U–Pb and Hf isotopic data from Franklinian Basin strata: insights into the nature of Crockerland and the timing of accretion, Canadian Arctic Islands

2012 ◽  
Vol 49 (11) ◽  
pp. 1316-1328 ◽  
Author(s):  
Owen A. Anfinson ◽  
Andrew L. Leier ◽  
Rich Gaschnig ◽  
Ashton F. Embry ◽  
Keith Dewing
Keyword(s):  
Detrital Zircon ◽  
Middle Devonian ◽  
Canadian Arctic ◽  
Foreland Basin ◽  
Late Devonian ◽  
Isotopic Data ◽  
Zircon Population ◽  
East Greenland ◽  
Two Samples ◽  
Laurentian Margin

New detrital zircon uranium–lead (U–Pb) ages and initial epsilon hafnium (εHf(i)) data from the Devonian clastic succession of the Canadian Arctic Islands refines the provenance of strata within the Franklinian Basin and provides constraints on the geologic evolution of the landmass responsible for the Ellesmerian Orogen. This study contributes more than 500 U–Pb ages and 32 εHf(i) values from the Blackley Formation and the Parry Islands Formation. The Middle Devonian Blackley Formation represents the onset of clastic sedimentation into the Franklinian Basin during the Devonian period. Detrital zircon from two samples yield U–Pb age populations of 380–470, 500–700, 900–2100, and 2550–3000 Ma. The population of 500–700 Ma U–Pb ages indicates a source exotic to the northern Laurentian margin and is attributed to a continental landmass located north of the present Canadian Arctic Islands (often referred to as Crockerland). This is some of the earliest evidence of 500–700 Ma detrital zircon deposition onto the northern Laurentian margin and indicates this northern landmass is at least partially accreted to Laurentia by early-Eifelian time. The Late Devonian Parry Islands Formation is the uppermost succession of Ellesmerian Orogen foreland basin sedimentation in the Franklinian Basin. Detrital zircon from four samples yield U–Pb age populations of 370–450, 470–750, 930–2100, and 2300–3200 Ma. The U–Pb ages suggest the Parry Islands Formation is derived from the northern source terrane (Crockerland) and indicate this landmass contains rocks similar to that of the east Greenland Caledonides, Pearya, and northeastern Baltica. Rim and core U–Pb double dates from the 500–700 Ma detrital zircon population and εHf(i) values from the 380–450, 520–550, and 650–710 Ma detrital zircon populations help constrain magma generation processes within Crockerland and suggest the zircons are derived from a juvenile lithosphere.

Detrital zircon populations of the eastern Laurentian margin in the Appalachians

Geology ◽  
2020 ◽  
Author(s):  
Yvette D. Kuiper ◽  
Christopher Hepburn
Keyword(s):  
United States ◽  
Detrital Zircon ◽  
Orogenic Belt ◽  
Grenville Province ◽  
Zircon Age ◽  
Zircon Population ◽  
Middle Ordovician ◽  
Archean Crust ◽  
Laurentian Margin

Newly compiled U-Pb detrital zircon data from eight geographic domains along the eastern Laurentian margin from Newfoundland (Canada) to Alabama (United States) show a highly consistent signature along strike, with only minor local variations. The Precambrian signature is characterized by a small ca. 2.7 Ga population and a major ca. 1.9–0.9 Ga population that peaks at ca. 1.2–1.0 Ga. Detrital zircon populations are from Laurentian Archean crust (ca. 2.7 Ga population), Paleoproterozoic orogens (ca. 1.9–1.6 Ga), the Granite-Rhyolite Province (ca. 1.5–1.4 Ga), and the Elzevir terrane and Grenville Province (ca. 1.3–0.9 Ga). The Mesoproterozoic populations vary in size depending on proximity to the ca. 1.5–1.4 Ga Granite-Rhyolite Province, the ca. 1245–1225 Ma Elzevir terrane, and the ca. 1.2–0.9 Ga Grenville Province. A middle Ordovician zircon population varies in size along strike depending on input from the Taconic orogenic belt, but it is strongest in the northern Appalachians. Because of the general along-strike consistency in detrital zircon age populations, the compilation of all 7534 concordant U-Pb detrital zircon data can be used in future U-Pb detrital zircon studies as an indicator for eastern Laurentian margin sources.

Evidence for Neoproterozoic orogenesis and early high temperature Scandian deformation events in the southern East Greenland Caledonides

2003 ◽  
Vol 140 (3) ◽  
pp. 309-333 ◽  
Author(s):  
A. G. LESLIE ◽  
A. P. NUTMAN
Keyword(s):  
High Temperature ◽  
Shear Zones ◽  
Granulite Facies ◽  
East Greenland ◽  
Metasedimentary Rocks ◽  
Two Samples ◽  
High Grade Metamorphism ◽  
Granitoid Emplacement ◽  
Laurentian Margin ◽  
Granitoid Intrusions

Integrated field structural studies and SHRIMP U–Pb zircon and monazite dating have been undertaken in Renland, west of Scoresby Sund district in the southern part of the East Greenland Caledonides. Southwest Renland is dominated by metasedimentary rocks correlated with the Krummedal supracrustal succession of East Greenland and which on Renland were intruded by augen granites. Krummedal psammite from Renland yielded a spectrum of Mesoproterozoic to Palaeoproterozoic detrital U–Pb zircon dates, the youngest of which indicate deposition of the psammite occurred c. 1000 Ma ago, thus post-dating Grenvillian continent–continent collision in North American Laurentia. These Krummedal metasediments were deformed into regional nappe-scale folds prior to metamorphism, crustal anatexis and genesis of augen granites; an example of the latter has been dated at 915±18 Ma (U–Pb zircon). This demonstrates early Neoproterozoic high-temperature tectono-metamorphism affecting rocks within the southern East Greenland Caledonides, broadly contemporaneous with similar rocks farther north in East Greenland and with Sveconorwegian events on Baltica. Still in southwestern Renland, a later thermal event led to development of uppermost amphibolite to granulite facies metamorphic assemblages, veins and patches of in situ garnetiferous melt-bearing neosome in both metasediments (432±6 Ma, U–Pb zircon) and in the augen granites, and contemporaneous biotite-bearing granite sheets in top-down-to-the-E extensional shear zones (434±5 Ma, U–Pb zircon). Monazites from southwestern Renland record Caledonian thermal events as late as 410−400 Ma. In contrast, southeastern Renland is dominated by quartzofeldspathic migmatites with a strongly Caledonian signature but enclosing relicts of augen granite and retrogressed granulite facies psammitic and pelitic metasediment. There is also a sequence of Caledonian granitoid intrusions. Two samples from a hypersthene monzonite intrusion yielded U–Pb zircon dates of 424±8 Ma and 424±6 Ma. This pluton shows the marginal effects of the regional migmatization and was intruded early in the sequence of granitoid emplacement. An amphibolite facies migmatite, textural evidence from which suggests that it had never hosted granulite facies assemblages, records zircon growth at 423±6 Ma, and closure of monazite by 402±10 Ma. High grade metamorphism, and the protracted sequence of granitoid emplacement and still younger thermal events which together span the period between 430 and 400 Ma may, in part, reflect complicated lithospheric dynamics associated with subduction outboard of the Laurentian margin. Crustal segments carrying the relict evidence of Neoproterozoic and early Caledonian events must then quickly have been thrust northwestwards in foreland-propagating, northwesterly directed thrusts over Cambro-Ordovician platformal sequences on the Laurentian margin. This records the final closure of Iapetus, encroachment of Baltica and continent–continent collision from late Llandovery times (425–430 Ma).

scholarly journals O GRUPO IBIÁ (FAIXA BRASÍLIA MERIDIONAL): EVIDÊNCIAS ISOTÓPICAS SM-ND E U-PB DE BACIA COLISIONAL TIPO FLYSCH

2013 ◽  
Author(s):  
Paulo Henrique Amorim Dias ◽  
Carlos Mauricio Noce ◽  
Antônio Carlos Pedrosa-Soares ◽  
Hildor José Seer ◽  
Ivo Antônio Dussin ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Mineralogical Composition ◽  
Isotopic Data ◽  
Volcanic Origin ◽  
Zircon Population

O Grupo Ibiá inclui as formações Cubatão e Rio Verde. A primeira, composta por metaconglomerado suportado pela matriz, com intercalações de metapelito e quartzito, ocorre em lentes esparsas sobre discordância erosiva no topo do Grupo Canastra. Datações U-Pb em grãos detríticos de zircão deste conglomerado indicam idade máxima de sedimentação em ca. 1190 Ma, e mostram o mesmo amplo espectro de valores dados pelo Grupo Canastra. A Formação Rio Verde, composta de clorita-muscovita xisto com lentes de quartzito, repousa sobre as unidades antes referidas. Grãos de zircão do xisto Rio Verde fornecem idades dominantemente menores que 1000 Ma, com a média da moda dos menores valores em ca. 639 Ma. Esta população de zircão consiste de grãos mal arredondados a euédricos. Os dados analíticos, incluindo Sm-Nd (Nd(640 Ma) de -0,1 a 0,5 Ma e idades-modelo em 1,2 Ga) e a composição mineralógica do xisto Rio Verde sugerem protólitos provenientes de fontes ricas em rochas ígneas intermediárias a máficas, tais como arcos magmáticos e ofiolitos. Em conclusão, o Grupo Ibiá representaria bacia colisional (flysch), relacionada a frentes de empurrão da Faixa Brasília Meridional.Palavras-chave: geocronologia U-Pb, bacia orogênica, Grupo Ibiá, Faixa BrasíliaABSTRACT: THE IBIÁ GROUP (SOUTHERN BRASÍLIA BELT): ISOTOPIC SM-ND AND U-PB EVIDENCE FOR A COLLISIONAL FLYSCH-TYPE BASIN. The Ibiá Group includes the Cubatão and Rio Verde formations. The first consists of matrix-supported metaconglomerate with intercalations of metapelite and quartzite, occurring in sparse lenses on the top of the Canastra Group. U-Pb ages of detrital zircon grains from the Cubatão conglomerate and Canastra quartzite show similar wide age spectra and youngest values around 1190 Ma. The Rio Verde Formation, consisting of chlorite-muscovite schist and quartzite lenses, overlies the Cubatão Formation and Canastra Group. U-Pb data from zircon grains of the Rio Verde schist show a great dominance of ages younger than 1000 Ma, with a mean age of the youngest values around 639 Ma. The younger zircon population shows poorly rounded to euhedral zircon crystals, some of them of volcanic origin. Lithochemical data, including Sm-Nd isotopic data (Nd(640 Ma) from -0.1 to 0.5 and Tdm model ages around 1.2 Ga), together with the mineralogical composition suggest provenance from intermediate to mafic igneous sources for the Rio Verde sediments. In conclusion, the Ibiá Group is related to a collisional (flysch) basin associated with thrust fronts along the Southern Brasília Belt.Keywords: U-Pb geochronology, orogenic basin, flysch, Ibiá Group, Brasília Belt

Zircon provenance of the Carboniferous Mattson delta complex, western Laurentian margin, Canada: record of a Greenland-sourced pancontinental river system

2018 ◽  
Vol 55 (10) ◽  
pp. 1129-1138 ◽  
Author(s):  
Margot McMechan ◽  
Lisel Currie ◽  
Barry Richards ◽  
Filippo Ferri ◽  
William Matthews ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Source Area ◽  
River System ◽  
Lower Permian ◽  
Small Contribution ◽  
Complex Samples ◽  
Western Margin ◽  
Middle Mississippian ◽  
Two Samples ◽  
Laurentian Margin

New detrital zircon U–Pb dates for seven late Viséan to Bashkirian (Middle Mississippian to Lower Pennsylvanian) Mattson and Kindle formation sandstone samples from the Mattson delta complex in the Liard Basin of northeastern British Columbia, combined with two previously published detrital zircon samples from these units, indicate a dominant Greenland Caledonian clastic wedge and orogen source with a small contribution of Ellesmerian-aged material. This provenance remained consistent over time. The Labrador–Greenland high was the only paleogeographically viable source area during the time of deposition of the Mattson delta complex. Detritus deposited on the western margin of Laurentia in the Mattson delta complex was likely transported southwestward by a late Viséan to Bashkirian pancontinental river system. This conclusion contrasts with previous interpretations which proposed that these sediments were recycled from the Ellesmerian clastic wedge. Tectonic uplift and denudation of eastern Greenland provided detritus from the Silurian to Devonian Caledonian clastic wedge and orogen to the western margin of Laurentia and detritus from the Caledonian orogen to the Serpukhovian to middle Bashkirian (Namurian) conglomeratic successions of the Millstone Grits in England. Detrital zircon U–Pb dates for two samples from the unconformably overlying Cisuralian (lower Permian) Tika formation are similar to those of the Mattson delta complex samples, as are those from the Pennsylvanian Spray Lakes Group of the southern Prophet Trough, indicating they all probably shared the same dominant source areas. The Tika formation was mainly derived from recycling of the Mattson and other Caledonide-sourced sediments of northern Laurentia.

scholarly journals Hidden Middle Devonian Magmatism of North-Eastern Siberia: Age Constraints from Detrital Zircon U–Pb Data

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 874
Author(s):  
Victoria B. Ershova ◽  
Andrei V. Prokopiev ◽  
Andrei K. Khudoley
Keyword(s):  
Detrital Zircon ◽  
Middle Devonian ◽  
Passive Margin ◽  
Large Igneous Province ◽  
Late Devonian ◽  
Eastern Siberia ◽  
Provenance Analysis ◽  
Fold And Thrust Belt ◽  
North Eastern ◽  
Middle Paleozoic

We present new data on the tectonic evolution of north-eastern Siberia using an integrated provenance analysis based on U–Pb detrital zircon dating and sandstone petrography of Devonian sedimentary strata. Our petrographic data suggest that Upper Devonian sandstones of north-eastern Siberia were derived from a local provenance, supported by the widespread distribution of ca. 1900–2000 Ma magmatic events in the basement of the neighboring Ust’-Lena and Olenek uplifts. Devonian detrital zircon age distributions of the Devonian sandstones are similar to ages of Middle Paleozoic magmatic rocks of Yakutsk-Vilyui large igneous province (LIP). Therefore, we suggest that the studied sandstones were derived from proximally-located uplifted blocks composed of Proterozoic–Devonian rocks and Middle–Late Devonian volcanics. Moreover, the abundance of Middle–Late Devonian zircons is suggestive of a wider distribution of coeval magmatism across north-eastern Siberia than previously supposed. We propose that widespread Devonian magmatism associated with the Yakutsk-Vilyui LIP also occurred to the east of our study area and is now buried beneath thick Carboniferous–Jurassic sedimentary rocks of the eastern Siberian passive margin, subsequently deformed into the Late Jurassic–Cretaceous Verkhoyansk fold-and-thrust belt. We also propose that the major pulse of the Yakutsk-Vilyui LIP occurred in north-eastern Siberia during the Middle Devonian at ca. 390 Ma, some 15 million years earlier than within the Vilyui rift basin in eastern Siberia (ca. 375 Ma).

scholarly journals Nature and timing of Late Devonian–early Mississippian island-arc magmatism in the Northern Sierra terrane and implications for regional Paleozoic plate tectonics

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 258-280
Author(s):  
Vladislav Powerman ◽  
Richard Hanson ◽  
Anna Nosova ◽  
Gary H. Girty ◽  
Jeremy Hourigan ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Plate Tectonics ◽  
Detrital Zircons ◽  
Island Arc ◽  
Passive Margin ◽  
Late Devonian ◽  
Arc Magmatism ◽  
Accretionary Complex ◽  
Field Evidence ◽  
Laurentian Margin

Abstract The Northern Sierra terrane is one of a series of Paleozoic terranes outboard of the western Laurentian margin that contain lithotectonic elements generally considered to have originated in settings far removed from their present relative locations. The Lower to Middle Paleozoic Shoo Fly Complex makes up the oldest rocks in the terrane and consists partly of thrust-imbricated deep-marine sedimentary strata having detrital zircon age signatures consistent with derivation from the northwestern Laurentian margin. The thrust package is structurally overlain by the Sierra City mélange, which formed within a mid-Paleozoic subduction zone and contains tectonic blocks of Ediacaran tonalite and sandstone with Proterozoic to early Paleozoic detrital zircon populations having age spectra pointing to a non–western Laurentian source. Island-arc volcanic rocks of the Upper Devonian Sierra Buttes Formation unconformably overlie the Shoo Fly Complex and are spatially associated with the Bowman Lake batholith, Wolf Creek granite stock, and smaller hypabyssal felsic bodies that intrude the Shoo Fly Complex. Here, we report new results from U-Pb sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) dating of 15 samples of the volcanic and intrusive rocks, along with geochemical studies of the dated units. In addition, we report U-Pb laser ablation–inductively coupled plasma–mass spectrometry ages for 50 detrital zircons from a feldspathic sandstone block in the Sierra City mélange, which yielded abundant Ordovician to Early Devonian (ca. 480–390 Ma) ages. Ten samples from the composite Bowman Lake batholith, which cuts some of the main thrusts in the Shoo Fly Complex, yielded an age range of 371 ± 9 Ma to 353 ± 3 Ma; felsic tuff in the Sierra Buttes Formation yielded an age of 363 ± 7 Ma; and three felsic hypabyssal bodies intruded into the Sierra City mélange yielded ages of 369 ± 4 Ma to 358 ± 3 Ma. These data provide a younger age limit for assembly of the Shoo Fly Complex and indicate that arc magmatism in the Northern Sierra terrane began with a major pulse of Late Devonian (Famennian) igneous activity. The Wolf Creek stock yielded an age of 352 ± 3 Ma, showing that the felsic magmatism extended into the early Mississippian. All of these rocks have similar geochemical features with arc-type trace-element signatures, consistent with the interpretation that they constitute a petrogenetically linked volcano-plutonic system. Field evidence shows that the felsic hypabyssal intrusions in the Sierra City mélange were intruded while parts of it were still unlithified, indicating that a relatively narrow time span separated subduction-related deformation in the Shoo Fly Complex and onset of Late Devonian arc magmatism. Following recent models for Paleozoic terrane assembly in the western Cordillera, we infer that the Shoo Fly Complex together with strata in the Roberts Mountains allochthon in Nevada migrated south along a sinistral transform boundary prior to the onset of arc magmatism in the Northern Sierra terrane. We suggest that the Shoo Fly Complex arrived close to the western Laurentian margin at the same time as the Roberts Mountains allochthon was thrust over the passive margin during the Late Devonian–early Mississippian Antler orogeny. This led to a change in plate kinematics that caused development of a west-facing Late Devonian island arc on the Shoo Fly Complex. Due to slab rollback, the arc front migrated onto parts of the Sierra City mélange that had only recently been incorporated into the accretionary complex. In the mélange, blocks of Ediacaran tonalite, as well as sandstones having detrital zircon populations with non–western Laurentian sources, may have been derived from the Yreka and Trinity terranes in the eastern Klamath Mountains, where similar rock types occur. If so, this suggests that these Klamath terranes were in close proximity to the developing accretionary complex in the Northern Sierra terrane in the Late Devonian.

scholarly journals Depositional constraints from detrital zircon geochronology of strata from multiple lithotectonic belts in south-central Maine, USA

2019 ◽  
pp. 093-136
Author(s):  
Samuel F.A. Cartwright ◽  
David P. West, Jr. ◽  
William H. Amidon
Keyword(s):  
Detrital Zircon ◽  
Tectonic Setting ◽  
Sediment Source ◽  
Zircon Geochronology ◽  
Detrital Zircon Geochronology ◽  
South Central ◽  
Two Samples ◽  
Sediment Input ◽  
Laurentian Margin ◽  
Extensional Setting

The bedrock geology of south-central Maine is characterized by a series of fault-bounded lithotectonic terranes that were accreted onto the Laurentian margin during Silurian-Devonian orogenesis.  The multiple phases of deformation and metamorphism associated with this tectonism obscured most primary features in the protolith rocks, leading to uncertainties in their pre-accretionary history. Here we present the results of detrital zircon geochronology from five of these terranes and make interpretations on their depositional ages, sediment provenance, and tectonic setting of deposition.Detrital zircon from Silurian rocks of the Vassalboro Group in the eastern-most portion of the Central Maine basin indicate sediment input in an extensional setting from both Laurentian and Ordovician sources.  Results from Ordovician rocks of the Casco Bay Group of the Liberty-Orrington belt support earlier findings that these rocks have strong peri-Gondwanan affinities.  Detrital zircon from the Appleton Ridge Formation and Ghent phyllite of the Fredericton trough are consistent with a peri-Gondwanan sediment source with no evidence of Laurentian sediment input.  These findings are consistent with that of Dokken et al. (2018) for older Fredericton trough strata (i.e., Digdeguash Formation) east of the Fredericton fault in southern New Brunswick.  Two samples from the Jam Brook complex reveal extreme differences in depositional age (Ordovician vs. Mesoproterozoic) and tectonic affinity and support the hypothesis that this narrow belt represents a fault complex containing a wide variety of stratigraphic units.  Detrital zircon from Ordovician rocks of the Benner Hill Sequence indicate a peri-Gondwanan sediment source with no Laurentian input.Collectively, the pre-Silurian rocks of the Liberty-Orrington belt, Jam Brook complex, Benner Hill Sequence, and Late Ordovician-Early Silurian strata from the Appleton Ridge and Ghent phyllite in the Fredericton trough show peri-Gondwanan affinities with no evidence of Laurentian sediment input.  This suggests a barrier exisited between the Laurentian margin and these peri-Gondwanan terranes prior to about 435 Ma.  In contrast, Silurian strata from the eastern portion of the Central Maine basin do show evidence of a Laurentian sediment source, along with deposition in an extensional setting (lacking in all other samples), thus signaling a fundamental change in tectonic regime.

Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides

2000 ◽  
pp. 42-49 ◽  
Author(s):  
A. Graham Leslie ◽  
Allen P. Nutman
Keyword(s):  
Thermal Activity ◽  
Isotopic Data ◽  
Zircon Age ◽  
East Greenland ◽  
Original Series ◽  
Age Determinations

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Leslie, A. G., & Nutman, A. P. (2000). Episodic tectono-thermal activity in the southern part of the East Greenland Caledonides. Geology of Greenland Survey Bulletin, 186, 42-49. https://doi.org/10.34194/ggub.v186.5214 _______________ Isotopic data from the Renland augen granites of the Scoresby Sund region (Figs 1, 2) provided some of the first convincing support for relicts of potentially Grenvillian tectono-thermal activity within the East Greenland Caledonides. In Renland, Chadwick (1975) showed the presence of major bodies of augen granite (Fig. 2) interpreted by Steiger et al. (1979), on the basis of Rb–Sr whole rock and U–Pb zircon age determinations, to have been emplaced about 1000 Ma ago.

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