Search results
Results from the WOW.Com Content Network
In structural geology, a fold is a stack of originally planar surfaces, such as sedimentary strata, that are bent or curved ("folded") during permanent deformation. Folds in rocks vary in size from microscopic crinkles to mountain-sized folds. They occur as single isolated folds or in periodic sets (known as fold trains).
A detachment fold, in geology, occurs as layer parallel thrusting along a decollement (or detachment) develops without upward propagation of a fault; the accommodation of the strain produced by continued displacement along the underlying thrust results in the folding of the overlying rock units. As a visual aid, picture a rug on the floor.
In geology, 3D fold evolution is the study of the full three dimensional structure of a fold as it changes in time. A fold is a common three-dimensional geological structure that is associated with strain deformation under stress .
The thin-skinned style of deformation is typical of many fold and thrust belts developed in the foreland of a collisional zone or back arc of a continental volcanic arc. This is particularly the case where a good basal decollement exists, usually in a weaker layer like a shale, evaporite, or a zone of high pore fluid pressure. [2]
When the limbs of a fold converge upward, the fold is referred to as an antiform. Conversely, when the limbs of a fold converge downward, the fold is known as a synform. Not to be confused with these terms (antiform and synform), the terms anticline and syncline are used in the description of the stratigraphic significance of the fold.
For example, when mixed sandstone and mudstone sequences are folded during very-low to low grade metamorphism, cleavage forms parallel to the fold axial plane, particularly in the clay-rich parts of the sequence. In folded alternations of sandstone and mudstone the cleavage has a fan-like arrangement, divergent in the mudstone layers and ...
For economic geology such as petroleum and mineral development, as well as research, modeling of structural geology is becoming increasingly important. 2D and 3D models of structural systems such as anticlines, synclines, fold and thrust belts, and other features can help better understand the evolution of a structure through time.
In structural geology, a syncline is a fold with younger layers closer to the center of the structure, whereas an anticline is the inverse of a syncline. A synclinorium (plural synclinoriums or synclinoria ) is a large syncline with superimposed smaller folds. [ 1 ]