceous rock,interbedded oosparite,and volcanics of Middle Jurassic to Cretaceous age.Their petrologic and sedimentary characteristics indicate that depositional environments shifted from shallow marine to deep marine,before returning back to continental facies.There was a sharp break between deep marine and continental facies, indicating a sedimentation hiatus.Thin basalt(spilite)layers are often interbedded in those deep marine radiolaria-bearing siliceous rocks.Paleoclimate turned from humid in the Middle Jurassic to Early Cretaceous to arid in the Late Cretaceous.The existence of these Mesozoic marine strata is very important for interpreting the tectonic evolution of this region and the influence of the Tethys tectonic domain on the Pacific tectonic domain during the Mesozoic.