Backstripped tectonic subsidence curves show a threefold subdivision of. To accommodate the separation, dominantly normal faults and even open fissures lead to stretching, rupture and lengthening of. Globalscale control of extensional tectonics on co 2 earth. Extensional collapse of orogens extensional collapse of orogens dewey, j. 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. It is also the equivalent of the strain parameter stretch low beta factor. Rifts a rift or chasm is an example of extensional tectonics. Progressive excision and dismemberment of the ophiolite link to major fabrics in the core complexes and gradual focusing of extensional basins.
A combination of the upb shrimp and zircon fissiontrack analyses has been used to constrain the age and evolution of the extensional tectonics in the betic cordilleras, southern spain. Plasienka geological institute, slovak academy of sciences, slovakia keywords. New constraints on extensional tectonics and seismic hazard. If the stress field is oriented with the maximum stress. Our antivirus check shows that this download is malware free. Since the development of the theory, geologists have had to reexamine almost every aspect of. Backarc basins are regions of extension behind subduction zones and are often locations where volcanoes form. Divergent extensional tectonic regimes springerlink. The older supradetachment basin formed on the gediz detachment fault, and its sediments are cut by highangle normal faults that controlled the formation of the. Each type of interaction causes a characteristic set of earth structures or tectonic features.
Start this article has been rated as startclass on the projects quality scale. Extensional tectonics and stratigraphy of the north atlantic margins authors. Extensional tectonics an overview sciencedirect topics. Compressional and extensional tectonics in lowmedium. Synergy of tectonic geomorphology, applied geophysics and. Extensional tectonics is part of wikiproject geology, an attempt at creating a standardized, informative, comprehensive and easytouse geology resource. Extensional tectonics and gravitational collapse in an ordovician passive margin. Ashton embry, benoit beauchamp, in the sedimentary basins of the united states and canada second edition, 2019. Extensional tectonic environment a region of the earths crust or lithosphere that is spreading apart due to tectonic forces acting on the surrounding areas. Extreme isotopic variation documents extensional tectonics in arc. A characteristic pattern of normal faults that we have studied in several regions illustrates successive geometries relating to increasing amounts. Variscan intraorogenic extensional tectonics in the ossamorena zone evoraaracenalora del r. Stretching is generally measured using the parameter.
The major fault trend is the ns arabian trend which has produced repeated basement horsts and grabens due to extensional tectonics. The types of structure and the geometries formed depend on the amount of stretching involved. The suez rift is a 300 km long and 50 to 80 km wide basin which cuts a granitic and metamorphic shield of precambrian age, covered by sediments of paleozoic to. Extensional tectonics and gravitational collapse in an. The central and southern appalachians have a long history of interrelated extensional and compressional tectonics. Tectonic, sedimentation and magmatism of the canterbury basin, new zealand. Carbon dioxide is one of the most abundant natural gases in the world. While it is generally agreed that the strength of a planets lithosphere is controlled by a combination of brittle sliding and ductile flow laws, predicting the geometry and initial characteristics of faults due to failure from stresses imposed on the lithospheric strength envelope has not been thoroughly explored. Continental drift, sea floor spreading and plate tectonics plate tectonics is a theory developed in the late 1960s, to explain how the outer layers of the earth move and deform. There are still many important questions of extensional tectonics. Extensional tectonics and stratigraphy of the north atlantic margins. 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. Rifting, seafloor spreading, and extensional tectonics. In fact, the location on the footwall of a regional normal fault system, together.
Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary bodys crust. Rifts are regions in which extensional tectonics i. Extensional tectonics have been the dominant mode of deformation controlling the timespace evolution of magmatism at mt. Extensional tectonic regimes are therefore primarily associated with divergent i. The extensional tectonic setting of n attica led to the development of several ew trending normal faults west of the attica detachment. The relationship of extensional and compressional tectonics. The principal detachment shear zone is the xtmzt sz, which is located betweenthenhmbandthendmcb. Style of volcanism and extensional tectonics in the.
Phyllosilicate injection along extensional carbonatehosted. The shape of this curve is a result of extensional tectonics, and gradient changes record vari. Variations in the geometry, distribution and thickness of cambrian igneous and sedimentary units within southwest oklahoma are related to a late proterozoic. The lithosphere lithosphere is comprised of the upper mantle and the crust, the outer shell of the earth. The westdipping cyclopicsalt spring washlakeside mine fault system marks the easternmost boundary of the extensional allochthon in the basin and range province and the eastern limit of exposure of midtertiary igneous rocks at the latitude of lake mead. This 18chapter volume is small enough to focus on the interplay among tectonics, sedimentation, and petroleum systems. Extensional tectonics and stratigraphy of the north atlantic. The sverdrup basin originated due to an episode of extensional tectonics that affected much of the. 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. A rift or chasm is an example of extensional tectonics where the crust of the earths lithosphere is being pulled apart. These extensional faults predate folding because they were breached by flexuralslip faults and, as a result of their passive rotation in fold limbs, these initial normal faults may now appear as reverse faults, particularly.
However, in order for the magma to ascend to the surface and build new lithosphere, the earlier formed crust must be pulled apart and fractured to create a new magma pathway. Trench fill extensional collapse faulting region of under plating 1 t. Geological society, london, special publications geometry. The tectonics of the coso range has been described as having arcuate and ring faults both of which suggest the presence of a circumscribed subsidence bowl or calderalike feature. Basin and range extensional tectonics at the latitude of las vegas, nevada. Extensional tectonics and sedimentary response of the earlymiddle.
Extension systems are zones where plates split into two or more smaller blocks that move apart. Lecture notes structural geology earth, atmospheric. This plate motion causes them to collide, pull apart, or scrape against each other. Extreme isotopic variation documents extensional tectonics in arc magmas from methana, greece. Pdf continental extensional tectonics researchgate. Simplified upper palaeozoic geology of south cornwall modified after leveridge et al. Detrital rutile ages can deduce the tectonic setting of. Hancock and others published continental extensional tectonics find, read and cite all the research you need on researchgate. Therefore, rapid extensional tectonic activity appears to be present along this mountain front and the process of forming the triangular facets should be quite recent. Late to post variscan extensional tectonics figure 1. Stimulated by the wealth of frontier exploration data and deep seismic surveys about the north atlantic margins, this publication was crafted to provide a comprehensive analysis of north atlantic extension. Pdf extensional tectonics of centralnorthern mexico. Basin and range extensional tectonics near the latitude of.
Compressional and extensional tectonics in lowmedium pressure granulites from the larsemann hills, east antarctica. The influence of tectonics on sedimentation and hydrocarbon accumulation is different among extensional, strikeslip, and contractional structural styles. Earthquake ground motions in extensional tectonic regimes. The theory has caused a revolution in the way we think about the earth. Rift valleys are characterized by a central linear downfaulted segment a graben with a parallel rightflank uplifts. Pdf extensional tectonics in the basin and range, the aegean. Extensional tectonics and collapse structures in the suez.
The upper plate of this fault system is exposed only in the northern white hills, mohave county, arizona. Note that there has been no indication of rupture along the pineios fault system after the damaging earthquake of june 2008 konstantinou et al. Purchase of an open document does not constitute license for republication in any form, nor does it allow web posting without prior written permission. For best results viewing and printing pdf documents, it is recommended that you download the documents to your computer and open them with adobe. It is proposed that each episode was controlled by a reactivation of a fracture system in the precambrian basement. Quantitative subsidence analysis of the mesozoic evolution of the. However in the last 20 yr several moderate size earthquakes m 5. Hence constructive plate boundaries are regions of extensional stresses and extensional tectonics. The actual developer of the free software is university of colorado, department of physics. Miocene extensional tectonics and fluid flow across the. Oct, 2011 rather, we interpret the 40 ar 39 ar ages of white mica with lowd values to date syn.
Gps observations imply that the area is characterized by a strain rate of about 3050 nstrain a. In some instances, these shear bands also indicate a dextral component of displacement conjugate sinistral shear bands are occasionally observed. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. Extensional tectonics and stratigraphy of the north. This file is licensed under the creative commons attributionshare alike 3. The process of fracturing, injection and eruption is repeated frequently. Rift rift system a belt of continental lithosphere that is undergoing, or has undergone, extensional deformation i. Insights into extensional events in the betic cordilleras.
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. Windows 10 3264 bit windows 8 3264 bit windows 7 3264 bit windows vista 3264 bit windows xp 3264 bit file size. A curve with a negative gradient results, and the intercept of the curve with the ordinate defines the null point. Three deformation events related to extensional tectonics are distinguished in the study area. Continental drift, sea floor spreading and plate tectonics. The baja california peninsula separation resulted from tectonic processes related to extensional activity in centralnorthern mexico, which formed the midgulf of california rise mgcr. If you would like to participate, you can choose to edit this article, or visit the project page for more information. The structure of the earth, plate tectonics and landforms.
Convergent or collisionalrelated tectonics generally results in regional barrovianstyle metamorphism, in contrast to extensional tectonics where any associated metamorphism if present at all is lowpressure in nature. Extreme isotopic variation documents extensional tectonics. Tension fractures and extensional tectonics nature. Proprietary seismicreflection profiles show a system of downtotheeast precambrian extensional faults. Georef subject arabian peninsula asia cenozoic cretaceous faults mesozoic oman mountains plate tectonics semail ophiolite tectonics tertiary. The theory of plate tectonics was influenced by alfred wegeners hypothesis of continental drift, introduced in 1915. The sverdrup basin originated due to an episode of extensional tectonics that affected much of the caledonianellesmerian orogenic belt in early carboniferous. The basin was uplifted and deformed in late eocene due to compression associated with the opening of. Plate tectonics the earths crust is divided into plates which are moved in various directions. Data presented in this paper suggest the tectonism of the coso range is in transition between stresses from the rightslip san andreas faultplate interaction, and.
Shrimp zircon uthpb geochronology request a copy link to publisher version. Extensional crustal tectonics and crustmantle coupling, a view from the geological record. Pdf extensional tectonics of the cordilleran foreland. Pdf extensional tectonics, graben development paper. D1 is a ductile deformation related to the exhumation of the mcc. Stretching reduces the thickness and horizontally extends portions of the crust andor lithosphere. Extreme isotopic variation documents extensional tectonics in. You may do so in any reasonable manner, but not in. An animated tectonic reconstruction of southwestern north america since 36 ma. Riftdrift transition the time at which active rift faulting ceases and seafloor spreading begins i. Extensional tectonics and the timing and formation of. Upload file developer services openei is developed and maintained by the national renewable energy laboratory with funding and support from the u. Extensional tectonics, graben development paper data pdf available. In the saudi offshore portion of the persian gulf, nesw, leftlateral strikeslip faulting of the basement is also important in forming oilfield structures.
For example, the formation of evaporated brines and extensional tectonics seem to have played an important role in the epigenetic basemetal mineralization on the lennard shelf of western australia do. View extensional tectonics research papers on academia. Overprinting of the basin of the middle and upper miocene esmeralda formation in western nevada by younger structural basins. An extensional fault is a fault caused by stretching of the earths crust.
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