Continental Collision
Continental collision is a process of two continents pushing each other, which leads to the growth of a mountain belt. When a subduction at a convergent plate boundary happens, oceanic lithosphere of a subducting plate slides beneath the overriding plate, which consists of either oceanic or continental lithosphere. Since the latter is denser and cooler than the asthenosphere, subduction happens, and the lithosphere is pulled down into the mantle (Marshak 00:00:24). The continental crust then slips beneath the edge of the overriding plate. Rock that gets to the internal part of the mountain belt goes much deeper and undergoes metamorphism, and the stress makes rocks fold. Thrust folds are developed, and slices of the crust are pushed up and over other slices.
Rock Deformation
Rock deformation includes shearing, stretching, shortening, bending, and breaking of rocks, resulting in various geological structures. Three ways of rock deformation are elastic, brittle, and ductile ones. The former means that elastic solids can easily deform due to stress and then return to their original shape (Norton Geology, “Rock Deformation”). Some may be slightly elastic and then begin to deform brittly or ductily. Brittle deformation is fracturing of rocks that were elastic to a certain point. Finally, ductile deformation means that rocks were elastic when the stress was applied and then remained their new shape.
Types of Folds
Fold appears when stress causes rock layers to bend or warp. Folds are divided into anticlines, synclines, and monoclines (Norton Geology, “Types of Folds”). Anticlines are folds that have an arch-like shape. Synclines are folds with a trough-like shape. Finally, monoclines are step-shaded folds that result from reactivation of the fault buried at depth.
Works Cited
Marshak, S. “Continental Collision.” W. W. Norton & Company, Web.
Norton Geology. “Rock Deformation.” W. W. Norton & Company, Web.
“Types of Folds.” W. W. Norton & Company, Web.