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Anticlinal
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Anticlinal may refer to: *Anticline, in structural geology, an anticline is a fold that is convex up and has its oldest beds at its core. *Anticlinal, in stereochemistry, a torsion angle between 90° to 150°, and –90° to –150°; see Alkane_stereochemistry See also *Weald–Artois Anticline * Mareuil Anticline * La Tour-Blanche Anticline *Usk Anticline *Fold (geology) *Detachment fold *Stereochemistry Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereois ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticline
In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the location where the curvature is greatest, and the limbs are the sides of the fold that dip away from the hinge. Anticlines can be recognized and differentiated from antiforms by a sequence of rock layers that become progressively older toward the center of the fold. Therefore, if age relationships between various rock strata are unknown, the term antiform should be used. The progressing age of the rock strata towards the core and uplifted center, are the trademark indications for evidence of anticlines on a geologic map. These formations occur because anticlinal ridges typically develop above thrust faults during crustal deformations. The uplifted core of the fold causes compression of strata that preferentially erodes to a deeper st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fold (geology)
In structural geology, a fold is a stack of originally planar surfaces, such as sedimentary strata, that are bent or curved 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''). Synsedimentary folds are those formed during sedimentary deposition. Folds form under varied conditions of stress, pore pressure, and temperature gradient, as evidenced by their presence in soft sediments, the full spectrum of metamorphic rocks, and even as primary flow structures in some igneous rocks. A set of folds distributed on a regional scale constitutes a fold belt, a common feature of orogenic zones. Folds are commonly formed by shortening of existing layers, but may also be formed as a result of displacement on a non-planar fault (''fault bend fold''), at the tip of a propagating fault (''fault propagation fold''), by differential compaction or due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkane Stereochemistry
In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted just by rotations about formally single bonds (refer to figure on single bond rotation). While any two arrangements of atoms in a molecule that differ by rotation about single bonds can be referred to as different conformations, conformations that correspond to local minima on the potential energy surface are specifically called conformational isomers or conformers. Conformations that correspond to local maxima on the energy surface are the transition states between the local-minimum conformational isomers. Rotations about single bonds involve overcoming a rotational energy barrier to interconvert one conformer to another. If the energy barrier is low, there is free rotation and a sample of the compound exists as a rapidly equilibrating mixture of multiple conformers; if the energy barrier is high enough then there is restricted rotation, a molecule may exist for a rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weald–Artois Anticline
The Weald–Artois Anticline, or Wealden Anticline, is a large anticline, a geological structure running between the regions of the Weald in southern England and Artois in northern France. The fold formed during the Alpine orogeny, from the late Oligocene to middle Miocene as an uplifted form of the Weald basin through inversion of the basin. The folding resulted in uplift of about , though concurrent erosion may have substantially reduced the actual height of the resulting chalk ridges. As is the case with all anticlines, older rock strata are found in the core of the structure. These are in this case Upper Jurassic and Lower Cretaceous strata. The western part of the ridge (the Weald of Kent, Sussex and Surrey in England) has been greatly eroded, with the presumed chalk surface removed to expose older, Lower Cretaceous rocks (Wealden Group) and a small area of Upper Jurassic Purbeck Beds. On the French side of the English Channel more Upper Jurassic rocks crop out in a small ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mareuil Anticline
The Mareuil Anticline, also called Mareuil-Meyssac Anticline, is a structural high within the sedimentary sequence of the northeastern Aquitaine Basin. The northwest-southeast trending anticline was caused by tectonic movements probably starting in the Upper Cretaceous. Description of the structure The anticline was named after Mareuil, a small town in the northwestern Dordogne, France. The centre of the structure is near Sainte-Croix-de-Mareuil, somewhat farther to the northwest. In plan view the anticline has the shape of an elongated pear with its long axis aligned NW-SE and reaching about 5 km in length (the Cenomanian/Turonian boundary serving as a reference horizon). The short axis is only 2 km in length. The structure is doubly asymmetric, with steeper dipping northeastern and northwestern limbs. It is accompanied on its northeastern side by the ''Mareuil Fault'', which starts at La Rochebeaucourt and continues to the north of Brantôme. Along this fault t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Tour-Blanche Anticline
The La Tour-Blanche Anticline, also called Chapdeuil Anticline or Chapdeuil-La Tour-Blanche Anticline, is a tectonically caused, dome-like upwarp in the sedimentary succession of the northeastern Aquitaine Basin in France. The structure is oriented west-northwest-east-southeast. Description of the structure The anticline was named after La Tour-Blanche, a small town in the northwestern Dordogne. Yet the centre of the structure is situated farther southeast within the commune of Chapdeuil, hence the names Chapdeuil Anticline or Chapdeuil-La Tour-Blanche Anticline. In plan view the structure has the shape of a nearly rectangular parallelogram with the base lines striking ESE-WNW (N 120) and the sides more or less N-S (reference horizon being the Ligérian/ Angoumian boundary). In its long dimension, the anticline measures about 6 km, yet across strike merely 3 km. Similar in shape to the Mareuil Anticline, the La Tour-Blanche Anticline has an asymmetric profile with a st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Usk Anticline
The Usk Inlier is a domed outcrop of rock strata of Silurian age in Monmouthshire in south-eastern Wales. It is located in the countryside between the towns of Caerleon and Pontypool and the village of Raglan. The longer axis of the dome or ' pericline', often referred to as the Usk Anticline, is aligned north–south. The inlier is largely surrounded by a sequence of Old Red Sandstone rocks of Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ... age, though both these and the Silurian rocks are largely obscured by superficial deposits.British Geological Survey 1:50,000 scale geological map sheets 232, 233, 249 & 250 (England & Wales series) References Anticlines Landforms of Monmouthshire Geology of Wales Rock formations of Wales {{Wales-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detachment Fold
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. By placing your left foot on one end and pushing (with your left foot) towards the other end of the rug, the rug slides across the floor ( decollement) and folds upward (detachment fold). Figure 1, is a generalized representation of the geometry assumed by a detachment fault. Definitions Detachment folding occurs as strain imposed on a mechanically weak layer or incompetent unit, such as shale or salt, or at the boundary between an incompetent and more competent unit, induces resistance from the units resulting in folding typically observed in the competent unit.Homza, T. and W. Wallace (1995) Geometric and kinematic models for detachment fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
