The Teton – Wind River domain: a 2.68–2.67 Ga active margin in the western Wyoming Province

2006 ◽  
Vol 43 (10) ◽  
pp. 1489-1510 ◽  
Author(s):  
B Ronald Frost ◽  
Carol D Frost ◽  
Mary Cornia ◽  
Kevin R Chamberlain ◽  
Robert Kirkwood
Keyword(s):  
Plate Tectonics ◽  
Accretionary Prism ◽  
Granulite Facies ◽  
Isotopic Data ◽  
Active Margin ◽  
Magmatic Arc ◽  
Wind River Range ◽  
Teton Range ◽  
Wyoming Province ◽  
Back Arc

The Archean rocks in western Wyoming, including the Teton Range, the northern Wind River Range, and the western Owl Creek Mountains, preserve a record of a 2.68–2.67 Ga orogenic belt that has many of the hallmarks of modern plate tectonics. A 2683 Ma tholeiitic dike swarm is undeformed and unmetamorphosed in the western Owl Creek Mountains. In the Wind River Range, these dikes have been deformed and metamorphosed during thrusting along the west- to southwest-directed Mount Helen structural belt, which was active at the time that the 2.67 Ga Bridger batholith was emplaced. In the northern Teton Range, the Moose Basin gneiss, which contains relict granulite-facies assemblages, appears to have been thrust upon the amphibolite-grade layered gneiss. The syntectonic Webb Canyon orthogneiss was intruded into the thrust at or before 2673 Ma. We interpret these relations, along with isotopic data indicating that the layered gneiss in the Teton Range consists of juvenile components, to indicate that the western Wyoming Province was the site of active margin tectonics at 2.68–2.67 Ga. This involved a magmatic arc in the present Wind River Range and back-arc spreading in the Owl Creek Mountains. The immature, juvenile layered gneiss in the Teton Range probably represents an accretionary prism or fore-arc basin onto which high-pressure rocks containing a mature sedimentary sequence were thrust at 2.67 Ga. Although it may be questioned as to when modern-style plate tectonics began in other cratons, it was certainly operating in the Wyoming Province by 2.67 Ga.

scholarly journals Precambrian Geological Evolution of the Teton Range, Western Wyoming

1999 ◽  
Vol 23 ◽  
pp. 85-87
Author(s):  
Kevin Chamberlain ◽  
B. Frost ◽  
Carol Frost
Keyword(s):  
National Park ◽  
Plate Tectonics ◽  
Crustal Growth ◽  
Ongoing Research ◽  
Grand Teton National Park ◽  
Basement Rocks ◽  
First Case ◽  
Peraluminous Granites ◽  
Teton Range ◽  
Wyoming Province

The crystalline rocks that form the core of the Teton Range are part of the Wyoming Province, which is one of the oldest portions of North America. Study of the basement of the Tetons, coupled with the results of ongoing research in similar-aged rocks exposed elsewhere in Wyoming, will provide information on how the crust evolved in the early Earth in general and in the Wyoming province in particular. In 1999 the project involved two weeks of fieldwork in Grand Teton National Park and regions to the east, including the Gros Ventre Range, deep canyons of the Buffalo Fork River near Togwotee Pass, and outcrops of basement near Dubois, Wyoming. The main goals of the fieldwork were to complete the sampling of key units in Grand Teton National Park, and to determine whether or not the next nearest outcrops of basement (Gros Ventre, Togwotee Pass and Dubois regions) share the early geologic history preserved in the rocks of Teton National Park. This field work involved four faculty members from UW and a graduate student, who is doing the study as part of her MS thesis. Several months of laboratory analysis at UW have characterized the rocks through thin section, stained slabs, and whole rock geochemical and Nd, Sr, and Ph isotopic methods and produced preliminary U-Pb dates. The principal results from this year 's efforts are that the Teton basement rocks consist of large proportions of juvenile crust, the majority of the rocks formed over a relatively narrow time span from ~2.74 to 2.68 Ga, they were deformed at about 2.67 Ga, and that rocks exposed in the Buffalo Fork River to the east are shallow level equivalents to the deep rocks exposed in the Tetons. Based on these observations and measurements, we hypothesize that the basement rocks of the Tetons formed in an off­shore, island arc setting between 2.74-2.68 Ga, and they were accreted to the Wyoming province at about 2.67 Ga. Post-tectonic intrusion of distinctive peraluminous granites in both the Teton's (Mt. Owens quartz monzonite) and elsewhere in the Wyoming province at 2.55 Ga strengthens our interpretation of a shared history after 2.67 Ga. If this model for the basement rocks in the Teton's holds up, it will be the first case of crustal growth by lateral accretion for the Archean Wyoming province, and one of the earliest examples of plate tectonics style crustal growth documented from anywhere in the world. Plate tectonic growth has dominated the Earth 's evolution from ~2.5 Ga to the present, but it is unclear whether or not analogous processes operated before 2.5 Ga.

The British Caledonides: interpretations from Cenozoic analogues

1984 ◽  
Vol 121 (1) ◽  
pp. 35-46 ◽  
Author(s):  
A. H. G. Mitchell
Keyword(s):  
Northern Ireland ◽  
Foreland Basin ◽  
Accretionary Prism ◽  
Arc Magmatism ◽  
High Angle ◽  
Early Devonian ◽  
Red Sandstone ◽  
Magmatic Arc ◽  
Iapetus Ocean ◽  
Back Arc

AbstractRecent interpretations of Cenozoic arc systems and collision belts facilitate reinterpretation of some aspects of British Caledonide evolution. End-Cambrian ‘Grampian’ collision of the passive ‘Dalradian’ foreland following southeastwards subduction beneath an island arc was accompanied by initiation of the Highland Boundary Fault as a high-angle south-directed oblique-slip thrust. Mid-Ordovician to early Devonian northwestward oblique subduction of the Iapetus Ocean beneath the Grampian orogen resulted in a continental margin magmatic arc, back-arc thrusting and development of an accretionary prism, while southeastward subduction led to arc magmatism and back-arc extension followed by initiation of the Rheic Ocean as a back-arc marginal basin; this syn-subduction N–S asymmetry of the Iapetus Ocean margins was analogous to the E–W asymmetry of the modern Pacific. Closure of Iapetus was diachronous, earlier in the northeast: during end-Silurian collision the southern Caledonides behaved as a passive foreland; post-collision foreland thrusting resulted in deposition and deformation of Lower Old Red Sandstone foreland basin deposits in Wales, and probably in northwest-directed back-thrusting in the region of the Longford-Down accretionary prism. Subsequent dextral movement in the suture zone juxtaposed the southern Caledonides with Scotland and northern Ireland, beneath which northwestward subduction had continued into the early Devonian.

Giant granulite terranes of northeastern Superior Province: the Ashuanipi complex and Minto block

1992 ◽  
Vol 29 (10) ◽  
pp. 2287-2308 ◽  
Author(s):  
J. A. Percival ◽  
J. K. Mortensen ◽  
R. A. Stern ◽  
K. D. Card ◽  
N. J. Bégin
Keyword(s):  
Large Scale ◽  
Accretionary Prism ◽  
Granulite Facies ◽  
Superior Province ◽  
Arc Magmatism ◽  
High Grade ◽  
Block Rotation ◽  
Magmatic Arc ◽  
Metasedimentary Rocks ◽  
Lithological Character

The Ashuanipi complex and Minto block of the Superior Province are large regions that have been classified as "high-grade gneiss" terranes on the basis of the presence of orthopyroxene-bearing units. Like the granite–greenstone and metasedimentary subprovinces of the southern Superior Province, the two terranes consist predominantly of intrusive rocks, but are distinguished by their primary magmatic orthopyroxene. Both "high-grade" and "gneiss" are misnomers because granulite-facies gneisses are only sparingly present and the regions consist dominantly of massive, unmetamorphosed plutonic rock.The Ashuanipi complex consists of a deformed, metamorphosed package of metasedimentary rocks and primitive, early tonalite cut by widespread orthopyroxene ± garnet granodiorite (diatexite), as well as plutons of tonalite, granite, and syenite. Based on its lithological and chronological similarity and on-strike position, the complex appears to be the continuation of metasedimentary subprovinces such as the Quetico. Its evolution involved deposition of immature greywacke in an accretionary prism, early arc (tonalitic) magmatism and deformation, followed by widespread intracrustal magmatism in the period 2700–2670 Ma. Both metamorphic and igneous rocks record equilibration under granulite-facies conditions (700–835 °C; 0.35–0.65 GPa; [Formula: see text] ~0.3) and indicate exposure levels of ~20 km.The Minto block at the latitude of Leaf River consists of several north-northwest-trending domains of similar scale and diversity to the east-trending subprovinces of the southern Superior Province. The central Goudalie domain is dominantly amphibolite-facies tonalitic rocks including some with ages >3 Ga, with small belts of volcanic and sedimentary origin. Lake Minto domain contains poorly preserved supracrustal remnants in a plutonic complex comprising hornblende granodiorite, clinopyroxene ± orthopyroxene granodiorite, orthopyroxene–biotite diatexite, and granite. The hornblende granodiorite suite constitutes most of the Utsalik and Tikkerutuk domains and is thought to represent continental arc magmatism. On the basis of their distinct aeromagnetic and lithological character, two additional domains are evident north of the Leaf River area, the Inukjuak domain in the west and the Douglas Harbour domain in the east.The northerly grain of the Minto block appears to have been established in situ with respect to the easterly belts of the southern Superior Province (i.e., no large-scale block rotation) during the same interval of time (3.0–2.7 Ga). Modification of the tectonic framework for the Superior Province is required to explain Minto arc magmatism. In the interval ~2730–2690 Ma ago, a continental magmatic arc built the Berens River and Bienville subprovinces and Minto block on the southern and eastern edges, respectively, of a northern protocratonic foundation. In the same period, primitive volcanic arcs and accretionary prisms developed outboard on oceanic crust and were accreted to form a southern tectonic regime.

Archean crustal growth by lateral accretion of juvenile supracrustal belts in the south-central Wyoming Province

2006 ◽  
Vol 43 (10) ◽  
pp. 1533-1555 ◽  
Author(s):  
Carol D Frost ◽  
Benjamin L Fruchey ◽  
Kevin R Chamberlain ◽  
B Ronald Frost
Keyword(s):  
Plate Tectonics ◽  
Crustal Growth ◽  
Klamath Mountains ◽  
The South ◽  
Wind River Range ◽  
South Central ◽  
Metavolcanic Rocks ◽  
Wyoming Province ◽  
Terrane Accretion ◽  
Geologic Processes

Neoarchean supracrustal sequences in the south-central Wyoming Province are exposed as relatively small belts in Laramide uplifts. Some sequences are composed of materials derived mainly from pre-existing Wyoming province crust, but others are dominated by juvenile components. The latter include the Miners Delight Formation in the Wind River Range, the Rattlesnake Hills Group in the Granite Mountains, and the Bradley Peak succession in the Seminoe Mountains. U–Pb zircon dates from interbedded metavolcanic rocks suggest that these supracrustal belts are of at least two different ages: ca. 2.67 and ca. 2.72 Ga. We identify a time of contractional deformation and accretion of some of these supracrustal packages to the southern Wyoming Province at ~2.65–2.63 Ga. Magmatism is nearly synchronous with deformation. Some granitoids intrude the Wyoming Province basement, as well as the juvenile rocks thrust onto this basement; these have Nd isotopic compositions indicating that these plutons assimilated some old continental basement during ascent. Plutons intruding the supracrustal rocks located farther from the margin do not show this continental influence. The time scale and geologic processes of deposition, contractional deformation, and plutonism appear analogous to Phanerozoic examples of oceanic terrane accretion, such as formed the Klamath Mountains Province of California and Oregon. We conclude that a major episode of Neoarchean crustal growth involved both the lateral accretion of juvenile terranes and the intrusion of arc magmas formed from mantle-derived and (or) juvenile crustal sources and was driven by geologic processes very similar to modern plate tectonics.

scholarly journals Zircon U–Pb Dating and Lu-Hf Isotope of the Retrograded Eclogite from Chicheng, Northern Hebei Province, China

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xu Kong ◽  
Xueyuan Qi ◽  
Wentian Mi ◽  
Xiaoxin Dong
Keyword(s):  
Regional Metamorphism ◽  
Granulite Facies ◽  
Amphibolite Facies ◽  
Metamorphic Event ◽  
Isotopic Data ◽  
Metamorphic Condition ◽  
Eu Anomaly ◽  
Facies Metamorphism ◽  
Eclogite Facies ◽  
Plagioclase Gneiss

We report zircon U–Pb ages and Lu-Hf isotopic data from two sample of the retrograded eclogite in the Chicheng area. Two groups of the metamorphic zircons from the Chicheng retrograded eclogite were identified: group one shows characteristics of depletion in LREE and flat in HREE curves and exhibit no significant Eu anomaly, and this may imply that they may form under eclogite facies metamorphic condition; group two is rich in HREE and shows slight negative Eu anomaly indicated that they may form under amphibolite facies metamorphic condition. Zircon Lu-Hf isotopic of εHf from the Chicheng eclogite has larger span range from 6.0 to 18.0, which suggests that the magma of the eclogite protolith may be mixed with partial crustal components. The peak eclogite facies metamorphism of Chicheng eclogite may occur at 348.5–344.2 Ma and its retrograde metamorphism of amphibolite fancies may occur at ca. 325.0 Ma. The Hongqiyingzi Complex may experience multistage metamorphic events mainly including Late Archean (2494–2448 Ma), Late Paleoproterozoic (1900–1734 Ma, peak age = 1824.6 Ma), and Phanerozoic (495–234 Ma, peak age = 323.7 Ma). Thus, the metamorphic event (348.5–325 Ma) of the Chicheng eclogite is in accordance with the Phanerozoic metamorphic event of the Hongqiyingzi Complex. The eclogite facies metamorphic age of the eclogite is in accordance with the metamorphism (granulite facies or amphibolite facies) of its surrounding rocks, which implied that the tectonic subduction and exhumation of the retrograded eclogite may cause the regional metamorphism of garnet biotite plagioclase gneiss.

Archean geochronological framework of the Bighorn Mountains, Wyoming

2006 ◽  
Vol 43 (10) ◽  
pp. 1399-1418 ◽  
Author(s):  
Carol D Frost ◽  
C Mark Fanning
Keyword(s):  
Ion Microprobe ◽  
Entire Area ◽  
Wind River Range ◽  
Gneiss Complex ◽  
Granitic Intrusion ◽  
Northern Portion ◽  
Tonalitic Gneiss ◽  
Archean Crust ◽  
Wyoming Province ◽  
Bighorn Mountains

The Bighorn Mountains of the central Wyoming Province expose a large tract of Archean crust that has been tectonically inactive and at relatively high crustal levels since ~2.7 Ga. Seven sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon and titanite age determinations on samples of the main lithologic units provide a geochronological framework for the evolution of this area. The oldest, precisely dated magmatic event occurred at 2950 ± 5 Ma, when diorite to granite dykes and sills intruded an older gneiss complex exposed in the central and southern Bighorn Mountains. Rocks as old as 3.25 Ga may be present in this gneissic basement, as indicated by the oldest dates obtained on areas of zircon grains that are interpreted as inherited cores. A tonalitic gneiss was intruded into the gneiss complex at 2886 ± 5 Ma. Deformation of the central and southern gneisses preceded the intrusion of the Bighorn batholith, a tonalitic to granitic intrusion that occupies the northern portion of the uplift. This composite batholith was intruded over the period 2.86–2.84 Ga. Ca. 3.0–2.8 Ga crust is also present in the Beartooth Mountains, the Washakie block of the northeastern Wind River Range, the Owl Creek Mountains, and the northern Granite Mountains, but late Archean deformation and plutonism has obscured much of the earlier history in the southern portion of this area. The entire area, referred to as the Beartooth–Bighorn Magmatic Zone, has been undeformed since 2.6 Ga. Proterozoic extension was focused in those parts of the Wyoming Province outside of this domain.

scholarly journals Geological archive of the onset of plate tectonics

2018 ◽  
Vol 376 (2132) ◽  
pp. 20170405 ◽  
Author(s):  
Peter A. Cawood ◽  
Chris J. Hawkesworth ◽  
Sergei A. Pisarevsky ◽  
Bruno Dhuime ◽  
Fabio A. Capitanio ◽  
...  
Keyword(s):  
Plate Tectonics ◽  
Foreland Basin ◽  
Sea Floor ◽  
Palaeomagnetic Data ◽  
Peraluminous Granites ◽  
Lithospheric Plates ◽  
Crustal Reworking ◽  
Sea Floor Spreading ◽  
Back Arc ◽  
Earth Dynamics

Plate tectonics, involving a globally linked system of lateral motion of rigid surface plates, is a characteristic feature of our planet, but estimates of how long it has been the modus operandi of lithospheric formation and interactions range from the Hadean to the Neoproterozoic. In this paper, we review sedimentary, igneous and metamorphic proxies along with palaeomagnetic data to infer both the development of rigid lithospheric plates and their independent relative motion, and conclude that significant changes in Earth behaviour occurred in the mid- to late Archaean, between 3.2 Ga and 2.5 Ga. These data include: sedimentary rock associations inferred to have accumulated in passive continental margin settings, marking the onset of sea-floor spreading; the oldest foreland basin deposits associated with lithospheric convergence; a change from thin, new continental crust of mafic composition to thicker crust of intermediate composition, increased crustal reworking and the emplacement of potassic and peraluminous granites, indicating stabilization of the lithosphere; replacement of dome and keel structures in granite-greenstone terranes, which relate to vertical tectonics, by linear thrust imbricated belts; the commencement of temporally paired systems of intermediate and high dT/dP gradients, with the former interpreted to represent subduction to collisional settings and the latter representing possible hinterland back-arc settings or ocean plateau environments. Palaeomagnetic data from the Kaapvaal and Pilbara cratons for the interval 2780–2710 Ma and from the Superior, Kaapvaal and Kola-Karelia cratons for 2700–2440 Ma suggest significant relative movements. We consider these changes in the behaviour and character of the lithosphere to be consistent with a gestational transition from a non-plate tectonic mode, arguably with localized subduction, to the onset of sustained plate tectonics. This article is part of a discussion meeting issue ‘Earth dynamics and the development of plate tectonics'.

Plume-induced subduction and plate fracturation, deep mantle overturn, and the onset of plate tectonics.

2021 ◽  
Author(s):  
Anne Davaille
Keyword(s):  
Plate Tectonics ◽  
Colloidal Dispersions ◽  
Small Scale ◽  
Dense Layer ◽  
Mantle Dynamics ◽  
Simultaneous Generation ◽  
Tensile Fractures ◽  
Back Arc ◽  
The Impact ◽  
Surface Plate

<p>Mantle dynamics can now be recovered in the laboratory, when aqueous colloidal dispersions are dryed from above, and either insulated or heated from below. As their rheology varies from viscous to visco-elasto-plastic to brittle when drying proceeds, a skin (i.e. an experimental lithosphere) develops at the surface. Submitted to buckling, small-scale convection, or an impinging hot plume, this skin can break and one-sided subduction is then observed to proceed. In the case of plume-induced subduction (PIS), the impact of the plume under the skin induces tensile fractures, plume material upwelling through them and spreading at the surface, analogous to volcanic flooding, leading to skin bending and eventually one-sided subduction along arcuate segments which retreat away from the plume. A system of accreting ridges can develop inside the back-arc basin. If PIS develops isolated in an overall stagnant lithosphere, subduction eventually either stops as the result of subducted plate necking, or when plume spreading stops. On the other hand, if the lithosphere contains other heterogeneities (damage) such as faults, accretion ridges or another PIS event, the weight of the subducting plate can induce faraway plate breaking and horizontal mobilization of the surface plate.</p><p>As the lithosphere has to accumulate damage to fracture, it takes time from the first subduction event to the organization of a network of subducting and accreting plates. But the presence of several hot plumes simultaneously accelerates the establishment of an organized pattern of plates, subduction and accretion. And when we run experiments where the mantle contains initially a denser layer at the bottom, the global overturn of this dense layer results in the simultaneous generation of plumes over the whole mantle surface, which produces a burst of PIS events and the quick establishment of a plate tectonic-like regime. <br>Such a global overturn has been proposed to explain the big peak in continental crust growth 2.7 Ga on Earth. Our experiments suggest that it could also have triggered the formation of the plates boundaries and flow organization necessary to plate tectonics.</p>

Geochemistry and tectonic environment of the Şarkışla area volcanic rocks in central Anatolia, Turkey

1987 ◽  
Vol 51 (362) ◽  
pp. 553-559 ◽  
Author(s):  
E. Gökten ◽  
P. A. Floyd
Keyword(s):  
Upper Cretaceous ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Central Anatolia ◽  
Magmatic Arc ◽  
Early Tertiary ◽  
Tectonic Environment ◽  
Geochemical Study ◽  
Lithological Composition ◽  
Back Arc

AbstractThe volcanic rocks of the Şarkışla area in northeastern central Anatolia are associated with volcaniclastics, turbiditic limestones and pelagic-hemipelagic shales of Upper Cretaceous-Palaeocene age. A preliminary geochemical study was undertaken to constrain local tectonic models, and due to the variable altered nature of the volcanics, determine the lithological composition and magma type. Chemically the volcanics are an andesite-dominated suite of calc-alkali lavas, probably developed adjacent to an active continental margin in a local (ensialic back-arc?) basinal area. The volcanic activity was probably related to a postulated magmatic arc just south of the area during the early Tertiary.

scholarly journals Evolution of the early Mesozoic Cordilleran arc: The detrital zircon record of back-arc basin deposits, Triassic Buckskin Formation, western Arizona and southeastern California, USA

Geosphere ◽  
2020 ◽  
Vol 16 (4) ◽  
pp. 1042-1057
Author(s):  
N.R. Riggs ◽  
T.B. Sanchez ◽  
S.J. Reynolds
Keyword(s):  
North America ◽  
Detrital Zircon ◽  
Colorado Plateau ◽  
Depositional Environments ◽  
Coarse Grained ◽  
Land Bridge ◽  
Magmatic Arc ◽  
Early Mesozoic ◽  
Northern Nevada ◽  
Back Arc

Abstract A shift in the depositional systems and tectonic regime along the western margin of Laurentia marked the end of the Paleozoic Era. The record of this transition and the inception and tectonic development of the Permo-Triassic Cordilleran magmatic arc is preserved in plutonic rocks in southwestern North America, in successions in the distal back-arc region on the Colorado Plateau, and in the more proximal back-arc region in the rocks of the Buckskin Formation of southeastern California and west-central Arizona (southwestern North America). The Buckskin Formation is correlated to the Lower–Middle Triassic Moenkopi and Upper Triassic Chinle Formations of the Colorado Plateau based on stratigraphic facies and position and new detrital zircon data. Calcareous, fine- to medium-grained and locally gypsiferous quartzites (quartz siltstone) of the lower and quartzite members of the Buckskin Formation were deposited in a marginal-marine environment between ca. 250 and 245 Ma, based on detrital zircon U-Pb data analysis, matching a detrital-zircon maximum depositional age of 250 Ma from the Holbrook Member of the Moenkopi Formation. An unconformity that separates the quartzite and phyllite members is inferred to be the Tr-3 unconformity that is documented across the Colorado Plateau, and marks a transition in depositional environments. Rocks of the phyllite and upper members were deposited in wholly continental depositional environments beginning at ca. 220 Ma. Lenticular bodies of pebble to cobble (meta) conglomerate and medium- to coarse-grained phyllite (subfeldspathic or quartz wacke) in the phyllite member indicate deposition in fluvial systems, whereas the fine- to medium-grained beds of quartzite (quartz arenite) in the upper member indicate deposition in fluvial and shallow-lacustrine environments. The lower and phyllite members show very strong age and Th/U overlap with grains derived from Cordilleran arc plutons. A normalized-distribution plot of Triassic ages across southwestern North America shows peak magmatism at ca. 260–250 Ma and 230–210 Ma, with relatively less activity at ca. 240 Ma, when a land bridge between the arc and the continent was established. Ages and facies of the Buckskin Formation provide insight into the tectono-magmatic evolution of early Mesozoic southwestern North America. During deposition of the lower and quartzite members, the Cordilleran arc was offshore and likely dominantly marine. Sedimentation patterns were most strongly influenced by the Sonoma orogeny in northern Nevada and Utah (USA). The Tr-3 unconformity corresponds to both a lull in magmatism and the “shoaling” of the arc. The phyllite and upper members were deposited in a sedimentary system that was still influenced by a strong contribution of detritus from headwaters far to the southeast, but more locally by a developing arc that had a far stronger effect on sedimentation than the initial phases of magmatism during deposition of the basal members.

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