Depositional timing of Neoarchean turbidites of the Slave craton—recommended nomenclature and type localities

Two temporally distinct Neoarchean turbidite packages are known to occur in the Slave craton. The older is a greywacke–mudstone succession that includes the renowned Burwash Formation (ca. 2661 Ma). In this study, a previously undated tuff bed is demonstrated to have crystallized at ca. 2650.5 ± 1.0 Ma refining the deposition age of these turbidites between ca. 2661 and 2650 Ma. The younger turbidites are locally distinctive as they contain interstratified banded iron formation (BIF). Previous work demonstrated that the younger turbidites were deposited between ca. 2640 and 2615 Ma, based entirely on maximum depositional ages from detrital zircons. A ∼3 cm thick felsic to intermediate tuff bed was discovered interbedded with these BIF-bearing turbidites. The tuff bed contains a single age population of zircon with a crystallization age of 2620 ± 6 Ma defining the depositional timing of these BIF-bearing turbidites. New U–Pb detrital zircon dates from extensive turbidite sequences in the eastern and central part of the Slave craton are also presented. We use the new and previously published results to recommend nomenclature for these extensive sedimentary rocks in the Slave craton. The ca. 2661–2650 Ma turbidites remain part of the previously ascribed Duncan Lake Group. The younger ca. 2620 Ma turbidites are assigned to the new Slemon Group. Where robust age-data exist, we recommend formation names and include type localities for each.

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Enigmatic provenance signature of sandstone from the Okwa Group, Botswana

South African Journal of Geology ◽

10.25131/sajg.123.0022 ◽

2020 ◽

Vol 123 (3) ◽

pp. 331-342

Author(s):

T. Andersen ◽

M.A. Elburg ◽

J. Lehmann

Keyword(s):

South Africa ◽

Detrital Zircon ◽

Sedimentary Rock ◽

Age Distribution ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

Significant Shift ◽

Zircon Age ◽

Three Samples ◽

Isotope Distributions

Abstract Detrital zircon grains from three samples of sandstone from the Tswaane Formation of the Okwa Group of Botswana have been dated by U-Pb and analysed for Hf isotopes by multicollector LA-ICPMS. The detrital zircon age distribution pattern of the detrital zircons is dominated by a mid-Palaeoproterozoic age fraction (2 000 to 2 150 Ma) with minor late Archaean – early Palaeoproterozoic fractions. The 2 000 to 2 150 Ma zircon grains show a range of epsilon Hf from -12 to 0. The observed age and Hf isotope distributions overlap closely with those of sandstones of the Palaeoproterozoic Waterberg Group and Keis Supergroup of South Africa, but are very different from Neoproterozoic deposits in the region, and from the Takatswaane siltstone of the Okwa Group, all of which are dominated by detrital zircon grains younger than 1 950 Ma. The detrital zircon data indicate that the sources of Tswaane Formation sandstones were either Palaeoproterozoic rocks in the basement of the Kaapvaal Craton, or recycled Palaeoproterozoic sedimentary rocks similar to the Waterberg, Elim or Olifantshoek groups of South Africa. This implies a significant shift in provenance regime between the deposition of the Takatswaane and Tswaane formations. However, the detrital zircon data are also compatible with a completely different scenario in which the Tswaane Formation consists of Palaeoproterozoic sedimentary rock in tectonic rather than depositional contact with the other units of the Okwa Group.

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Detrital Zircon U-Pb-Hf Isotopes of Middle Neoproterozoic Sedimentary Rocks in the Altyn Tagh Orogen, Southeastern Tarim: Insights for a Tarim-South China-North India Connection in the Periphery of Rodinia

Lithosphere ◽

10.2113/2020/8895888 ◽

2020 ◽

Vol 2020 (1) ◽

pp. 1-10

Author(s):

Qian Liu ◽

Guochun Zhao ◽

Jianhua Li ◽

Jinlong Yao ◽

Yigui Han ◽

...

Keyword(s):

South China ◽

Detrital Zircon ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

North India ◽

Hf Isotopes ◽

Altyn Tagh ◽

Tarim Craton ◽

Rodinia Supercontinent ◽

New Perspective

Abstract The location of the Tarim craton during the assembly and breakup of the Rodinia supercontinent remains enigmatic, with some models advocating a Tarim-Australia connection and others a location at the heart of the unified Rodinia supercontinent between Australia and Laurentia. In this study, our new zircon U-Pb dating results suggest that middle Neoproterozoic sedimentary rocks in the Altyn Tagh orogen of the southeastern Tarim craton were deposited between ca. 880 and 760 Ma in a rifting-related setting slightly prior to the breakup of Rodinia at ca. 750 Ma. A compilation of existing Neoproterozoic geological records also indicates that the Altyn Tagh orogen of the southeastern Tarim craton underwent collision at ca. 1.0-0.9 Ga and rifting at ca. 850-600 Ma related to the assembly and breakup of Rodinia. Furthermore, in order to establish the paleoposition of the Tarim craton with respect to Rodinia, available detrital zircon U-Pb ages and Hf isotopes from Meso- to Neoproterozoic sedimentary rocks were compiled. Comparable detrital zircon ages (at ca. 0.9, 1.3-1.1, and 1.7 Ga) and Hf isotopes indicate a close linkage among rocks of the southeastern Tarim craton, Cathaysia, and North India but exclude a northern or western Australian affinity. In addition, detrital zircons from the northern Tarim craton exhibit a prominent age peak at ca. 830 Ma with minor spectra at ca. 1.9 and 2.5 Ga but lack Mesoproterozoic ages, comparable to the northern and western Yangtze block. Together with comparable geological responses to the assembly and breakup of the Rodinia supercontinent, we offer a new perspective of the location of the Tarim craton between South China and North India in the periphery of Rodinia.

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A Tarim-South China-North India connection in the periphery of Rodinia: Constraints from provenance of middle Neoproterozoic sedimentary rocks in the Altyn Tagh orogen, southeastern Tarim

10.5194/egusphere-egu2020-2108 ◽

2020 ◽

Author(s):

Qian Liu

Keyword(s):

South China ◽

Detrital Zircon ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

Close Linkage ◽

North India ◽

Hf Isotopes ◽

Altyn Tagh ◽

Detrital Zircon Ages ◽

Rule Out

<p>Locating Tarim during assembly and breakup of Supercontinent Rodinia remains enigmatic, with different models advocating a Tarim-Australia linkage or a location between Australia and Laurentia at the heart of unified Rodinia. In this study, zircon U-Pb dating results first revealed middle Neoproterozoic sedimentary rocks in the Altyn Tagh orogen, southeastern Tarim. These sedimentary rocks were deposited between ca. 880 and 750 Ma in a rifting-related setting slightly prior to breakup of Rodinia at ca. 750 Ma. A compilation of Neoproterozoic geological records indicates that the Altyn Tagh orogen in southeastern Tarim underwent ca. 1.0-0.9 Ga collision and ca. 850-600 Ma rifting related to assembly and breakup of Rodinia, respectively. In order to place Tarim in Rodinia, available detrital zircon U-Pb ages and Hf isotopes from Meso- to Neoproterozoic sedimentary rocks in relevant Rodinia blocks are compiled. Comparable detrital zircon ages (at ca. 0.9, 1.3-1.1, and 1.7 Ga) and Hf isotopes indicate a close linkage among southeastern Tarim, Cathaysia, and North India, but rule out a North or West Australian affinity for Tarim. In addition, detrital zircons from northern Tarim exhibit a prominent age peak at ca. 830 Ma with minor spectra at ca. 1.9 and 2.5 Ga but lack Mesoproterozoic ages, which are comparable to those from northern and western Yangtze. Together with comparable geological responses to assembly and breakup of Rodinia, a new Tarim-South China-North India connection is inferred in the periphery of Rodinia.</p>

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Late Neoproterozoic to early Paleozoic paleogeographic position of the Yangtze block and the change of tectonic setting in its northwestern margin: Evidence from detrital zircon U-Pb ages and Hf isotopes of sedimentary rocks

Geological Society of America Bulletin ◽

10.1130/b35980.1 ◽

2021 ◽

Author(s):

Bingshuang Zhao ◽

Xiaoping Long ◽

Jin Luo ◽

Yunpeng Dong ◽

Caiyun Lan ◽

...

Keyword(s):

Detrital Zircon ◽

Tectonic Setting ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

Hf Isotopes ◽

Early Paleozoic ◽

Yangtze Block ◽

Sedimentary Provenance ◽

Northwestern Margin ◽

Late Neoproterozoic

The crustal evolution of the Yangtze block and its tectonic affinity to other continents of Rodinia and subsequent Gondwana have not been well constrained. Here, we present new U-Pb ages and Hf isotopes of detrital zircons from the late Neoproterozoic to early Paleozoic sedimentary rocks in the northwestern margin of the Yangtze block to provide critical constraints on their provenance and tectonic settings. The detrital zircons of two late Neoproterozoic samples have a small range of ages (0.87−0.67 Ga) with a dominant age peak at 0.73 Ga, which were likely derived from the Hannan-Micangshan arc in the northwestern margin of the Yangtze block. In addition, the cumulative distribution curves from the difference between the depositional age and the crystalline age (CA−DA) together with the mostly positive εHf(t) values of these zircon crystals (−6.8 to +10.7, ∼90% zircon grains with εHf[t] > 0) suggest these samples were deposited in a convergent setting during the late Neoproterozoic. In contrast, the Cambrian−Silurian sediments share a similar detrital zircon age spectrum that is dominated by Grenvillian ages (1.11−0.72 Ga), with minor late Paleoproterozoic (ca. 2.31−1.71 Ga), Mesoarchean to Neoarchean (3.16−2.69 Ga), and latest Archean to early Paleoproterozoic (2.57−2.38 Ga) populations, suggesting a significant change in the sedimentary provenance and tectonic setting from a convergent setting after the breakup of Rodinia to an extensional setting during the assembly of Gondwana. However, the presence of abundant Grenvillian and Neoarchean ages, along with their moderately to highly rounded shapes, indicates a possible sedimentary provenance from exotic continental terrane(s). Considering the potential source areas around the Yangtze block when it was a part of Rodinia or Gondwana, we suggest that the source of these early Paleozoic sediments had typical Gondwana affinities, such as the Himalaya, north India, and Tarim, which is also supported by their stratigraphic similarity, newly published paleomagnetic data, and tectono-thermal events in the northern fragments of Gondwana. This implies that after prolonged subduction in the Neoproterozoic, the northwestern margin of the Yangtze block began to be incorporated into the assembly of Gondwana and then accept sediments from the northern margin of Gondwanaland in a passive continental margin setting.

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A synopsis of mineral deposits in the Archean and Proterozoic rocks of the Lake Nipigon Region, Thunder Bay District, Ontario

Canadian Journal of Earth Sciences ◽

10.1139/e07-013 ◽

2007 ◽

Vol 44 (8) ◽

pp. 1041-1053 ◽

Cited By ~ 2

Author(s):

Mark C Smyk ◽

James M Franklin

Keyword(s):

Sedimentary Rocks ◽

Gold Deposits ◽

Hydrothermal Systems ◽

Mineral Deposit ◽

Iron Formation ◽

Banded Iron Formation ◽

Midcontinent Rift ◽

Copper Nickel ◽

Ultramafic Intrusion ◽

Lode Gold Deposits

A variety of metallic and non-metallic mineral deposit types occur within Archean and Proterozoic rocks in the area encompassing the Lake Nipigon Region Geoscience Initiative. Archean deposit types include Algoma-type banded iron formation-hosted iron (e.g., Lake Nipigon iron range); volcanogenic massive sulphide copper–zinc (e.g., Onaman–Tashota belt); ultramafic intrusion-hosted chromium (e.g., Puddy–Chrome lakes); mafic to ultramafic intrusion-hosted copper–nickel – platinum group element (PGE) (e.g., Lac des Iles); and pegmatite-hosted deposits of rare metals (Li, Ta, Be), uranium, and molybdenum (e.g., Georgia Lake field, Black Sturgeon Lake, and Anderson Lake, respectively). Mesothermal lode gold deposits are prominent in the Beardmore–Geraldton camp. Superior-type iron formation occurs in Paleoproterozoic Gunflint Formation. "Red-bed" copper occurs in Mesoproterozoic Midcontinent Rift-related Osler Group volcanic and interflow sedimentary rocks. Native copper and copper sulphides occur in Mesoproterozoic Sibley Group sedimentary rocks, adjacent to ultramafic intrusions. These mafic to ultramafic intrusions, associated with Midcontinent Rift magmatism, host copper–nickel–PGE deposits (e.g., Seagull, Great Lakes Nickel). Silver-bearing veins occur in Paleoproterozoic Animikie Group sedimentary rocks in proximity to Midcontinent Rift-related mafic intrusions (e.g., Silver Islet, Silver Mountain). Lead–zinc–barite veins, uranium-bearing veins, and amethyst vein and replacement-type deposits may be cogenetic and formed at or near the unconformity between Sibley Group basal sandstone and underlying Archean granitic basement (e.g., Dorion, Black Sturgeon Lake, McTavish Township). The hydrothermal systems that produced all of these veins were probably driven by heat associated with Midcontinent rifting. Many occur in structures related to rift-bounding faults. Iron oxide – copper–gold deposits may occur near the English Bay intrusion.

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The Central Slave Basement Complex, Part I: its structural topology and autochthonous cover

Canadian Journal of Earth Sciences ◽

10.1139/e98-102 ◽

1999 ◽

Vol 36 (7) ◽

pp. 1083-1109 ◽

Cited By ~ 112

Author(s):

Wouter Bleeker ◽

John WF Ketchum ◽

Valerie A Jackson ◽

Michael E Villeneuve

Keyword(s):

Detrital Zircon ◽

Hanging Wall ◽

Volcanic Rocks ◽

Iron Formation ◽

Structural Topology ◽

Banded Iron Formation ◽

Basement Complex ◽

South Central ◽

Slave Province ◽

Lake Formation

New field and geochronological data are used to define the distribution of Mesoarchean basement rocks in the south-central Slave Province. This distribution reflects a single contiguous basement terrane that we propose to call the Central Slave Basement Complex. It shows a structural topology that is internally consistent and compatible with known regional folding and faulting events. A sample of a proposed basement gneiss below the Courageous Lake greenstone belt, central Slave Province, has been dated by U-Pb methods and yields an age of 3325 ± 8 Ma, consistent with the new basement distribution. This sample also contains 2723 ± 3 Ma metamorphic zircon and ca. 2680 Ma titanite. The Central Slave Basement Complex is overlain by a thin, discontinuous, but distinctive cover sequence that includes minor volcanic rocks, clastic sedimentary rocks, and banded iron formation. All previously known and some new occurrences of this distinctive cover sequence occur in the immediate stratigraphic hanging wall of the Central Slave Basement Complex, locally overlying a preserved in situ unconformity. We propose to call this post-2.93 Ga cover sequence the Central Slave Cover Group. It is perhaps best typified by detrital chromite-bearing, fuchsitic quartzites. Formal formation names are proposed for the spatially separate occurrences of the Central Slave Cover Group. Detrital zircon ages are presented for one of the formations of the Central Slave Cover Group, the Patterson Lake Formation, which occurs on the western flank of a local basement culmination known as the Sleepy Dragon Complex. The detrital zircon data provide evidence for two discrete basement sources dated at ca. 2943 Ma and ca. 3147-3160 Ma. These detrital ages reinforce the depositional link between the Central Slave Cover Group and underlying crystalline rocks of the Central Slave Basement Complex.

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U–Pb detrital zircon constraints on active margin magmatism and sedimentation after the Grampian Orogeny in western Ireland

Journal of the Geological Society ◽

10.1144/jgs2020-093 ◽

2020 ◽

pp. jgs2020-093

Author(s):

Peter D. Clift ◽

Amy L. Luther ◽

Madison E. Avery ◽

Paul B. O'Sullivan

Keyword(s):

Detrital Zircon ◽

Analytical Data ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

Upper Ordovician ◽

Content Type ◽

Igneous Intrusions ◽

Supplementary Material ◽

Western Ireland ◽

Harbour Area

Early Ordovician collision of the Lough Nafooey Arc (part of the Baie Verte Oceanic Tract) with the passive continental margin of Laurentia peaked at c. 475 Ma in Scotland and Ireland and was followed by subduction polarity reversal. We examined Upper Ordovician–Silurian sedimentary rocks from western Ireland to see whether collision was followed by renewed arc magmatism. Despite the scarcity of dated igneous intrusions between the Grampian (c. 470 Ma) and Acadian (c. 420 Ma) orogenies in Ireland, detrital zircons show a continuity of activity peaking at 480–440 Ma, implying no hiatus in regional magmatism. Differences in zircon U–Pb age spectra highlight the isolation of basins in the southern Killary Harbour area from those north of the South Mayo Trough. These latter rocks were largely derived by erosion from Moine and Upper Dalradian sources. By contrast, the Killary Harbour Basin shows a decreasing influence from the Dalradian after c. 436 Ma and an increasing influence of contemporaneous magmatic zircons. These were transported from sources along-strike from the present NE, probably at the southern end of the Scandian Mountains in SE Greenland. The western Irish basins formed as pull-apart basins in a forearc setting and are analogous to Cenozoic pull-apart basins in Sumatra.Supplementary material: U-Pb zircon analytical data is available at a decreasing influence from the Dalradian after c. 436 Ma and an increasing influence of contemporaneous https://doi.org/10.6084/m9.figshare.c.5209849

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Supplemental Material: Late Neoproterozoic to early Paleozoic paleogeographic position of the Yangtze block and the change of tectonic setting in its northwestern margin: Evidence from detrital zircon U-Pb ages and Hf isotopes of sedimentary rocks

10.1130/gsab.s.14390390.v1 ◽

2021 ◽

Author(s):

Bingshuang Zhao ◽

Xiaoping Long ◽

et al.

Keyword(s):

Detrital Zircon ◽

Tectonic Setting ◽

Sedimentary Rocks ◽

Detrital Zircons ◽

Early Paleozoic ◽

Yangtze Block ◽

Isotopic Data ◽

Northwestern Margin ◽

Late Neoproterozoic

Supplementary Figure S1: Representative cathodoluminescence images of zircons from the northwestern Yangtze block samples; Supplementary Table S1: U–Pb dating results and in situ Lu–Hf isotopic data for detrital zircons from the northwestern Yangtze block samples.

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The Proterozoic Guanhães banded iron formations, Southeastern border of the São Francisco Craton, Brazil: evidence of detrital contamination

Geologia USP Série Científica ◽

10.11606/issn.2316-9095.v17-352 ◽

2017 ◽

Vol 17 (2) ◽

pp. 303 ◽

Cited By ~ 7

Author(s):

Vitor Rodrigues Barrote ◽

Carlos Alberto Rosiere ◽

Vassily Khoury Rolim ◽

João Orestes Schneider Santos ◽

Neal Jesse Mcnaughton

Keyword(s):

Detrital Zircons ◽

Iron Formation ◽

Geochemical Data ◽

Banded Iron Formations ◽

Banded Iron Formation ◽

Zircon Age ◽

Shallow Marine ◽

Eu Anomaly ◽

Depositional Age ◽

Iron Formations

The Guanhães banded iron formation (BIF) bearing succession occurs as tectonic slices, juxtaposed to Archean TTG granite-gneissic basement rock, developed during the Neoproterozoic-Cambrian Brasiliano collage. The succession has a maximum depositional age of ~2.18 Ga, from detrital zircons in quartzite, and consists of quartzites, schists, BIFs, gneiss and amphibolite, all metamorphosed under amphibolite facies conditions. The Guanhães BIF shows HREE enrichment and consistent positive Eu anomaly (PAAS-normalized REE+Y). Two types of contamination were observed in the samples. The first is contamination by an exotic detrital component, which resulted in low Y/Ho (<30) and Pr/Yb (SN) ratios. Evidence of such contamination, combined with inferred stratigraphic stacking data, indicates that the Guanhães BIFs were deposited on a shallow marine environment. The second type of contamination resulted in higher Eu-anomalies, positive Ce-anomalies, and higher REE+Y concentrations, possibly due to the interaction between later magmatic fluids and the Guanhães BIF. A strong Cambrian event is recorded in zircon age data. The uncontaminated samples display REE+Y distribution similar to other Precambrian BIFs, particularly those from the Morro-Escuro Sequence and the Serra da Serpentina Group, without true Ce-anomalies and Y/Ho close to seawater values (45). Geochronological and geochemical data presented in this paper strongly suggest a correlation between the Guanhães supracrustal succession and the Serra da Serpentina and Serra de São José Groups.

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