Isotopic contrasts, chronology of elemental transfers and high-grade metamorphism: the Sri Lanka Highland granulites, and the Lewisian (Scotland) and Nuk (SW Greenland) gneisses

1991 ◽  
Vol 80 (2) ◽  
pp. 279-288 ◽  
Author(s):  
T. C. Liew ◽  
C. C. Milisenda ◽  
A. W. Hofmann
Keyword(s):  
Sri Lanka ◽  
High Grade ◽  
Grade Metamorphism ◽  
High Grade Metamorphism

Prolonged Neoproterozoic high‐grade metamorphism of the Wanni Complex, Sri Lanka: New insights from petrology, phase equilibria modelling, and zircon U–Pb geochronology of partially melted cordierite gneiss from Walpita

2020 ◽  
Vol 55 (9) ◽  
pp. 6147-6168 ◽  
Author(s):  
Eri Hirayama ◽  
Toshiaki Tsunogae ◽  
Sanjeewa P. K. Malaviarachchi ◽  
Yusuke Takamura ◽  
Prasanna L. Dharmapriya ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Phase Equilibria ◽  
High Grade ◽  
Grade Metamorphism ◽  
High Grade Metamorphism

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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