U–Pb geochronology of detrital zircons in metasedimentary rocks from southern Baffin Island: implications for the Paleoproterozoic tectonic evolution of Northeastern Laurentia

2002 ◽  
Vol 39 (5) ◽  
pp. 611-623 ◽  
Author(s):  
David J Scott ◽  
Richard A Stern ◽  
Marc R St-Onge ◽  
Sarah M McMullen

A geochronological investigation of metasedimentary rocks from southern Baffin Island using the Geological Survey of Canada SHRIMP II (sensitive high-resolution ion microprobe) has characterized the ages of detrital zircon populations to determine their provenance, bracket timing of deposition, and distinguish potentially distinct sequences of rocks. Four lithologically and structurally distinct metasedimentary packages have been identified; each appears to have been derived from a different source region. In the structurally lowest package, all analysed zircons are Archean, and > 90% have ages between 2.83 and 2.63 Ga; these rocks are interpreted as the northernmost exposures of the Paleoproterozoic Povungnituk Group of the Cape Smith Belt, northern Quebec, with detritus derived from the Superior craton. Occupying the intermediate structural levels, the most abundant supracrustal rocks on southern Baffin Island are siliciclastic and carbonate units of the Lake Harbour Group, and the Tasiuyak paragneiss. Five samples show a dominantly Paleoproterozoic signature (2.2–1.9 Ga), with only rare Archean zircons; the provenance of this detritus is uncertain. In the distinct package of feldspathic quartzite and pelite that stratigraphically overlies the Lake Harbour Group, all of the analysed detrital grains are Archean, ~80% are > 2.83 Ga, with a small proportion of the grains in excess of 3.0 Ga; all of this material is thought to be derived from the Archean craton exposed on the Hall Peninsula east of the study area. Finally, at the highest structural level, a sample associated with the Hall Peninsula orthogneisses contains zircons with prominent modes at 2.92, 2.82, and 2.77 Ga, consistent with derivation from the surrounding orthogneisses.

2011 ◽  
Vol 48 (2) ◽  
pp. 515-541 ◽  
Author(s):  
Yvon Lemieux ◽  
Thomas Hadlari ◽  
Antonio Simonetti

U–Pb ages have been determined on detrital zircons from the Upper Devonian Imperial Formation and Upper Devonian – Lower Carboniferous Tuttle Formation of the northern Canadian Cordilleran miogeocline using laser ablation – multicollector – inductively coupled plasma – mass spectrometry. The results provide insights into mid-Paleozoic sediment dispersal in, and paleogeography of, the northern Canadian Cordillera. The Imperial Formation yielded a wide range of detrital zircon dates; one sample yielded dominant peaks at 1130, 1660, and 1860 Ma, with smaller mid-Paleozoic (∼430 Ma), Neoproterozoic, and Archean populations. The easternmost Imperial Formation sample yielded predominantly late Neoproterozoic – Cambrian zircons between 500 and 700 Ma, with lesser Mesoproterozoic and older populations. The age spectra suggest that the samples were largely derived from an extensive region of northwestern Laurentia, including the Canadian Shield, igneous and sedimentary provinces of Canada’s Arctic Islands, and possibly the northern Yukon. The presence of late Neoproterozoic – Cambrian zircon, absent from the Laurentian magmatic record, indicate that a number of grains were likely derived from an exotic source region, possibly including Baltica, Siberia, or Arctic Alaska – Chukotka. In contrast, zircon grains from the Tuttle Formation show a well-defined middle Paleoproterozoic population with dominant relative probability peaks between 1850 and 1950 Ma. Additional populations in the Tuttle Formation are mid-Paleozoic (∼430 Ma), Mesoproterozoic (1000–1600 Ma), and earlier Paleoproterozoic and Archean ages (>2000 Ma). These data lend support to the hypothesis that the influx of sediments of northerly derivation that supplied the northern miogeocline in Late Devonian time underwent an abrupt shift to a source of predominantly Laurentian affinity by the Mississippian.


1996 ◽  
Vol 33 (7) ◽  
pp. 1087-1104 ◽  
Author(s):  
N. Wodicka ◽  
R. A. Jamieson ◽  
R. R. Parrish

We report U–Pb zircon ages for metaplutonic and metasedimentary rocks from three lithotectonic assemblages within the Parry Sound allochthon of the Central Gneiss Belt, southwestern Grenville Orogen: the basal Parry Sound, interior Parry Sound, and Twelve Mile Bay assemblages. Magmatic crystallization ages for granitic to tonalitic gneisses from the basal Parry Sound assemblage fall in the range 1400–1330 Ma. Younger intrusions include the Parry Island anorthosite dated at 1163 ± 3 Ma and a crosscutting mafic dyke bracketed between 1151 and 1163 Ma. Dated at [Formula: see text] a tonalitic gneiss from the overlying interior Parry Sound assemblage is slightly younger than the older group of rocks from the basal Parry Sound assemblage. 207Pb/206Pb ages for zircons from a quartzite of the basal Parry Sound assemblage range from 1385 Ma to the Neoarchaean. An absolute maximum age for this quartzite is 1436 ± 17 Ma. In contrast, detrital zircons from a quartzite of the Twelve Mile Bay assemblage constrain the age of deposition at post-ca. 1140–1120 Ma. We speculate that Grenvillian-age zircons within this quartzite were derived from rocks in the Adirondack Highlands and Frontenac terrane, implying that part of the Parry Sound domain and these terranes were contiguous during deposition of the quartzite. Our data support previous interpretations that the Parry Sound domain is allochthonous with respect to its surroundings, and suggest that the most likely source region of the basal Parry Sound domain lies southeast of the Central Gneiss Belt, within the Central Metasedimentary Belt boundary thrust zone or the Adirondack Highlands. This implies the possibility of 100–300 km of displacement of the domain. Emplacement of the Parry Sound domain into its present position must have occurred relatively late in the orogen's history, by about 1080 Ma.


2009 ◽  
Vol 146 (6) ◽  
pp. 903-916 ◽  
Author(s):  
M. J. FLOWERDEW ◽  
D. M. CHEW ◽  
J. S. DALY ◽  
I. L. MILLAR

AbstractThe presence of major crystalline basement provinces at depth in NW Ireland is inferred from in situ Hf isotope analysis of zircons from granitoid rocks that cut structurally overlying metasedimentary rocks. Granitoids in two of these units, the Slishwood Division and the Tyrone Central Inlier, contain complex zircons with core and rim structures. In both cases, cores have average ϵHf values that differ from the average ϵHf values of the rims at 470 Ma (the time of granitoid intrusion). The Hf data and similarity in U–Pb age between the inherited cores and detrital zircons from the host metasedimentary rocks suggests local contamination during intrusion rather than transport of the grains from the source region at depth. Rims from the Slishwood Division intrusions have average ϵHf470 values of −7.7, consistent with a derivation from juvenile Palaeoproterozoic crust, such as the Annagh Gneiss Complex or Rhinns Complex of NW Ireland, implying that the deep crust underlying the Slishwood Division is made of similar material. Rims from the Tyrone Central Inlier have extremely negative ϵHf470 values of approximately −39. This isotopic signature requires an Archaean source, suggesting rocks similar to the Lewisian Complex of Scotland, or sediment derived wholly from it, occurs at depth in NW Ireland.


1991 ◽  
Vol 28 (8) ◽  
pp. 1254-1270 ◽  
Author(s):  
Gerald M. Ross ◽  
Randall R. Parrish

We address two problems of Cordilleran geology in this study using U–Pb dating of single detrital zircon grains from metasedimentary rocks: the provenance of the Windermere Supergroup, and the age and correlation of metasedimentary rocks within the Shuswap Complex that are at high metamorphic grade. Because some of these rocks are clearly of North American affinity, the ages of zircons provide indirect constraints on the age and distribution of continental basement from which the zircons were derived.A consistent pattern emerges from ages of about 50 grains from six rocks. Nearly all samples analyzed (48–53°N) are characterized by a bimodal distribution of zircon ages of 1.65–2.16 Ga and > 2.5 Ga, with a distinct lack of ages between 2.1 and 2.5 Ga. Exceptions to this pattern are young zircons from two samples, from Valhalla and Grand Forks – Kettle complexes of southeastern British Columbia, that have grains 1435 ± 35 and 650 ± 15 Ma, respectively. These younger grains are inferred to have been derived from magmatic rocks, and they have no obvious source in either the Canadian Shield or the Alberta subsurface basement to the east. The Early Proterozoic and Archean ages of detrital zircons resemble those of dated basement rocks beneath the Alberta Basin as well as basement exposed within the Cordilleran hinterland (gneisses of Thor–Odin, Frenchman Cap, and Malton regions). However, 2.1–2.4 Ga rocks that are extensive in the subsurface of northern Alberta are not represented in the inventory of detrital zircon ages presented in this paper.This pattern suggests that much of the Cordilleran basement between these latitudes is underlain by Archean crust of the Hearne–Wyoming provinces that may be mantled to the west by an orogenic–magmatic belt of Early Proterozoic (1.7–1.9 Ga) age which may largely have been parallel to the present Cordilleran orogen.


2019 ◽  
Vol 70 (4) ◽  
pp. 298-310
Author(s):  
Anna Vozárová ◽  
Nickolay Rodionov ◽  
Katarína Šarinová

Abstract U–Pb (SHRIMP) detrital zircon ages from the Early Paleozoic meta-sedimentary rocks of the Northern Gemericum Unit (the Smrečinka Formation) were used to characterize their provenance. The aim was to compare and reconcile new analyses with previously published data. The detrital zircon age spectrum demonstrates two prominent populations, the first, Late Neoproterozoic (545–640 Ma) and the second, Paleoproterozoic (1.8–2.1 Ga), with a minor Archean population (2.5–3.4 Ga). The documented zircon ages reflect derivation of the studied metasedimentary rocks from the Cadomian arc, which was located along the West African Craton. The acquired data supports close relations of the Northern Gemericum basement with the Armorican terranes during Neoproterozoic and Ordovician times and also a close palinspastic relation with the other crystalline basements of the Central Western Carpathians. In comparison, the detrital zircons from the Southern Gemericum basement and its Permian envelope indicate derivation from the Pan-African Belt–Saharan Metacraton provenance.


2017 ◽  
Vol 155 (5) ◽  
pp. 1063-1088 ◽  
Author(s):  
JIALIN WANG ◽  
CHAODONG WU ◽  
ZHUANG LI ◽  
WEN ZHU ◽  
TIANQI ZHOU ◽  
...  

AbstractField-based mapping, sandstone petrology, palaeocurrent measurements and zircon cathodoluminescence images, as well as detrital zircon U–Pb geochronology were integrated to investigate the provenance of the Upper Carboniferous – Upper Triassic sedimentary rocks from the northern Bogda Mountains, and further to constrain their tectonic evolution. Variations in sandstone composition suggest that the Upper Carboniferous – Lower Triassic sediments displayed less sedimentary recycling than the Middle–Upper Triassic sediments. U–Pb isotopic dating using the LA-ICP-MS method on zircons from 12 sandstones exhibited similar zircon U–Pb age distribution patterns with major age groups at 360–320 Ma and 320–300 Ma, and with some grains giving ages of > 541 Ma, 541–360 Ma, 300–250 Ma and 250–200 Ma. Coupled with the compiled palaeocurrent data, the predominant sources were the Late Carboniferous volcanic rocks of the North Tianshan and Palaeozoic magmatic rocks of the Yili–Central Tianshan. There was also input from the Bogda Mountains in Middle–Late Triassic time. The comprehensive geological evidence indicates that the Upper Carboniferous – Lower Permian strata were probably deposited in an extensional context which was related to a rift or post-collision rather than arc-related setting. Conspicuously, the large range of U–Pb ages of the detrital zircons, increased sedimentary lithic fragments, fluvial deposits and contemporaneous Triassic zircon ages argue for a Middle–Late Triassic orogenic movement, which was considered to be the initial uplift of the Bogda Mountains.


2022 ◽  
Author(s):  
Elizabeth L. Miller ◽  
Mark E. Raftrey ◽  
Jens-Erik Lund Snee

ABSTRACT In a reconnaissance investigation aimed at interrogating the changing topography and paleogeography of the western United States prior to Basin and Range faulting, a preliminary study made use of U-Pb ages of detrital zircon suites from 16 samples from the Eocene–Oligocene Titus Canyon Formation, its overlying units, and correlatives near Death Valley. The Titus Canyon Formation unconformably overlies Neoproterozoic to Devonian strata in the Funeral and Grapevine Mountains of California and Nevada. Samples were collected from (1) the type area in Titus Canyon, (2) the headwaters of Monarch Canyon, and (3) unnamed Cenozoic strata exposed in a klippe of the Boundary Canyon fault in the central Funeral Mountains. Red beds and conglomerates at the base of the Titus Canyon Formation at locations 1 and 2, which contain previously reported 38–37 Ma fossils, yielded mostly Sierran batholith–age detrital zircons (defined by Triassic, Jurassic, and Cretaceous peaks). Overlying channelized fluvial sandstones, conglomerates, and minor lacustrine shale, marl, and limestone record an abrupt change in source region around 38–36 Ma or slightly later, from more local, Sierran arc–derived sediment to extraregional sources to the north. Clasts of red radiolarian-bearing chert, dark radiolarian chert, and quartzite indicate sources in the region of the Golconda and Roberts Mountains allochthons of northern Nevada. Sandstones intercalated with conglomerate contain increasing proportions of Cenozoic zircon sourced from south-migrating, caldera-forming eruptions at the latitude of Austin and Ely in Nevada with maximum depositional ages (MDAs) ranging from 36 to 24 Ma at the top of the Titus Canyon Formation. Carbonate clasts and ash-rich horizons become more prevalent in the overlying conglomeratic Panuga Formation (which contains a previously dated 15.7 Ma ash-flow tuff). The base of the higher, ash-dominated Wahguyhe Formation yielded a MDA of 14.4 Ma. The central Funeral Mountains section exposes a different sequence of units that, based on new data, are correlative to the Titus Canyon, Panuga, and Wahguyhe Formations at locations 1 and 2. An ash-flow tuff above its (unexposed) base provided a MDA of 34 Ma, and the youngest sample yielded a MDA of 12.7 Ma. The striking differences between age-correlative sections, together with map-based evidence for channelization, indicate that the Titus Canyon Formation and overlying units likely represent fluvial channel, floodplain, and lacustrine deposits as sediments mostly bypassed the region, moving south toward the Paleogene shoreline in the Mojave Desert. The profound changes in source regions and sedimentary facies documented in the Titus Canyon Formation took place during ignimbrite flareup magmatism and a proposed eastward shift of the continental divide from the axis of the Cretaceous arc to a new divide in central Nevada in response to thermal uplift and addition of magma to the crust. This uplift initiated south-flowing fluvial systems that supplied sediments to the Titus Canyon Formation and higher units.


2002 ◽  
Vol 39 (10) ◽  
pp. 1505-1515 ◽  
Author(s):  
João Orestes Schneider Santos ◽  
Léo Afraneo Hartmann ◽  
Neal Jesse McNaughton ◽  
Robert M Easton ◽  
Ron G Rea ◽  
...  

A sensitive high resolution ion microprobe (SHRIMP) was used in combination with backscattered electron (BSE) and cathodoluminescence (CL) images to determine the age of detrital zircons from sandstones in the Neoproterozoic Middle Run Formation of the eastern Midwest, United States. Eleven samples from seven drill cores of the upper part of the Middle Run Formation contain detrital zircons ranging in age from 1030 to 1982 Ma (84 analyses), with six distinctive modes at 1.96, 1.63, 1.47, 1.34, 1.15, and 1.08 Ga. This indicates that most, but not all, of the zircon at the top of the Middle Run Formation was derived from the Grenville Orogen. The youngest concordant detrital zircon yields a maximum age of 1048 ± 22 Ma for the Middle Run Formation, indicating that the formation is younger than ca. 1026 Ma minus the added extra time needed for later uplift, denudation, thrusting, erosion, and transport to southwestern Ohio. Thus, as judged by proximity, composition, thickness, and geochronology, it is a North American equivalent to other Neoproterozoic Grenvillian-derived basins, such as the Torridon Group of Scotland and the Palmeiral Formation of South America. An alternate possibility, although much less likely in our opinion, is that it could be much younger, any time between 1048 ± 22 Ma and the deposition of the Middle Cambrian Mount Simon Sandstone at about 510 Ma, and still virtually almost all derived from rocks of the Grenville Orogen.


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