anticline


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Related to anticline: monocline

fold

fold, in geology, bent or deformed arrangement of stratified rocks. These rocks may be of sedimentary or volcanic origin. Although stratified rocks are normally deposited on the earth's surface in horizontal layers (see stratification), they are often found inclined or curved upward or downward. Arches, or upfolds, in stratified rock are called anticlines; depressions or downfolds, synclines. A third type of fold, the monocline, is a steplike structure sloping in one direction only. It is more correctly called a flexure and generally passes at depth into a fracture called a fault. An imaginary line drawn along the crest of an anticline or the trough of a syncline is its axis; the two sides curving away from the axis are the limbs. If both limbs, dipping in opposite directions, make the same angle with the horizontal, and if an imaginary axial plane passed through the axis and the center of the fold is vertical and divides the fold into two equal halves, the fold is symmetrical; if the limbs make unequal angles, and if the axial plane is inclined and does not bisect the fold, the fold is asymmetric. If one limb lies partly under the other, and the axial plane is inclined, the fold is overturned; if one limb lies almost completely under the other, and the axial plane is almost horizontal, the fold is recumbent. The axis of a fold cannot be indefinitely extended parallel to the horizontal, but plunges or emerges as the fold tapers off to a plane. Certain domes are very short anticlines with axes plunging at both ends, while some basins, similarly, are synclinal structures. Folds are commonly formed at some distance below the surface, but complete folds or portions of folds are exposed by erosion. Anticlines frequently have their crests eroded, till only the worn-down stumps of the two limbs remain. In a similar manner synclines may be eroded so that only the edges of the limbs project above the surface. The ridge crests of the Appalachian Mts. are eroded limbs of folds. The nature of the original fold can generally be determined from the arrangement of the outcrops, or exposed portions; thus, two outcrops dipping toward each other mark a syncline, and two outcrops dipping away from each other, an anticline. Folds on a grand scale, extending, for example, most of the length of a continent, are known as geosynclines and geanticlines. The immediate cause of folding is generally conceded to be the horizontal compression of the earth's surface, anticlines being squeezed up by this compression and synclines formed between anticlines. The problem of the ultimate cause of fold formation is similar to that of fault formation, both being earth movements involved in mountain building and plate tectonics. Porous and permeable rocks of anticlines often contain oil and gas reservoirs. Organic remains of late Paleozoic tree fern swamps were converted to anthracite coal during the folding of the Appalachian Mts.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Anticline

 

a fold of stratified rocks which is convex upward. The bending point of the strata is called the anticlinal hinge. The surface connecting the bendings of all the strata composing the anticline is called the axial surface, and the sides of the anticline are called limbs. Depending on the position of the axial surface and the direction of the incline of the limbs, an anticline may be vertical, inclined, overturned, or recumbent. According to the configuration, it is possible to distinguish a linear anticline in which the lengtn is significantly greater than the width, a brachyanticline in which the length is somewhat greater than the width, and a dome in which the length and width are approximately equal.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

anticline

[′an·ti‚klīn]
(geology)
A fold in which layered strata are inclined down and away from the axes.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

anticline

a formation of stratified rock raised up, by folding, into a broad arch so that the strata slope down on both sides from a common crest
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
Further the southwestern limb of the Muzaffarabad anticline physically shows fresh fault breccia, mylonite and gouge line and their downwardflow revealing the recent active nature ofthis thrusted anticline.
Numerous subordinate traps are formed by the antithetic faults affecting the rollover anticline. In addition, the shales associated with the roll-over faults are commonly over-pressured and diapiric, adding to structural development in the over-burden and increasing the seal on faults.
The economic geology of Kaha-Harand section of Mari anticline represents many economic commodities.
In addition, small-scale historic hard-rock workings have been identified a further 400m to the west of the Banner prospect (ASX release 23 August 2018) along the interpreted Fountain Head anticline. This suggests there is potential for further gold mineralisation in this area2.
The exploration target is gold mineralisation associated with subsidiary structures adjacent to the Ballard and Mt Ida Shears within the Kurrajong Anticline. The Mt Ida South Project is located within the Mt Ida Greenstone Belt on the Kurrajong anticline directly south of the Copperfield granite (Figure 8).
As we move forward, we are highly confident in Denbury's position and are committed to executing our strategic plan, including the significant ongoing EOR development at the Cedar Creek Anticline. Through leveraging our resilient, high margin, low decline asset base, we will continue to drive incremental, high value growth opportunities.
Drainage patterns of Zindapir Anticline (ZA), Sakhi Sarwar (SS), Sulaiman Foredeep (SF) and Kingri Fault (KF) areas were generated using Strahler order of streams.
The settlers in Cagayan Valley (750,000 BC), in the Cabalwan anticline, or in Palawan Tabon Cave (50,000-60,000 BC)?
The intensity of a rock burst and the resulting damage are more prominent in abnormal stress areas of anticline structures.
In the constructed numerical model, the basic simulation grid consisted of 51 cells in the I-direction and 51 cells in the J-direction, with 6 layers (in both the anticline model and the flat model) (Figure 1).
They frequently have a roll-over anticline with four-way closure on the down-thrown side of the fault and antithetic faulting in the down-thrown block.