Fold (geology) - Wikipedia
网页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).
1.5: Folds - Geosciences LibreTexts
网页A line drawn through all the hinge points of a fold is called the axial trace of the fold. (It’s also called the hinge trace, which is arguably a better term because the trace has little relation to the fold axis, but most structural geologists use axial trace.)
9.4: Folds - Geosciences LibreTexts
网页The hinge line follows the line of greatest bend, where the axial plane intersects the outside of the fold. Geologic folds are layers of rock that are curved or bent by ductile deformation. Folds are most commonly formed by compressional forces at depth, where hotter temperatures and higher confining pressures allow ductile deformation to occur.
13.2: Folds - Geosciences LibreTexts
网页2024年5月16日 · A fold consists of limbs that meet at the hinge zone. An axial surface bisects the fold along the hinge zone. The axial trace is where the axial surface intersects another surface, such as the top of a bed.
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FOLDS - ETH Z
网页Folded single surface - basic geometrical definitions. A proliferation of terms has developed to describe the considerable variation of fold morphology. For convenience, it is easier to first define folds on a single surface. Morphology of a folded surface: Hinge, limb, inflections.
13.2 Folds – Physical Geology, First University of Saskatchewan …
网页A fold consists of limbs that meet at the hinge zone. An axial surface bisects the fold along the hinge zone. The axial trace is where the axial surface intersects another surface, such as the top of a bed.
网页by 1) similar fold geometry, in particular thinning at limbs and (relative) thickening at hinges; 2) stretching lineations parallel to fold hinges; 3) commonly disharmonic folding; 4) common apparent relationship between layer thickness and competency and wavelength and style of folding. Passive flow folding can do (1) but utterly fails
E. Folds – Geological Structures: a Practical Introduction
网页Based on their shape, fold hinges can be classified as angular or rounded. (There are more sophisticated classifications but these will do for our purposes.) Closing direction: synforms and antiforms. If the limbs dip away from the hinge, then the fold closes upward; we say the fold is an antiform.
网页typically characterized by 1) similar fold geometry, in particular thinning at limbs and (relative) thickening at hinges; 2) stretching lineations parallel to fold hinges; 3) commonly disharmonic folding; 4) common apparent relationship between layer thickness and competency and wavelength and style of folding.
Folds - Geology Science
网页2023年3月2日 · Folding is a type of ductile deformation that occurs when rocks are subjected to compressive stress, causing them to deform and bend without fracturing or breaking. The process of folding can result in a variety of fold geometries, including anticlines, synclines, domes, and basins.