U–Pb LA-ICP-MS detrital zircon ages from the Cambrian of Al Qarqaf Arch, central-western Libya: Provenance of the West Gondwanan sand sea at the dawn of the early Palaeozoic

2013 ◽  
Vol 79 ◽  
pp. 74-97 ◽  
Author(s):  
Muftah Mahmud Altumi ◽  
Olaf Elicki ◽  
Ulf Linnemann ◽  
Mandy Hofmann ◽  
Anja Sagawe ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
The West ◽  
Icp Ms ◽  
Early Palaeozoic ◽  
Detrital Zircon Ages

scholarly journals IDADE MÁXIMA DE SEDIMENTAÇÃO E PROVENIÊNCIA DO COMPLEXO JEQUITINHONHA NA ÁREA-TIPO (ORÓGENO ARAÇUAÍ): PRIMEIROS DADOS U-PB (LA-ICP-MS) DE GRÃOS DETRÍTICOS DE ZIRCÃO

2013 ◽  
Author(s):  
Tatiana Gonçalves-Dias ◽  
Antônio Carlos Pedrosa-Soares ◽  
Ivo Antônio Dussin ◽  
Fernando Flecha de Alkmim ◽  
Fabrício Andrade Caxito ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Passive Margin ◽  
Rift System ◽  
Sediment Sources ◽  
Chapada Diamantina ◽  
Mean Values ◽  
Type Area ◽  
Icp Ms ◽  
Detrital Zircon Ages ◽  
Araçuaí Orogen

O Complexo Jequitinhonha, situado no nordeste de Minas Gerais, é uma das unidades metassedimentares mais extensas do Orógeno Araçuaí. Na área-tipo, situada na região de Jequitinhonha -Almenara, este complexo consiste de paragnaisse peraluminoso (kinzigítico) migmatizado, com intercalações de quartzito, grafita gnaisse e rocha calcissilicática. Os dados isotópicos U-Pb (LA-ICP-MS) de 80 grãos detríticos de zircão de uma amostra de quartzito, coletada em corte da BR-367 cerca de 12 km a SW de Almenara, permitem identificar seis principais intervalos de idades, cujas médias das modas sugerem as seguintes fontes de sedimentos: o embasamento São Francisco-Congo (2541 ± 8 Ma e 2044 ± 6 Ma), o sistema Espinhaço-Chapada Diamantina (1819 ± 6 Ma, 1487 ± 5 Ma e 1219 ± 3 Ma) e o sistema de rifteamento Noqui-Zadiniano-Mayumbiano-Salto da Divisa (956 ± 4 Ma). A idade máxima de sedimentação em 898 ± 8 Ma é dada pelo zircão mais novo. Os espectros de idades desta amostra do Complexo Jequitinhonha e de rochas do Grupo Macaúbas são muito similares, indicando correlação entre estas unidades. Contudo, no Complexo Jequitinhonha inexiste evidência de glaciação. Assim, o Complexo Jequitinhonha na área-tipo é interpretado como depósito de margem passiva da bacia precursora do Orógeno Araçuaí, mais novo que a glaciação Macaúbas e, portanto, equivalente às formações Chapada Acauã Superior e Ribeirão da Folha.Palavras-chave: Complexo Jequitinhonha, geocronologia U-Pb, Orógeno AraçuaíABSTRACT: MAXIMUM SEDIMENTATION AGE AND PROVENANCE OF THE JEQUITINHONHA COMPLEX IN THE TYPE-AREA (ARAÇUAÍ OROGEN): FIRST U-PB (LA-ICP-MS) DATA FROM DETRITAL ZIRCON GRAINS.The Jequitinhonha Complex is one of the most extensive metasedimentary units of the Araçuaí Orogen. In the type-area, located in the Jequitinhonha-Almenara region, this complex includes migmatized peraluminous (kinzigitic) paragneiss with intercalations of quartzite, graphite gneiss and calcsilicate rock. U-Pb (LA-ICP-MS) data from 80 detrital zircon grains extracted from a quartzite sample, collected in a BR-367 road cut around 12 km SW from Almenara, yielded six main age intervals, which mode mean values suggest the following sediment sources: the São Francisco-Congo basement (2541 ± 8 Ma and 2044 ± 6 Ma), the Espinhaço-Chapada Diamantina system (1819 ± 6 Ma, 1487 ± 5 Ma and 1219 ± 3 Ma), and the Noqui-Zadinian-Mayumbian-Salto da Divisa rift system (956 ± 4 Ma). The maximum sedimentation age of 898 ± 8 Ma is constrained by the youngest zircon grain. Spectra of detrital zircon ages for this sample of the Jequitinhonha Complex and rocks of the Macaúbas Group are very similar and suggest a correlation between these units. However, this complex shows no evidence of glaciation. Therefore, the Jequitinhonha Complex in its type-area is interpreted as a passive margin deposit of the precursor basin of the Araçuaí Orogen, younger than the Macaúbas glaciation and, thus, equivalent of the Upper Chapada Acauã and Ribeirão da Folha formations.Keywords: Jequitinhonha Complex, U-Pb geochronology, Araçuaí Orogen

Detrital zircon sources in the Ordovician metasedimentary rocks of the Moroccan Meseta: Inferences for northern Gondwanan passive-margin paleogeography

2022 ◽  
Author(s):  
Cristina Accotto ◽  
David Martínez Poyatos ◽  
Antonio Azor ◽  
Cristina Talavera ◽  
Noreen Joyce Evans ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
West African ◽  
Passive Margin ◽  
Variscan Orogeny ◽  
The West ◽  
West African Craton ◽  
Metasedimentary Rocks ◽  
Population Peak ◽  
A Minor ◽  
Detrital Zircon Ages

ABSTRACT Detrital zircon U-Pb geochronology has been widely used to constrain the pre-Carboniferous geography of the European and, to a lesser extent, the Moroccan Variscides. The latter have been generally considered as part of a long-lasting passive margin that characterized northern Gondwana from Ordovician to Devonian time, and was subsequently involved in the late Paleozoic Variscan orogeny. We report detrital zircon ages for three Early to Late Ordovician samples from the Beni Mellala inlier in the northeastern part of the Western Moroccan Meseta in order to discuss the temporal evolution of the sources of sediments in this region. The detrital zircon spectra of these samples, characterized by two main populations with mean ages of 630–610 Ma and 2170–2060 Ma, are typical of Cambrian–Devonian rocks from the Moroccan Variscides and confirm their link to the West African craton. A minor Stenian–Tonian population (peak at ca. 970 Ma) suggests the influence of a distant and intermittent NE African source (Sahara metacraton), which was probably interrupted after Ordovician time. Our data support previous interpretations of the Moroccan Meseta (and the entire northern Moroccan Variscides) as part of the northern Gondwana passive margin. The main sources of these sediments would have been the West African craton in the western regions of the passive margin (Moroc- can Meseta and central European Paleozoic massifs), and the Arabian-Nubian Shield and/or Sahara metacraton in the eastern areas (Libya, Egypt, Jordan, central and NW Iberian zones during Paleozoic time), where the 1.0 Ga detrital zircon population is persistent throughout the Ordovician–Devonian time span.

scholarly journals New ideas on the Proterozoic-Early Palaeozoic evolution of NW Iberia: insights from U–Pb detrital zircon ages

2000 ◽  
Vol 102 (3-4) ◽  
pp. 185-206 ◽  
Author(s):  
J. Fernández-Suárez ◽  
G. Gutiérrez-Alonso ◽  
G.A. Jenner ◽  
M.N. Tubrett
Keyword(s):  
Detrital Zircon ◽  
Nw Iberia ◽  
New Ideas ◽  
Early Palaeozoic ◽  
Detrital Zircon Ages

Provenance of Carboniferous sandstones in the central and southern parts of the Pennine Basin, UK: evidence from detrital zircon ages

2020 ◽  
pp. pygs2020-010
Author(s):  
A.C. Morton ◽  
J.I. Chisholm ◽  
D. Frei
Keyword(s):  
Detrital Zircon ◽  
Local Source ◽  
The West ◽  
Content Type ◽  
North West ◽  
Source Areas ◽  
The North ◽  
Isotopic Analyses ◽  
Supplementary Material ◽  
Detrital Zircon Ages

New U-Pb isotopic analyses of detrital zircon grains from Namurian and Westphalian sandstones in the central and south parts of the Pennine Basin are combined with published analyses from the same region, to assess existing views on the nature and location of the source areas that supplied the clastic sediment. The study confirms that most sandstones were derived from distant areas to the north, west and south, and that a local source, in the Wales-Brabant High, also supplied sediment at times. The northern sources are thought to lie mainly in Laurentia (East Greenland), with some input from Baltica (Norway). Most sandstones entering from the west are thought to have been supplied from areas of Avalonian basement, with some components recycled from sediments that were themselves derived from the Caledonian belt that lay to the north. An exception is the Clifton Rock: its source is thought to lie entirely in the Irish Caledonides or in southern Scotland. Sandstones supplied from the south contain significant numbers of late Devonian and Carboniferous grains, indicating the inclusion of material eroded from the active Variscan orogenic belt in Europe. Northern provenance prevailed during Namurian and early Langsettian times, then alternated with western supply until the late Langsettian. Western input then dominated through most of Duckmantian times, until superseded in the late Duckmantian by supply from the Variscan orogen. The Woolley Edge Rock, now shown to be an isolated member of the northern group, entered the area just before the earliest sandstone of Variscan origin.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5174702

U–Pb detrital zircon ages from Gorgoglione Flysch sandstones in Southern Apennines (Italy) as provenance indicators

2020 ◽  
pp. 1-16 ◽  
Author(s):  
Annamaria Fornelli ◽  
Salvatore Gallicchio ◽  
Francesca Micheletti ◽  
Antonio Langone
Keyword(s):  
Detrital Zircon ◽  
Mediterranean Area ◽  
Source Rocks ◽  
Southern Apennines ◽  
Fine Grained ◽  
Icp Ms ◽  
History Of ◽  
The Mediterranean ◽  
Intermediate Part ◽  
Detrital Zircon Ages

Abstract Twenty-one sandstone samples belonging to the intermediate part of Gorgoglione Flysch (GF) dated Middle-Miocene, cropping out in the Southern Apennines (Italy), have been studied to highlight the detritus provenance. Petrographic and chemical composition indicates that the successions consist of feldspatho-quartzose and litho-feldspatho-quartzose arenites interbedded with pelitic and calciclastic layers and reveals a provenance from a basement formed by low- to medium-grade metamorphic rocks with abundant granitoids covered by sedimentary rocks in which a volcanic component was also present. In the Mediterranean area, basements with these characteristics are widespread both in western and southwestern domains. The supply provenance of Gorgoglione Flysch has been better detailed utilizing U–Pb detrital zircon ages recording the geological history of the source rocks. Fifty-eight crystals from six samples of coarse- and fine-grained sandstones have been analysed using the U–Pb isotopic systematic (LA-ICP-MS). They produce 70 concordant zircon ages forming three defined clusters at 672 ± 28 Ma, 458 ± 9 Ma and 297 ± 8 Ma, and four zircon ages corresponding to 24 ± 1 Ma. An evaluation of the entire collected data suggests that the provenance area is better identified in northwestern sectors of the Mediterranean area in which the Sardinia–Corsica (pro-part) block plays a fundamental role.

scholarly journals Chronostratigraphic framework and provenance of the Ossa-Morena Zone Carboniferous basins (SW Iberia)

2020 ◽  
Author(s):  
M. Francisco Pereira ◽  
Cristina Gama ◽  
Ícaro Dias da Silva ◽  
José B. Silva ◽  
Mandy Hofmann ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Volcanic Rocks ◽  
Early Carboniferous ◽  
Suture Zone ◽  
Magmatic Rocks ◽  
Icp Ms ◽  
Minimum Age ◽  
Depositional Age ◽  
Siliciclastic Rocks ◽  
Detrital Zircon Ages

Abstract. Carboniferous siliciclastic and silicic magmatic rocks from the Santa Susana-São Cristovão region contain valuable information regarding the timing of synorogenic processes in SW Iberia. In this region of the Ossa-Morena Zone (OMZ), Late Carboniferous terrigenous strata (i.e. the Santa Susana Formation) unconformably overlie Early Carboniferous marine siliciclastic deposits alternating with volcanic rocks (i.e. the Toca da Moura volcano-sedimentary complex). Lying below this intra-Carboniferous unconformity, the Toca da Moura volcano-sedimentary complex is intruded and overlain by the Baleizão porphyry. Original SHRIMP and LA-ICP-MS U-Pb zircon are presented in this paper, providing chronostratigraphic and provenance constraints, since available geochronological information is scarce and only biostratigraphic ages are currently available for the Santa Susana-São Cristovão region. Our findings and the currently-available detrital zircon ages from Paleozoic terranes of SW Iberia (Pulo do Lobo Zone- PLZ, South-Portuguese Zone- SPZ, and OMZ), were jointly analyzed using the K-S test and MDS diagrams to investigate provenance. The marine deposition is constrained to the age interval of c. 335–331 Ma (Visean) by new U-Pb data for silicic tuffs from the Toca da Moura volcano-sedimentary complex. The Baleizão porphyry, intrusive in the Toca da Moura volcano-sedimentary complex, yielded a crystallization age of c. 317 Ma (Bashkirian), providing the minimum age for the overlying intra-Carboniferous unconformity. A comparison of detrital zircon populations from siliciclastic rocks of the Cabrela and Toca de Moura volcano-sedimentary complexes of the OMZ suggests that they derived from distinct sources more closely associated with the SPZ and PLZ than the OMZ. Above the intra-Carboniferous unconformity, the Santa Susana Formation is either the result of the recycling of distinct sources located in the Laurussian-side (SPZ and PLZ) and Gondwanan-side (OMZ) of the Rheic suture zone. The best estimate of the crystallization age of a granite cobble found in a conglomerate from the Santa Susana Formation yielded c. 303 Ma (Kasimovian-Gzhelian), representing the maximum depositional age for the terrestrial strata. The intra-Carboniferous unconformity seems to represent a stratigraphic gap of approximately 12–14 Ma, providing evidence of the rapid post-accretion/collision uplift of the Variscan orogenic belt in SW Iberia (i.e. the OMZ, PLZ and SPZ).

Detrital zircon ages from the islands of Inousses and Psara, Aegean Sea, Greece: constraints on depositional age and provenance

2008 ◽  
Vol 145 (6) ◽  
pp. 886-891 ◽  
Author(s):  
GUIDO MEINHOLD ◽  
DIRK FREI
Keyword(s):  
Age Groups ◽  
Aegean Sea ◽  
Detrital Zircons ◽  
Age Group ◽  
Icp Ms ◽  
Eastern Aegean ◽  
Depositional Age ◽  
Late Neoproterozoic ◽  
Early Palaeozoic ◽  
Detrital Zircon Ages

AbstractU–Pb LA–SF–ICP–MS analyses of detrital zircons from a metalitharenite on Inousses Island, Greece, gave major age groups of 310–350, 450–500, 550–700, 900–1050 and 1880–2040 Ma and minor peaks between 2600 and 2800 Ma. The youngest concordant zircon grains of 310–330 Ma indicate the maximum age of deposition to be Late Carboniferous, rather than Ordovician, as had been earlier assumed. The lack of zircon ages between 1.1 and 1.8 Ga, coupled with the occurrence ofc.2-Ga-old zircons, imply a northern Gondwana-derived source. Detrital zircons from a garnet–mica schist on Psara Island yielded a major age group ofc.295–325 Ma and only minor Early Palaeozoic and Late Neoproterozoic ages. The youngest grains around 270 Ma indicate the maximum age of deposition to be Late Permian. The Early Palaeozoic ages support a source from terranes at the southern margin of Laurussia during the Late Palaeozoic and hence clarify the palaeotectonic position of units from the eastern Aegean Sea within the Palaeotethyan realm.

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