Basin and range extensional tectonics at the latitude of las vegas, nevada brian wernicke. Unfortunately, this book cant be printed from the openbook. Public domain topics comparison, computer programs, free flow, mach number, separated flow, subsonic flow, three dimensional flow, convergentdivergent nozzles, experiment design, predictions, pressure gradients, propulsion system configurations. Backarc basins are regions of extension behind subduction zones and are often locations where volcanoes form.
Extensional tectonics of the outer hebrides fault zone, south. Aulacogen an unsuccessful rift that cuts across a continental margin at a high angle to the margin. Extensional tectonics in the caledonides hardangerfjord shear zone figure 2. Burchfiel department of earth and planetary sciences, massachussetts institute of technology, cambridge, ma 029, u. Extensional tectonism may form during as well as after the contractional history of a collisional orogeny.
Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. The sverdrup basin originated due to an episode of extensional tectonics that affected much of the caledonianellesmerian orogenic belt in early. This type of tectonics is found at divergent plate boundaries, in continental rifts, during and after a period of continental collision caused by the lateral spreading of the thickened crust formed. At the junction between an oceanic transform fault and the adjacent ridge segments, there is normally a curved fabric. The tectonics of the fault zone on south uist are dominated by structures associated with several episodes of pervasive topdowntothese to ene brittle extensional deformation, which are progressively overprinted by protophyllonitic and phyllonitic fabrics associated with topdowntothee to ene extension. Arundian synrift sequence more than 4 km thick includes footwallderived. Lecture notes structural geology earth, atmospheric, and. Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere deformation styles.
Drilling through an extensional normal fault encounters a stratigraphic gap. Proprietary seismicreflection profiles show a system of downtotheeast precambrian extensional faults. Extensional tectonics and collapse structures in the suez rift egypt. The relationship of extensional and compressional tectonics. Sometime after the first and before the start of the second episode of. Find materials for this course in the pages linked along the left. Any synorogenic extensional deformation must have occurred prior to the onset of this extensional history, which is dated to circa 405 ma. Another widespread setting for extensional tectonics are upper plates above subduction zones subjected to. Study of the structures formed by, and the processes associated with, the stretching of a planetary bodys crust. Dec 22, 2019 extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. Extensional tectonics in the vicinity of a transform fault in.
Pdf extensional tectonics in the himalayan orogen, zanskar. The central and southern appalachians have a long history of interrelated extensional and compressional tectonics. On the moon, extensional tectonic features have only been observed close to the influence of the mare basaltfilled basins and floorfractured craters. Rifting the process by which continental lithosphere undergoes extensional deformation stretching by the formation and activity of normal faults. Dec 08, 2011 this file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. The chosen examples all have in common a distributed extensional deformation and a high heat flow, thus a weak crust and thin lithosphere. Geological society, london, special publications geometry. Compressional metamorphic core complexes, lowangle normal. The title extensional tectonics of centralnorthern mexico reflects a fraction of studies on mexican country, which are summed up in a research sponsored by the ministry of education and the national council for science and technology and identified with number 167638. Recent extensional tectonics on the moon revealed by the lunar reconnaissance orbiter camera. The lithosphere lithosphere is comprised of the upper mantle and the crust, the outer shell of the earth.
Compressional and extensional tectonics in lowmedium. Tension fractures and extensional tectonics nature. Extensional tectonics, a slab window and the arrival of. The earth is composed of layers of different composition and physical properties, principally the solid central core, the fluid peripheral core, the viscous mantle, and the solid. A curve with a negative gradient results, and the intercept of the curve with the ordinate defines the null point. Basin and range extensional tectonics at the latitude of. Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere. Compressional and extensional tectonics in lowmedium pressure granulites from the larsemann hills, east antarctica volume 2 issue 2 c. Tectonics, in situ stress stress, faults and rock failure. Upper miocenelower pliocene extension in mt parnon was. The shape of this curve is a result of extensional tectonics, and gradient changes record vari. Extensional tectonics wikimili, the free encyclopedia. Sedimentary models for extensional tiltblockhalfgraben basins. The majority of the chapter is devoted to a discussion of stretching processes that affect the whole lithosphere and are driven by the relative motion of lithospheric plates.
Rifting, seafloor spreading, and extensional tectonics. Several episodes of granite magmatism are recorded, culminating in the late. Longer aftershocks duration in extensional tectonic settings. Extensional tectonics is associated with the stretching and thinning of the crust or the lithosphere. Predictive permeability model of extensional faults in crystalline. The menderes massif in western anatolia was exhumed initially as an asymmetric core complex in the early miocene due to extension beginning in the oligocene and then the central. Peloponnesus in the southwestern part of the aegean is formed by a heterogeneous pile of alpine thrust sheets that was reworked by normal faulting from upper miocene to recent times. Extensional tectonic regimes are therefore primarily associated with divergent i. The trollaskagi peninsula is located just south of the junction between the kolbeinsey ridge and the tjornes fracture zone and offers a rare opportunity for studying the three. Extensional tectonic regimes are primarily associated with divergent plate boundaries, but can also commonly be found in plate interiors in the form of localized rift zones and extensional basins. Extensional tectonic environment a region of the earths crust or lithosphere that is spreading apart due to tectonic forces acting on the surrounding areas. Extensional tectonics in the caledonides of southern norway, an overview torgeir b.
A characteristic pattern of normal faults that we have studied in several regions illustrates successive geometries relating to increasing amounts. Download and read free online basin and range extensional tectonics near the latitude of las vegas, nevada memoir geological society of america by brian p. If you need to print pages from this book, we recommend downloading it as a pdf. An animated tectonic reconstruction of southwestern north america since 36 ma nadine mcquarrie brian p. Analysis of structural traps in extensional settings.
Three broad geometrickinematic types can be defined. Since middle pliocene, the axial part of this foldthrust belt underwent an extensional tectonics. The course covers the field level all the way up to basinscale architecture, and the role of salt and strikeslip tectonics in the development of extensional basins. Extensional crustal tectonics and crustmantle coupling, a. Front matter continental tectonics the national academies. Kt magmatism and basin tectonism in western rajasthan, india, results from extensional tectonics and not from reunion plume activity kamal k. It underlines the role of extensional tectonics during sedimentation. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses.
Kinematic studies combined with various age constraints in the southern scandinavian caledonides have revealed an extensional history which started by hinterland. Extensional tectonics fall 2005 1 the jargon of extensional tectonics for the following terms, draw a simple illustrative diagram consisting of either a map and crosssection or a block diagram. The model predicts significant extensional deformation in regions with surface heat flow 65 mwm 2 subjected to a tensile tectonic force of 3. Faulting and faultrelated processes key issues in earth sciences on free shipping on qualified orders. Extensional tectonics and collapse structures in the suez.
Lecture notes section contains class notes for the topic covered in the lectures. Extensional definition and meaning collins english. Basins that form within an extensional tectonic setting are characterized by the development of depressions, bounded by normal faults, within. Extensional tectonics and stratigraphy of the north atlantic margins authors a. Extensional tectonics in the caledonides of southern. Recently released industry seismic data image a 6 km thick dinantian succession in the stainmore basin, and are used to interpret deposition in response to extensional subsidence. Rotational normal fault a normal fault whose hanging wall block rotates around a horizontal axis during slip. Subsidence the sinking of the surface of the lithosphere.
Normal faults form in divergent plate boundaries, areas of gravitational collapse and extension above salt domes. Ashton embry, benoit beauchamp, in the sedimentary basins of the united states and canada second edition, 2019. Granite magmatism and extensional tectonics in southern. Geological and geophysical interpretation of the rio. Modes of extensional tectonics brian wernicke and b.
The eastern margin of the gulf of suez displays spectacular interrelationships between riftborder fault systems and sedimentation patterns. Extensional tectonics and sedimentation, eastern gulf of. There are still many important questions of extensional tectonics. We have analysed potential field data gravity and magnetic from the argentine to the brazilian oceanic basins and extending over the. Article pdf available in geological society london special publications 741. Sharma government postgraduate college, sirohi rajasthan 307001 india email. Rifts are regions in which extensional tectonics i. An animated tectonic reconstruction of southwestern north. Geological society, london, special publications geometry and. Wikipedia definition extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust or lithosphere. Divergent extensional tectonic regimes springerlink.
The first type comprises low angle dip extensional faults which exhibit listric. Pdf on jun 1, 2010, ibrahim cemen and others published extensional tectonics in the basin and range, the aegean, and western anatolia. Structural geology, tectonics and geodynamics form a coherent and interdependent. We attempt, by means of quantitative theoretical analysis guided by real geological examples, to establish some ground rules for interpreting extensional phenomena. Lecture notes structural geology earth, atmospheric. The identification of early cretaceous, riftoblique extension that predated the main rifting event in the barmer basin. A systematic comparison of experimental setups for. Extensional tectonics is concerned with the structures formed by, and the tectonic processes. Although hundreds of papers have been devoted to the geometric and kinematic analysis of compressional tectonic regimes, surprisingly little has been written about the details of largescale strain in extended areas. Faults which postdate variscan contractional deformation are ubiquitous in south cornwall. Typically, aulacogens transect the grain of an orogen that borders the margin. Extensional tectonics and stratigraphy of the north. Pdf continental extensional tectonics researchgate. The basin is bounded to the north by the lunedalewigglesworthbutterknowle en echelon suite of normal faults.
Hancock and others published continental extensional tectonics find, read and cite all the research you need on researchgate. Extensional tectonics an overview sciencedirect topics. Extensional tectonics and salt structures, maribshabwa. It is proposed that each episode was controlled by a reactivation of a fracture system in the precambrian basement. Rifting, seafloor spreading, and extensional tectonics geokniga. View extensional tectonics research papers on academia. Aulacogens may represent failed arms of threearmed rifts, or they may simply be older rifts formed long before the development of the continental margin, during an earlier episode of rifting at a different.
Pdf extensional tectonics in the basin and range, the aegean. This first episode of extension left the cms with the normal ocotillo canyon fault and a related graben containing nonmarine syn extensional sediments lower part of the split mountain group. The types of structure and the geometries formed depend on the amount of stretching involved. Kt magmatism and basin tectonism in western rajasthan. Received 1 september 1981, accepted in revised form 10 march 1982. Extensional tectonics in the himalayan orogen, zanskar, nw india. Pdf on oct 11, 2015, jesus galindozaldivar and others published extensional tectonics, graben development paper find, read and cite all the research you need on researchgate. Tectonics presents original research articles that describe and explain the evolution, structure, and deformation of earths lithosphere including across the range of geologic time. Pdf extensional tectonics, graben development paper.
Box 1047, blindern, n0316 oslo, norway received 24 october 1995. Your chance to have a onetoone lesson with bestselling language expert paul noble, try a free audio sample of his brand new mandarin chinese course. Abstract this paper discusses the geological and geophysical interpretation of rift structures in the region extending from the rio grande rise, in the southeastern brazilian margin, towards the cabo frio high, which separates the campos and santos basins. Sedimentary models for extensional service email alerting new articles cite this article click here to receive free email alerts when request permission part of this article click here to seek permission to reuse all or subscribe collection london, special publications or the lyell click here to subscribe to geological society, notes. As the surface of the earth is stress free, the component of simple shear must be transmitted from below and implies a displacement of the crust relative to the mantle. Abstract we investigate the feedbacks between surface processes and tectonics in an extensional setting by coupling a 2. Wernicke division of geological and planetary sciences, ms 10023, california institute of technology, pasadena, ca 91125 abstract we present tectonic reconstructions and an. Regional tectonics are extensional and there is little structural evidence for earlier crustal thickening. Recent extensional tectonics on the moon revealed by the.
Late to postvariscan extensional tectonics in south cornwall. The fact that lowangle normal faults exist in both extensional and compressional tectonic settings, and can actively slip at low angles extensional tectonics workshop course summary extensional structures provide some of the worlds largest known oil reservoirs and remain one of the major frontier plays of the immediate future, both onshore and, particularly, in deep water offshore. Extensional tectonics wikipedia republished wiki 2. This type of tectonics is found at divergent plate boundaries, in continental rifts, during and after a period of continental collision caused by the lateral spreading of the thickened crust formed, at releasing bends in strikeslip faults, in backarc basins, and on the continental end of.
Extensional tectonics free online course materials. The structural and sedimentological evolution of a 100 km. Apr 01, 2000 read extensional tectonics in the caledonides. The remaining por tions of the orogenic wedge are dominated by rocks of the jotun nappe, which is a major fragment of mostly crystal line proterozoic crust that appears to have been thrust for more than 300 km e. Andersen institutt for geologi, universitetet i oslo, p.
Previously unrecognised extensional tectonics exposed in. In terms of plate tectonics, extension systems are associated with. Pdf extensional tectonics in mt parnon peloponnesus. The aegean region western anatolia, aegean sea and greece is one of the areas of the earth under the effect of extensional tectonics and includes the typical features of core complexes in this type of region.
The section reproduced convincingly demon strates that parts of a given hanging wall may remain unrotated while other parts may rotate in opposite direc tions. Strikeslip faulting is a common mode of deformation in both continental and oceanic crust and. Modes of extensional faulting controlled by surface processes. Longer aftershocks duration in extensional tectonic.
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