Macro fractures / joints and other structural featuresare commonly seen in geological formations 28. Similar features areuniversally disributed in many natural or synthetic materials in micro-levels.By collecting oriented sample and studying the attitudes of structural orplanar features including bedding planes; it is possible to measure their strikes anddip directions, dip amounts, plunge directions and plunging amounts.
From thesedata, it is possible to determine direction of weakness or direcion of movement and quantity ofpore-fluids through petrofabric investigations. Unlike fault or fracture planea joint plane is a break of material without lack of any movement. Generally, ajoint occurs as a set of joint system with specific orientation, spacing andjoint planes are parallel to each others.
The system is comprised with two or more intersecting joint sets.Micro-folds were formed by compressive movements and their axial planes arealigned along tensional forces. Sheet joints are formed by removal of overlyingmaterials or dissolution of overlyingmaterials. Similarly bedding planes and bedding joints are also guide fluid flow along horizontal directions 24.The fluid flow takes more residential time for its movement, reaction,deposition and evapoation of mineral materials along these horizontal planes.Therefore, it is necessary to study the planar features of sheet or beddingjoints. Fault planes, joint planes,cleavage planes and glide planes are set up weak planes formed by tensional movements.Cleavages and fractures are types of weak planar features that developed duringdeformations of materials.
Crack is an irregular break without completeseparation. Active and dormant cracks are seen even in synthetic materials. Ifthey are active, they show some movement in direction, width or depthover a measured period of time.
If the cracks are dormant, they remainunchanged. Cleavages are crystallographic faces along which minerals can easily split. Linearstructural features represent weak planes of materials. The dimension of theseplanes widely vary macro to microlevels controlling the flow of pore-fluids.The fluid retaining capacity is increased as the dimension of fracture planesdecreases.