Abstract: The genetic mechanism of earthquake was discussed based on geological, geophysical and geochemical data and energy estimation. Highenergy fluids derived from the core and mantle can provide enough thermal energy for magma generation, earthquake formation and geothermal field; but rocks cannot accumulate enough strain energy to produce a strong earthquake. The strong and great earthquakes (M≥6.0) are mainly distributed in the trench, volcanic island arc and continental rift zones and other tensile structural belts in the world, such as the western Pacific Ocean trench, the eastern Indian Ocean trench, the midocean ridge, the rift valley in eastern Africa, the Mediterranean SeaBlack SeaCaspian SeaPersian Gulf tensile zone, and the Ise LakeAla KulUbud LakeSuzukur LakeLake Baikal rift valley in the eastern Eurasian continent. Fluids play an important role in the movement of mantle and crust as well as activities of earthquake and volcano. Cryptoexplosive breccias that have been found all over the world indicate the cryptoexplosion was pervasive in the geological history. Explosion occurred in the process of deep fluid upward migration towards the earth surface, resulting in earthquakes of different magnitudes and focal depths in the earth interior. Therefore, the crytoexplosion can be considered as the predominant mechanism of earthquake generation. The generation of various types of earthquakes that occurred in discontinuous and anisotropic inelastic media, such as the moderate and deepfocus earthquakes, earthquake swarm, slow earthquakes and nodipolecouple earthquakes, can be explained by the proposed model. The model can also much better explain the spatial overlap of earthquake, volcanic and geothermal zones in the world as well as formation of cryptoexplosive breccias associated ore deposits.

Key words:  cryptoexplosion, earthquake, deep fluid, thermal energy, strain energy