Geology

Geology Deformation of Rocks- When rocks are put under directed pressures, they may respond to the applied pressure in several ways: 1. Folding or bending 2. Faulting of fracturing Stress Stress = Force / area Concepts of Force and Stress Force : An action exerted by one body on another Force= mass x acceleration Stress: A force acting upon a surface is referred to as pressure or stress. Rocks are affected by four kinds of stress which differ in their directional properties. 1. Compressional Stress: Occurs when a rock is squeezed and the opposing forces are directed toward one another. 2. Tensional Stress: Develops when a rock is pulled apart, with the forces directed away from each other. 3. Shear Stress: Generated along planes parallel to the deforming forces. Planes are being pushed adjacent to each other. Ex. Cali. 4. Hydrostatic Stress: Stress is applied equally on all surfaces of a body is referred to as hydrostatic stress or confining pressure. Ex: Diamonds, earth’s core. Concept of Strain Strain: The change in size and shape of a body resulting from the action of an applied stress field. Expressed as Dilation or distortion or a combination of both. Dilation—Delta = V1-Vo/Vo----- Hydrostatic stress Distortional strains are associated with shape change can be studied into two kinds: A. Longitudinal Strain--- e= L1-Lo/Lo B. Shear Strain--- stress, water, deformation, applied, stresses, strain, body, rocks, rock, pressure, material, table, shape, saturated, move, forces, ex, change, zone, through, three, tends, strains, strain, sediment, said, resulting, released, referred, rapidly, plastic, planes, original, one, kinds, hydrostatic