The age and origin of the North Shore Plutons in the Rae Province, Goldfields area, Saskatchewan

1994 ◽  
Vol 31 (9) ◽  
pp. 1397-1406 ◽  
Author(s):  
David S. O'Hanley ◽  
T. Kurtis Kyser ◽  
Thomas I. I. Sibbald
Keyword(s):  
Detrital Zircons ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
North Shore ◽  
The North ◽  
Evaporation Technique ◽  
Single Zircon ◽  
Archean Crust ◽  
Host Rocks ◽  
Isotope Systematics

The North Shore Plutons are peraluminous granitoids emplaced within the Murmac Bay Group supracrustals exposed on the north shore of Lake Athabasca, Saskatchewan. 207Pb/206Pb ages obtained using the single-zircon Pb-evaporation technique indicate emplacement at 1952 ± 18 Ma, coeval with Taltson magmatism that occurred during the 1.9–2.0 Ga Thelon orogeny, which influenced the Rae Province. The granitoids inherited zircons from Archean source terranes dated at approximately 2.5 and 3.0 Ga. Detrital zircons from the younger source terrane were also identified in the Murmac Bay Group, thus constraining the maximum age of the group to the Paleoproterozoic.Rare earth element and incompatible element data and Rb–Sr and Sm–Nd isotope systematics from the North Shore Plutons and adjacent host rocks indicate that the plutons are crustal melts generated from melting of Murmac Bay Group rocks and Archean crust at deeper levels. Granitic gneisses described as "Older" Granites represent mixtures of variable amounts of magmatic fluids similar to those that formed the North Shore plutons and the Murmac Bay Group metasedimentary rocks.

scholarly journals Dating the Sedimentary Protolith of the Daldyn Group Quartzite, Anabar Shield, Russia: New Detrital Zircon Constraints

Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 208
Author(s):  
Nikolay I. Gusev ◽  
Lyudmila Yu. Sergeeva ◽  
Sergey G. Skublov
Keyword(s):  
Detrital Zircon ◽  
Granulite Facies ◽  
Detrital Zircons ◽  
Nd Isotope ◽  
Granulite Facies Metamorphism ◽  
Metasedimentary Rocks ◽  
Archean Rock ◽  
Facies Metamorphism ◽  
Anabar Shield ◽  
Isotope Systematics

Quartzites and paragneisses of the Archean granulite series of the Anabar Shield (Siberian Craton, Russia) are described geochemically. The Sm-Nd isotope systematics of the rocks and the U-Pb age (SHRIMP II) and geochemistry of zircons from quartzites and paragneisses are studied. Newly formed zircons from quartzites display geochemical characteristics of the magmatic type and were produced by rock anatexis upon granulite-facies metamorphism. The Paleoproterozoic age of the latest detrital zircons, 2250 ± 24 Ma, constrains the maximum age of sedimentary rock deposition. The anatectic rims around detrital zircons were formed ca. 2000 ± 9 Ma ago. The time of deposition of the sedimentary protolith of gneisses and quartzites falls within the age interval of the above-mentioned dates and is tentatively accepted as 2.1 Ga. The presence of Paleoproterozoic metasedimentary rocks in the Daldyn Group implies the tectonic heterogeneity of the series and the existence of Paleoproterozoic rock bodies among the predominant Archean rock sequences.

scholarly journals The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia

2018 ◽  
Vol 45 (3) ◽  
pp. 301 ◽  
Author(s):  
Francisco Hervé ◽  
Mauricio Calderón ◽  
Mark Fanning ◽  
Robert Pankhurst ◽  
Carlos W. Rapela ◽  
...  
Keyword(s):  
Metamorphic Grade ◽  
Oceanic Island ◽  
Detrital Zircons ◽  
Island Arc ◽  
Ultramafic Rocks ◽  
The West ◽  
Metasedimentary Rocks ◽  
The North ◽  
The Andes ◽  
Late Neoproterozoic

Previous work has shown that Devonian magmatism in the southern Andes occurred in two contemporaneous belts: one emplaced in the continental crust of the North Patagonian Massif and the other in an oceanic island arc terrane to the west, Chaitenia, which was later accreted to Patagonia. The country rocks of the plutonic rocks consist of metasedimentary complexes which crop out sporadically in the Andes on both sides of the Argentina-Chile border, and additionally of pillow metabasalts for Chaitenia. Detrital zircon SHRIMP U-Pb age determinations in 13 samples of these rocks indicate maximum possible depositional ages from ca. 370 to 900 Ma, and the case is argued for mostly Devonian sedimentation as for the fossiliferous Buill slates. Ordovician, Cambrian-late Neoproterozoic and “Grenville-age” provenance is seen throughout, except for the most westerly outcrops where Devonian detrital zircons predominate. Besides a difference in the Precambrian zircon grains, 76% versus 25% respectively, there is no systematic variation in provenance from the Patagonian foreland to Chaitenia, so that the island arc terrane must have been proximal to the continent: its deeper crust is not exposed but several outcrops of ultramafic rocks are known. Zircons with devonian metamorphic rims in rocks from the North Patagonian Massif have no counterpart in the low metamorphic grade Chilean rocks. These Paleozoic metasedimentary rocks were also intruded by Pennsylvanian and Jurassic granitoids.

scholarly journals Nd isotope mapping of the Grenvillian Allochthon Boundary Thrust in Algonquin Park, Ontario

2019 ◽  
Vol 56 (2) ◽  
pp. 101-110 ◽  
Author(s):  
A.P. Dickin ◽  
J.W.D. Strong
Keyword(s):  
High Grade ◽  
Geographical Pattern ◽  
Precise Location ◽  
Nd Isotope ◽  
North Shore ◽  
The North ◽  
Digital Elevation ◽  
Elevation Data ◽  
Digital Elevation Data ◽  
Isotope Analyses

Over 50 new Nd isotope analyses are presented for high-grade orthogneisses from Algonquin Park and surrounding region to map major Grenvillian thrust boundaries. Nd model ages display a consistent geographical pattern that allows detailed mapping of the boundary between the Algonquin and Muskoka domains, here interpreted as the local trajectory of the Ottawan-age Allochthon Boundary Thrust (ABT). The ABT is underlain by a domain with Paleoproterozoic Nd model ages, interpreted as a tectonic duplex entrained onto the base of the main allochthon. The boundaries determined using Nd isotope mapping are consistent with field mapping and with remotely sensed aeromagnetic and digital elevation data. The precise location of the ABT can be observed in a road-cut on Highway 60, on the north shore of Lake of Two Rivers in the centre of Algonquin Park.

scholarly journals Age and sources of the metasedimrntary rocks of the Tokur terrane in the Mongol-Okhotsk fold belt: results of the U–Pb geoсhronological and Lu–Hf isotope studies

2019 ◽  
Vol 486 (4) ◽  
pp. 446-450
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin ◽  
A. P. Sorokin
Keyword(s):  
Detrital Zircons ◽  
Hf Isotope ◽  
Fold Belt ◽  
Metasedimentary Rocks ◽  
The North ◽  
Icp Ms ◽  
North Asia ◽  
Southeastern Margin ◽  
Isotope Studies ◽  
Metamorphic Complexes

This paper presents the results of U–Pb (LA–ICP–MS) and Lu–Hf ­isotope studies of detrital zircons from metasedimentary rocks of the Tokur Terrane. It has been shown that metasedimentary rocks of the Tokur and Ekimchan formations are characterized by similar age peaks of detrital zircons, which indicates a close (or same) age of these formations. The lower age of the sedimentation is determined by the age of the youngest zircons of 326–323 Ma. The upper age boundary is determined of 254–251 Ma, based on the intruded of the Late Permian granitoids. The main sources of zircons in the metasedimentary rocks of the Tokur Terrane are the igneous and metamorphic complexes of the southeast framing of the North Asia Craton. The Tokur Terrane can be considered as a fragment of the Paleozoic accretionary complex, the formation in front of the southeastern margin of the North Asia Craton.

Age and source of detrital zircons from the Missi Formation: a Proterozoic molasse deposit, Trans-Hudson Orogen, Canada

1992 ◽  
Vol 29 (12) ◽  
pp. 2583-2594 ◽  
Author(s):  
Kevin M. Ansdell ◽  
T. Kurtis Kyser ◽  
Mel R. Stauffer ◽  
Garth Edwards
Keyword(s):  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Early Proterozoic ◽  
Minimum Age ◽  
Granitoid Rocks ◽  
Evaporation Technique ◽  
Single Zircon ◽  
Flin Flon ◽  
Felsic Volcanic

The Missi Formation in the Flin Flon Basin forms part of a discontinuous series of molasse-type sediments found throughout the Early Proterozoic Trans-Hudson Orogen in northern Saskatchewan and Manitoba. The Flin Flon Basin contains a sequence of proximal-fan to braided-stream fluvial conglomerates and sandstones, which unconformably overlie subaerially weathered Amisk Group volcanic rocks. Stratigraphic way-up indicators have been preserved, even though these rocks have undergone greenschist-facies metamorphism and polyphase deformation. The sedimentary rocks are crosscut by intrusive rocks, which provide a minimum age of sedimentation of 1840 ± 7 Ma.Detrital zircons from each of the six stratigraphic subdivisions of the Flin Flon Basin were analyzed using the single-zircon Pb-evaporation technique. Euhedral to slightly rounded zircons dominate each sample, and these zircons give ages of between about 1854 and 1950 Ma. The Missi sediments were thus deposited between 1840 and 1854 Ma. Possible sources for the detrital zircons are Amisk Group felsic volcanic rocks and post-Amisk granitoid rocks and orthogneisses in adjacent domains within the Trans-Hudson Orogen. However, the immature character of the sedimentary rocks, the composition of clasts, the euhedral character of many of the zircons, and the range in ages suggest that most were likely derived from Amisk Group and granitoid rocks in the western Flin Flon Domain. Rounded zircons are uncommon but provide evidence for the reworking of older Proterozoic sedimentary rocks, or a distant Archean or Early Proterozoic granitoid terrane.

U–Pb geochronology of detrital zircons from a continental margin assemblage in the northern Coast Mountains, southeastern Alaska

1991 ◽  
Vol 28 (8) ◽  
pp. 1285-1300 ◽  
Author(s):  
George E. Gehrels ◽  
William C. McClelland ◽  
Scott D. Samson ◽  
P. Jonathan Patchett
Keyword(s):  
Continental Margin ◽  
North American ◽  
Detrital Zircons ◽  
Northern Coast ◽  
Coast Mountains ◽  
Metasedimentary Rocks ◽  
The North ◽  
Upper Proterozoic ◽  
Two Samples ◽  
Cordilleran Margin

Metamorphic rocks within and west of the northern Coast Mountains in southeastern Alaska consist of an Upper Proterozoic(?) to upper Paleozoic continental margin assemblage that we interpret to belong to the Yukon-Tanana terrane. U–Pb geochronologic analyses of single detrital zircon grains from four samples of quartzite suggest that the zircons were shed from source regions containing rocks of ~495 Ma, ~750 Ma, 1.05–1.40 Ga, 1.75–2.00 Ga, ~2.3 Ga, 2.5–2.7 Ga, and ~3.0 Ga. Multigrain fractions from two samples yield upper intercepts between 2.0 and 2.3 Ga, but the scarcity of single grains of similar age suggests that these fractions comprise a mixture of < 2.0 and > 2.3 Ga grains. Zircons in these rocks generally overlap in age with (i) detrital zircons in metasedimentary rocks of the Yukon–Tanana terrane in eastern Alaska and Yukon, (ii) detrital zircons in strata of the Cordilleran miogeocline, and (iii) plutonic and gneissic rocks that intrude or are overlain by miogeoclinal strata. In addition, the pre-1.7 Ga grains overlap in age with dated crystalline rocks of the western Canadian Shield. These similarities raise the possibility that metaclastic rocks in the northern Coast Mountains accumulated in proximity to western North America. The younger zircon populations were likely shed from mid-Proterozoic to early Paleozoic igneous rocks that now occur locally (but may have been widespread) along the Cordilleran margin. Recognition of a continental margin assemblage of possible North American affinity in the Coast Mountains raises the possibility that some arc-type and oceanic terranes inboard of the Coast Mountains may be large klippen that have been thrust over the North American margin.

U–Pb and Hf isotopic study of detrital zircons from the Lüliang khondalite, North China Craton, and their tectonic implications

2009 ◽  
Vol 146 (5) ◽  
pp. 701-716 ◽  
Author(s):  
XIAOPING XIA ◽  
MIN SUN ◽  
GUOCHUN ZHAO ◽  
FUYUAN WU ◽  
LIEWEN XIE
Keyword(s):  
North China Craton ◽  
North China ◽  
Detrital Zircons ◽  
Crustal Material ◽  
Isotopic Data ◽  
Isotopic Study ◽  
Metasedimentary Rocks ◽  
The North ◽  
Wide Range ◽  
Western Block

AbstractTwo types of metasedimentary rocks occur in the Trans-North China Orogen of the North China Craton. One type consists of highly metamorphosed supracrustal rocks with protoliths of mature cratonic shale, called khondalites, as found in the Lüliang Complex; rocks of the other type are also highly metamorphosed but less mature, as represented by the Wanzi supracrustal assemblage in the Fuping Complex. U–Pb isotopic data for detrital zircons from khondalites show a provenance dominated by 1.9–2.1 Ga Palaeoproterozoic rocks. These detrital zircons display a wide range of εHfvalues from −16.0 to +9.2 and give Hf isotopic model ages mostly around 2.3 Ga. The high positive εHfvalues approach those for the depleted mantle at 2.1 Ga, highlighting a juvenile crustal growth event in Palaeoproterozoic times. Hf isotopic data also imply thatc.2.6 Ga old crustal material was involved in the Palaeoproterozoic magmatic event. These data are similar to those for the khondalitic rocks from the interior of the Western Block of the North China Craton, suggesting a common provenance. In contrast, other metasedimentary rocks in the Trans-North China Orogen, such as the Wanzi supracrustal assemblage in the Fuping Complex, have a source region with both Palaeoproterozoic and Archaean rocks. Their detrital zircon Hf isotopic data indicate reworking of old crustal material and a lack of significant juvenile Palaeoproterozoic magmatic input. These rocks are similar to the coevally deposited meta-sedimentary rocks in the interior of the Eastern Block. We propose that the Lüliang khondalites were deposited on the eastern margin of the Western Block in a passive continental margin environment and were thrust eastward later during collision with the Eastern Block. Other metasedimentary rocks in the Trans-North China Orogen were deposited on the western margin of the Eastern Block in a continental arc environment. Our data support the eastward subduction model for the Palaeoproterozoic tectonic evolution of the North China Craton.

scholarly journals Zircon geochronology from the Kangaatsiaq– Qasigiannguit region, the northern part of the 1.9–1.8 Ga Nagssugtoqidian orogen, West Greenland

2006 ◽  
Vol 11 ◽  
pp. 87-100 ◽  
Author(s):  
Kristine Thrane ◽  
James N. Connelly
Keyword(s):  
Detrital Zircons ◽  
Zircon Geochronology ◽  
West Greenland ◽  
Metasedimentary Rocks ◽  
The North ◽  
Ion Probe ◽  
Icp Ms ◽  
Supracrustal Belt ◽  
Granitoid Rocks ◽  
Age Patterns

The Kangaatsiaq–Qasigiannguit region in the northern part of the Palaeoproterozoic Nagssugtoqidian orogen of West Greenland consists of poly-deformed orthogneisses and minor occurrences of interleaved, discontinuous supracrustal belts. Laser ablation ICP-MS 207Pb/206Pb analyses of detrital zircons from four metasedimentary rocks (supplemented by ion probe analysis of one sample) and igneous zircons from six granitoid rocks cutting metasedimentary units indicate that the supracrustal rocks in the Kangaatsiaq–Qasigiannguit (Christianshåb) region are predominantly Archaean in age. Four occurrences of metasedimentary rocks are clearly Archaean, two have equivocal ages, and only one metasedimentary unit, from within the Naternaq (Lersletten) supracrustal belt, is demonstrably Palaeoproterozoic and readily defines a large fold complex of this age at Naternaq. The 2.9–2.8 Ga ages of detrital Archaean grains are compatible with derivation from the local basement orthogneisses within the Nagssugtoqidian orogen. The detrital age patterns are similar to those of metasediments within the central Nagssugtoqidian orogen but distinct from age patterns in metasediments of the Rinkian belt to the north, where there is an additional component of pre-2.9 Ga zircons. Synkinematic intrusive granitoid rocks constrain the ages of some Archaean deformation at 2748 ± 19 Ma and some Palaeoproterozoic deformation at 1837 ± 12 Ma.

scholarly journals Age and sources of the Lower Mesozoic metasedimentary rocks of the Un'ja-Bom terrane in the Mongol-Okhotsk fold belt: results of the U–Th–Pb geohronological (LA–ICP–MS) AND Sm–Nd isotope studies

2019 ◽  
Vol 484 (4) ◽  
pp. 455-459
Author(s):  
V. A. Zaika ◽  
A. A. Sorokin ◽  
V. P. Kovach ◽  
A. P. Sorokin ◽  
A. B. Kotov
Keyword(s):  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Fold Belt ◽  
Relative Probability ◽  
Nd Isotope ◽  
Metasedimentary Rocks ◽  
Icp Ms ◽  
Isotope Studies ◽  
Geochemical Studies ◽  
Age Estimates

The results of the U—Th—Pb geochronological studies indicate that in the Un’ja-Bom terrane the youngest peaks on the relative probability curves of ages are 207 and 212 Ma for zircons from the metasiltstone of the Kurnal formation and from the metasiltstone of the Amkan formation. Similar age estimates for the youngest peaks were obtained for the detrital zircons from the metasedimentary rocks of the Tukuringra terrain of the eastern part of the Mongol-Okhotsk belt, which indicates that the Lower Mesozoic flyschoid complexes in the structure of this belt are developed much wider than is currently believed. The results obtained in our U—Th—Pb geochronological and Sm—Nd isotope geochemical studies suggest’s that the sedimentary rocks material was carried to the sedimentation basin mainly from the continental massifs of the Amur superterrane.

Crustal segments in the North Patagonian Massif, Patagonia: An integrated perspective based on Sm–Nd isotope systematics

2011 ◽  
Vol 31 (2-3) ◽  
pp. 324-341 ◽  
Author(s):  
Carmen I. Martínez Dopico ◽  
Mónica G. López de Luchi ◽  
Augusto E. Rapalini ◽  
Ilka C. Kleinhanns
Keyword(s):  
Nd Isotope ◽  
The North ◽  
Isotope Systematics
Sign in / Sign up

Export Citation Format

Share Document