The patterns of geomorphic processes are determined by the exogenic and endogenic forces, will differ according to the changes in climate, geography, morphology, lithology, terrain both natural and anthropogenic activities.
Endogenic Processes
The term endogenic describes the energy radiating from within the earth that is responsible for shaping Earth’s geomorphic features. Endogenic processes or endogenesis manifests itself through rock dynamics and rock deformation, which include flowage, mass movement , and plastic flow.
Diastrophism
All processes that move, elevate or build up portions of the earth’s crust come under diamnophism. They include: (i) orogenic processes involving mountain building through severe folding and affecting long and narrow belts of the earth’s crust; (ii) epeirogenic processes involving uplift or warping of large parts of the earth’s crust; (iii) earthquakes involving local relatively minor movements;
Orogeny is a mountain building process whereas epeirogeny is continental building process.
Through the processes of orogeny, epeirogeny, earthquakes and plate tectonics, there can be faulting and fracturing of the crust. All these processes cause pressure, volume and temperature (PVT) changes which in turn induce metamorphism of rocks.
Volcanism
Volcanism includes the movement of molten rock (magma) onto or toward the earth’s surface and also formation of many intrusive and extensive volcanic forms.
Exogenic Processes
Exogenic forces are said to be active in the early stages of the earth’s evolution. These forces were increased by large meteorites and comet impacts. These hits on the early earth led to its heat up, reducing the earth’s elasticity resulting in floods, floods which later helped in depositing materials in low elevations.
All the exogenic geomorphic processes are covered under a general term, denudation. The word ‘denude’ means to strip off or to uncover.
Weathering, mass wasting/movements, erosion and transportation are included in denudation.
The basic reason that leads to weathering, mass movements, and erosion is development of stresses in the body of the earth materials.
