Topic
Gondwana
About: Gondwana is a research topic. Over the lifetime, 6078 publications have been published within this topic receiving 263050 citations. The topic is also known as: Gondwanaland.
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TL;DR: In this article, the Pindos ocean, the Antalya ocean, and the Cyprus ocean were investigated and it was shown that, despite some important differences in the timing of events, individual oceanic basins went through essentially predictable stages, including rifting, spreading, subduction/accretion, displacement/emplacement and collision.
371 citations
TL;DR: A detailed case history of the Indian plate tectonic evolution can be found in this paper, where the authors present a case study of the repeated rifting of Indian plate from surrounding Gondwana continents, its northward migration, and its collision first with the Kohistan-Ladakh Arc at the Indus Suture Zone, and then with Tibet at the Shyok-Tsangpo Suture.
371 citations
TL;DR: In this paper, the southern part of the East African-Antarctic orogen can best be reconstructed when a number of microplates (the Falkland, Ellsworth-Haag, and Filchner blocks) are positioned between southern Africa and East Antarctica.
Abstract: The East African–Antarctic orogen is one of the largest orogenic
belts on the planet. It resulted from the collision of various parts of
proto–East and West Gondwana during late Neoproterozoic–early
Paleozoic time (between 650 and 500 Ma). We propose that the
southern part of this Himalayan-type orogen can be interpreted in
terms of a lateral-escape tectonic model. Modern Gondwana reconstructions
show that the southern part of the East African–
Antarctic orogen can best be reassembled when a number of microplates
(the Falkland, Ellsworth-Haag, and Filchner blocks) are
positioned between southern Africa and East Antarctica. This microplate
assemblage is unusual. The microplates probably represent
shear-zone–bounded blocks, produced by tectonic translation
during lateral escape, similar to those currently evolving in Southeast
Asia. One of the escape-related shear zones is exposed as the
20-km-wide Heimefront transpression zone in western Dronning
Maud Land. Coats Land, a crustal block within the orogen, probably
represents a block of older crust that was not subjected to
tectonometamorphic reworking ca. 500 Ma by lateral tectonic escape.
The southern part of the orogen is also typified by very large
volumes of late-tectonic A2-type granitoids, intruded ca. 530–490
Ma, probably as a consequence of delamination of the orogenic
root and the subsequent influx of hot asthenospheric mantle during
tectonic escape. Erosional unroofing of the orogen is documented
by the remnants of originally massive areas covered by Cambrian–
Ordovician molasse-type sedimentary rocks throughout Africa,
Arabia, and Antarctica, testifying to the past extent and size of this
largest of orogens.
369 citations
TL;DR: In this paper, the authors explain the Variscan orogen in a two-plate scenario, reasoning that the complexity of the orogen (multitude of high-grade metamorphic belts, compositional diversity of coeval magmatism, and arrangement of foreland basins) is the result of the distribution of crustal domains of contrasting rheological properties.
368 citations
TL;DR: The first extensive geochronological study of magmatic and metamorphic rocks from central Dronning Maud Land (DML), East Antarctica, is reported in this paper, which indicates that the oldest rocks in central DML are Mesoproterozoic in age.
Abstract: The about 500 km long coastal stretch of central Dronning Maud Land (DML), East Antarctica, is critical for understanding both Gondwana and Rodinia assembly. In common Gondwana reconstructions central DML lies at the potential southern extension of the Mozambique Belt. We report the first extensive geochronological study of magmatic and metamorphic rocks from the area. These new U‐Pb SHRIMP zircon and Sm‐Nd‐data of rocks sampled during the German international GeoMaud 1995/96 expedition indicate that the oldest rocks in central DML are Mesoproterozoic in age. The crystallization ages of metavolcanic rocks were determined at c. 1130 Ma. Syn‐tectonic granite sheets and plutons give ages of c. 1080 Ma, contemporaneous with metamorphic zircon growth at granulite facies conditions. An anorthosite intrusion and a charnockite are dated at c. 600 Ma. Subsequent metamorphism is recorded for at least two different episodes at c. 570–550 Ma and between 530 to 515 Ma. The latter metamorphic event reached granulite fa...
367 citations