PowerPoint Presentation

Geology PresentationPresented by-

Bhanu Mitra (R080114012)Rakesh Kumar (R080114027)

Folds & Faults

Talk OutlineStrike and DipForces behind deformationsFold and typesFaults and typesImportance of structuresTrapsAnticline and Fault traps

When working in the field, Strike and Dip measurements are used to determine the orientation of rock units and other features

Strike The compass direction of a line at the intersection of a geologic plane and a horizontal plane (water line)Dip The angle between the inclined plane and horizontal, perpendicular to strike

Strike & Dip

Forces behind deformations:TensionalCompressionalShear

It is one of the most common geological structures found in rocks. When a set of horizontal layers are subjected to compressive forces, they bend either upward or downward. The bend noticed in rocks are called folds.It occurs when originally horizontal rock units deform under compressive forces.

Fold

Types of fold

Syncline Sinks Down

Anticline Up in the Air

SynclineAnticline

Syncline & Anticline Folds

Some more folds

FaultsA fault is when tension and compression associated with plate movement is so great that blocks of rock fracture or break apart. This process can occur very rapidly, in the form of earthquakes.

Types of FaultNormal Fault : Hanging wall moves down with respect to footwall.

Reverse Fault : Hanging wall moves upward with respect to footwall.

Strike Slip Fault : Two blocks slide pass each other because of shear stress.

Is this fault right-lateralor left-lateral?Left-lateral

Why are these folds and faults important ?The study of geologic structure has been prime importance in petroleum exploration.Folded and faulted rock strata commonly form traps for the accumulation and concentration of petroleum and natural gas.

TrapsStructural traps

A trap is a trap, whether or not it has a mouse in it" (attributed to W. C. Finch, in Rittenhouse, 1972, p. 16).The structural and stratigraphic configuration that focuses on oil and gas into an accumulation.Two critical components of a trapSealReservoir rock.Structural traps are created by the syn- to post depositional deformation of strata into a structure that permits the accumulation of hydrocarbons in the subsurface. The resulting structures involving the reservoir, and usually the seal intervals, are dominated by either folds, faults or any combination of the foregoing.

Anticlinal Trap

A fold structure with an arch of non-porous rock overlying porous strata (reservoir rock), providing a trap in which oil, gas, or water may accumulate.

Fault TrapFaults can be extremely important to the viability of a trap by providing either seals or leak points.They are capable of acting as top, lateral, or base seals by acting as sealing surfaces due to the impermeable nature of the material along the fault.

Thank You for your patience!!!

Structural Geology :It is the study of factors such as origin, occurrence, classification, type and effects of various primary structures like folds, faults etc. and are different from those primary structures such as bedding, which develop in rocks at the time of their formation.Structural geology is the study of rocks deformed by stress and strain.

Normal FaultBack

Reverse FaultBack

Strike-Slip FaultBackLeft LateralRight Lateral