scholarly journals Tectonic setting and U-Pb zircon age of the Poulin-de-Courval Mangerite, Saguenay-Lac Saint-Jean area, Grenville Province, Quebec

1998 ◽  
Author(s):  
C Hébert ◽  
O van Breemen ◽  
P Lacoste
Keyword(s):  
Tectonic Setting ◽  
Grenville Province ◽  
Zircon Age

New insights into the geologic evolution of the Grenvillian Trenton Prong inlier, Central Appalachian Piedmont, USA

2020 ◽  
Vol 57 (7) ◽  
pp. 840-854
Author(s):  
Richard A. Volkert
Keyword(s):  
Tectonic Setting ◽  
Hanging Wall ◽  
Sediment Source ◽  
Slow Cooling ◽  
Grenville Province ◽  
Magmatic Arc ◽  
Metamorphic History ◽  
Arc Setting ◽  
Appalachian Piedmont ◽  
Back Arc

New geochemical and 40Ar/39Ar hornblende and biotite data from the Grenvillian Trenton Prong inlier provide the first constraints for the identification of lithotectonic units, their tectonic setting, and their metamorphic to post-metamorphic history. Gneissic tonalite, diorite, and gabbro compose the Colonial Lake Suite magmatic arc that developed along eastern Laurentia prior to 1.2 Ga. Spatially associated low- and high-TiO2 amphibolites were formed from island-arc basalt proximal to the arc front and mid-ocean ridge basalt-like basalt in a back-arc setting, respectively. Supracrustal paragneisses include meta-arkose derived from a continental sediment source of Laurentian affinity and metagraywacke and metapelite from an arc-like sediment source deposited in a back-arc basin, inboard of the Colonial Lake arc. The Assunpink Creek Granite was emplaced post-tectonically as small bodies of peraluminous syenogranite produced through partial melting of a subduction-modified felsic crustal source. Prograde mineral assemblages reached granulite- to amphibolite-facies metamorphic conditions during the Ottawan phase of the Grenvillian Orogeny. Hornblende 40Ar/39Ar ages of 935–923 Ma and a biotite age of 868 Ma record slow cooling in the northern part of the inlier following the metamorphic peak. Elsewhere in the inlier, biotite 40Ar/39Ar ages of 440 Ma and 377–341 Ma record partial to complete thermal resetting or new growth during the Taconian and Acadian orogens. The results of this study are consistent with the Trenton Prong being the down-dropped continuation of the Grenvillian New Jersey Highlands on the hanging wall of a major detachment fault. The Trenton Prong therefore correlates to other central and northern Appalachian Grenvillian inliers and to parts of the Grenville Province proper.

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.

The tectonic setting of the eastern margin of the Sino-Korean Block inferred from detrital zircon U–Pb age and Nd isotope composition of the Pyeongan Supergroup (upper Palaeozoic – Lower Triassic), Korea

2017 ◽  
Vol 156 (3) ◽  
pp. 471-484 ◽  
Author(s):  
MUN GI KIM ◽  
YONG IL LEE ◽  
TAEJIN CHOI ◽  
YUJI ORIHASHI
Keyword(s):  
Detrital Zircon ◽  
Isotope Composition ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Lower Triassic ◽  
Zircon Age ◽  
Nd Isotope ◽  
Eastern Margin ◽  
Late Palaeozoic ◽  
Nd Isotope Composition

AbstractThe upper Palaeozoic succession (Pyeongan Supergroup) in central eastern Korea is well correlated with the equivalent successions distributed in North China, suggestive of the Korean upper Palaeozoic being part of the Sino-Korean Block. Detrital zircon U–Pb ages and Sm–Nd isotope compositions of the Pyeongan Supergroup in the Samcheok coalfield of the Taebaeksan Basin were analysed. A single predominant zircon age peak at c. 1.9 Ga (> 70%) is marked in all sedimentary units, followed by varying amounts of minor late Palaeozoic grains (up to 30%). The rarity of Meso- to Neoproterozoic- and Silurian-aged zircons confirms that sediment influx from the South China and Qinling blocks was insignificant. The 2.0–1.8 Ga-dominated zircon age pattern and the Nd isotope composition (average εNd(0) = −15.5±4.0) of the Pyeongan Supergroup most closely reflect the signature of the Yeongnam Massif basements, which supports a previous hypothesis that the Pyeongan Supergroup was mostly derived from a palaeo-orogen located to the east–southeast. Relatively higher εNd(0) values (> −10.1) in the lowermost and the upper parts of the succession are closely matched by the increased occurrence of syn-depositional-aged zircons, which indicates considerable mixing of juvenile materials at c. 320 Ma and 260 Ma. Both arc-related magmatic events are interpreted to have been related to oceanic subduction, suggesting that the eastern margin of the Sino-Korean Block was an active continental margin during late Palaeozoic times.

Mafic and ultrapotassic rocks from the Canyon domain (central Grenville Province): geochemistry and tectonic implications

2012 ◽  
Vol 49 (2) ◽  
pp. 412-433 ◽  
Author(s):  
Carolina Valverde Cardenas ◽  
Aphrodite Indares ◽  
George Jenner
Keyword(s):  
Tectonic Setting ◽  
Source Region ◽  
Crustal Contamination ◽  
Granulite Facies ◽  
Grenville Province ◽  
Mafic Rocks ◽  
Isotopic Signatures ◽  
Late Evolution ◽  
Grenvillian Orogeny ◽  
Laurentian Margin

The Canyon domain and the Banded complex in the Manicouagan area of the Grenville Province preserve a record of magmatic activity from ∼1.4 to 1 Ga. This study focuses on 1.4–1.2 Ga mafic rocks and 1 Ga ultrapotassic dykes. Geochemistry and Sm–Nd isotopic signatures were used to constrain the origin of these rocks and evaluate the changing role of the mantle with time and tectonic setting from the late evolution of the Laurentian margin to the Grenvillian orogeny, in the Manicouagan area. The mafic rocks include layers inferred to represent flows, homogeneous bodies in mafic migmatite, and deformed dykes, all of which were recrystallized under granulite-facies conditions during the Grenvillian orogeny. In spite of the complexities inherent in these deformed and metamorphosed mafic rocks, we were able to recognize suites with distinctive geochemical and isotopic signatures. Integration of this data along with available ages is consistent with a 1.4 Ga continental arc cut by 1.2 Ga non-arc basalts derived from depleted asthenospheric mantle, with varied degrees of crustal contamination and inferred to represent magmatism in an extensional environment. The 1 Ga ultrapotassic dykes postdate the Grenvillian metamorphism. They are extremely enriched in incompatible elements, have negative Nb anomalies, relatively unradiogenic Sr-isotopic compositions (initial 87Sr/86Sr ~ 0.7040) and εNd –3 to –15. Some dykes have compositional characteristics consistent with derivation from the mantle, ruling out crustal contamination as a major process in their petrogenesis. The most likely source region for the ultrapotassic dykes is a metasomatized subcontinental lithospheric mantle, with thermal input from the asthenosphere in association with post-orogenic delamination.

scholarly journals Granitoid plutons in peri-Gondwanaan terranes of Cape Breton Island, Nova Scotia, Canada: new U-Pb (zircon) age constraints

2018 ◽  
pp. 021-080 ◽  
Author(s):  
Sandra M. Barr ◽  
Deanne Van Rooyen ◽  
Chris E. White
Keyword(s):  
Tectonic Setting ◽  
Magmatic Activity ◽  
Zircon Age ◽  
Cape Breton Island ◽  
The Past ◽  
Late Cambrian ◽  
Cape Breton ◽  
History Of ◽  
Tectonic Settings ◽  
Age Constraints

Granitoid plutons are a major component of pre-Carboniferous rocks in Cape Breton Island and knowledge of the time and tectonic setting of their emplacement is crucial for understanding the geological history of the island, guiding exploration for granite-related economic mineralization, and making along-orogen correlations. The distribution of these plutons and their petrological characteristics have been used in the past for recognizing both Laurentian and peri-Gondwanan components in Cape Breton Island, and for subdividing the peri-Gondwanan components into Ganderian and Avalonian terranes. However, ages of many plutons were assumed on the basis of field relations and petrological features compared to those of the relatively few reliably dated plutons. Seventeen new U–Pb (zircon) ages from igneous units reported here provide enhanced understanding of the distribution of pluton ages. Arc-related plutons in the Aspy terrane with ages of ca. 490 to 475 Ma likely record the Penobscottian tectonomagmatic event recognized in the Exploits subzone of central Newfoundland and New Brunswick but not previously recognized in Cape Breton Island. Arc-related Devonian plutonic activity in the same terrane is more widespread, continuous, and protracted (445 Ma to 395 Ma) than previously known. Late Devonian magmatism in the Ganderian Aspy terrane is similar in age to that in the Avalonian Mira terrane (380 to 360 Ma) but the tectonic settings are different. In contrast, magmatic activity in the Bras d’Or terrane is almost exclusively arc-related in the Late Ediacaran (580 to 540 Ma) and rift-related in the Late Cambrian (520 to 490 Ma). The new data support the terrane distinctions previously documented.

scholarly journals Relationships between Alluvial Facies/Depositional Environments, Detrital Zircon U-Pb Geochronology, and Bulk-Rock Geochemistry in the Cretaceous Neungju Basin (Southwest Korea)

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1023
Author(s):  
Hyojong Lee ◽  
Min Gyu Kwon ◽  
Seungwon Shin ◽  
Hyeongseong Cho ◽  
Jong-Sun Kim ◽  
...  
Keyword(s):  
Continental Margin ◽  
Detrital Zircon ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Depositional Environments ◽  
Source Rocks ◽  
Bulk Rock ◽  
Zircon Age ◽  
Margin Setting ◽  
Weathering Intensity

Zircon U-Pb geochronology and bulk-rock geochemistry analyses were carried out to investigate their relationship with depositional environments of the non-marine Neungju Basin sediments in South Korea. The Neungju Basin was formed in an active continental margin setting during the Late Cretaceous with associated volcanism. Detrital zircon age distributions of the Neungju Basin reveal that the source rocks surrounding the basin supplied sediments into the basin from all directions, making different zircon age populations according to the depositional environments. Mudstone geochemistry with support of detrital zircon U-Pb age data reveals how the heterogeneity affects the geochemical characteristics of tectonic setting and weathering intensity. The sediments in the proximal (alluvial fan to sandflat) and distal (playa lake) environments differ compositionally because sediment mixing occurred exclusively in the distal environment. The proximal deposits show a passive margin signature, reflecting their derivation from the adjacent metamorphic and granitic basement rocks. The distal deposits properly indicate an active continental margin setting due to the additional supply of reworked volcaniclastic sediments. The proximal deposits indicate a minor degree of chemical weathering corresponding to fossil and sedimentological records of the basin, whereas the distal deposits show lower weathering intensity by reworking of unaltered volcaniclastic detritus from unstable volcanic and volcaniclastic terranes. Overall, this study highlights that compositional data obtained from a specific location and depositional environments may not describe the overall characteristic of the basin.

Geochemistry and U–Pb zircon age of the Paleoproterozoic metasedimentary rocks from the Bidou I, Nyong Series, Cameroon: Implications for provenance and tectonic setting

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Brice Kamguia Woguia ◽  
Gus Djibril Kouankap Nono ◽  
Philomène Estelle Nga Essomba Tsoungui ◽  
Evine Laure Tanko Njiosseu ◽  
Patrick Ayonta Kenne ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Zircon Age ◽  
Metasedimentary Rocks
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