Petrology and geochronology of metamorphic rocks from the Bossangoa-Bossembélé area, Northern Central African Republic—evidence for Palaeoproterozoic high-grade metamorphism in the North Equatorial Fold Belt

2021 ◽  
Vol 14 (16) ◽  
Author(s):  
Evine Laure Tanko Njiosseu ◽  
Prince Emilien Danguene ◽  
Timoleon Ngnotue ◽  
Sylvestre Ganno ◽  
Gus Djibril Kouankap Nono ◽  
...  
Keyword(s):  
Central African Republic ◽  
Metamorphic Rocks ◽  
High Grade ◽  
Fold Belt ◽  
Grade Metamorphism ◽  
The North ◽  
High Grade Metamorphism

U-Pb ages of plutonism, sedimentation, and metamorphism of the Paleoproterozoic Kisseynew metasedimentary belt, Trans-Hudson Orogen (Manitoba, Canada)

1999 ◽  
Vol 36 (11) ◽  
pp. 1829-1842 ◽  
Author(s):  
N Machado ◽  
H Zwanzig ◽  
M Parent
Keyword(s):  
Ocean Floor ◽  
Arc Magmatism ◽  
High Grade ◽  
Plate Convergence ◽  
Grade Metamorphism ◽  
The North ◽  
Continental Arc ◽  
High Grade Metamorphism ◽  
Flin Flon ◽  
Uplift And Erosion

The Kisseynew Domain is a metasedimentary belt in the central Reindeer Zone of the Trans-Hudson Orogen. It is bounded by 1.92-1.86 Ga volcanic-plutonic belts to the north and south, by an Archean terrane to the east (Superior Province), and by a volcanic-plutonic terrane underlain by an Archean terrane to the southwest (Glennie Domain). The Kisseynew Domain developed in an arc-related setting in the final stages of plate convergence involving the northward migration of arc-ocean floor complexes toward the Archean Hearne Craton. Terminal collision, involving also the Superior Craton, originated multiple fold-thrust systems and high-grade metamorphism. U-Pb ages of 1874-1860 Ma for pretectonic plutonic units in southern Kisseynew Domain are identical to ages of plutonism intruding the arc-ocean floor accretionary complex in the Flin Flon domain (Amisk collage) and indicate its northern extension. Deposition of the Burntwood Group turbidites started at ca. 1860 Ma, indicating uplift and erosion of the volcanic complexes and was coeval with arc magmatism that succeeded the Amisk collage. From 1848 Ma, Burntwood sedimentation was coeval with deposition of Missi Group continental sediments, with continental arc magmatism and early deformation. New and published ages for detrital zircon indicate that sediments were derived both from local 1.89-1.84 Ga units and also from 2.55-2.36 Ga sources. The latter suggest that a Neoarchean-Paleoproterozoic cratonic block was undergoing erosion, remnants of which occur in the Flin Flon Belt. Basin closure started after 1823 Ma and is marked by regional high-grade metamorphism lasting for ca. 30 million years from 1818 Ma to 1785 Ma; late- to posttectonic metamorphic activity lasted until ca. 1775 Ma.

scholarly journals Rb/Sr whole rock isochron age determinations on metamorphosed acid volcanic rocks and granitic gneisses from the Ketilidian mobile belt, South-East Greenland

1974 ◽  
Vol 66 ◽  
pp. 12-20
Author(s):  
S Pedersen ◽  
O Larsen ◽  
D Bridgwater ◽  
J Watterson
Keyword(s):  
Volcanic Rocks ◽  
Mobile Belt ◽  
High Grade ◽  
East Greenland ◽  
Volcanic Material ◽  
Grade Metamorphism ◽  
The North ◽  
Acid Volcanic ◽  
High Grade Metamorphism ◽  
Age Determinations

The metamorphosed supracrustal rocks and paragneisses studied were collected during a reconnaissance traverse across the trend of the Ketilidian mobile belt in South-Bast Greenland (Andrews et al., 1971, 1973). All the samples are taken from gneisses regarded as derived from supracrustal material which was originally composed of acid volcanic material deposited as lavas, ignimbrites or sediments with a large volcanic component. Sample localities are shown in fig. 2. All the rocks have been affected by at least one metamorphic episode during the formation of the Ketilidian mobile belt. All are regarded as deposited after the end of regional high grade metamorphism in the Archaean block to the north (which has yielded a U/Pb zircon diffusion age of 2808 m.y.) and are intruded by a variety of synto late tectonic granites within the Ketilidian mobile belt which have yielded U/Pb diffusion and concordia ages between 1850 and 1770 m.y. in this area (Gulson & Krogh, 1972).

Early Tertiary resetting of potassium–argon dates in the Kootenay Arc, southeastern British Columbia

1983 ◽  
Vol 20 (5) ◽  
pp. 867-872 ◽  
Author(s):  
W. H. Mathews
Keyword(s):  
British Columbia ◽  
Upper Mantle ◽  
Metamorphic Rocks ◽  
High Grade ◽  
Thermal Event ◽  
Grade Metamorphism ◽  
Early Tertiary ◽  
Common Control ◽  
High Grade Metamorphism

K–Ar analyses of rocks in the central Kootenay Arc indicate a Paleocene (or slightly earlier) thermal event, locally reaching 350 °C, that has reset this isotope clock. The area of resetting is nearly coincident with a north–south belt, 20 km wide, of metamorphic rocks resulting from an earlier (mid-Jurassic?) thermal event with temperatures reaching an estimated 625 °C. The strata involved in both high-grade metamorphism and resetting seem not to have been uplifted more than older weakly metamorphosed strata to the east. The mid-Jurassic? and Paleocene thermal events appear to be distinct in time from one another, but may both be related to some common control in the deeper crust or upper mantle.

Neoproterozoic extension in the Greater Dharwar Craton: a reevaluation of the “Betsimisaraka suture” in MadagascarThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.

2011 ◽  
Vol 48 (2) ◽  
pp. 389-417 ◽  
Author(s):  
R. D. Tucker ◽  
J.-Y. Roig ◽  
C. Delor ◽  
Y. Amelin ◽  
P. Goncalves ◽  
...  
Keyword(s):  
Dharwar Craton ◽  
High Grade ◽  
Grade Metamorphism ◽  
Continental Extension ◽  
Shrimp Geochronology ◽  
Igneous Activity ◽  
High Grade Metamorphism ◽  
Local Inversion ◽  
Metaigneous Rocks ◽  
Eastern Domain

The Precambrian shield of Madagascar is reevaluated with recently compiled geological data and new U–Pb sensitive high-resolution ion microprobe (SHRIMP) geochronology. Two Archean domains are recognized: the eastern Antongil–Masora domain and the central Antananarivo domain, the latter with distinctive belts of metamafic gneiss and schist (Tsaratanana Complex). In the eastern domain, the period of early crust formation is extended to the Paleo–Mesoarchean (3.32–3.15 Ga) and a supracrustal sequence (Fenerivo Group), deposited at 3.18 Ga and metamorphosed at 2.55 Ga, is identified. In the central domain, a Neoarchean period of high-grade metamorphism and anatexis that affected both felsic (Betsiboka Suite) and mafic gneisses (Tsaratanana Complex) is documented. We propose, therefore, that the Antananarivo domain was amalgamated within the Greater Dharwar Craton (India + Madagascar) by a Neoarchean accretion event (2.55–2.48 Ga), involving emplacement of juvenile igneous rocks, high-grade metamorphism, and the juxtaposition of disparate belts of mafic gneiss and schist (metagreenstones). The concept of the “Betsimisaraka suture” is dispelled and the zone is redefined as a domain of Neoproterozoic metasedimentary (Manampotsy Group) and metaigneous rocks (Itsindro–Imorona Suite) formed during a period of continental extension and intrusive igneous activity between 840 and 760 Ma. Younger orogenic convergence (560–520 Ma) resulted in east-directed overthrusting throughout south Madagascar and steepening with local inversion of the domain in central Madagascar. Along part of its length, the Manampotsy Group covers the boundary between the eastern and central Archean domains and is overprinted by the Angavo–Ifanadiana high-strain zone that served as a zone of crustal weakness throughout Cretaceous to Recent times.

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