scispace - formally typeset
Journal ArticleDOI

Late Paleozoic to Jurassic silicic magmatism at the Gondwana margin: Analogy to the Middle Proterozoic in North America?

TLDR
A vast region of upper Paleozoic to Middle Jurassic (300-150 Ma) silicic magmatic rocks that erupted inboard of the Gondwana margin is a possible Phanerozoic analogue to the extensive Middle Proterozoic (1500-1350 Ma) Silicic province that underlies much of the southern mid-continent of North America as mentioned in this paper.
Abstract
A vast region of upper Paleozoic to Middle Jurassic (300-150 Ma) silicic magmatic rocks that erupted inboard of the Gondwana margin is a possible Phanerozoic analogue to the extensive Middle Proterozoic (1500-1350 Ma) silicic magmatic province that underlies much of the southern mid-continent of North America. Like the North American rocks, the Gondwana silicic magmas appear to be melts of crust that formed about 200-300 m.y. earlier. In the North American case, this older crust formed and was accreted to the continent during a major period of crustal formation (1700-1900 Ma), whereas in the Gondwana case, the crust that melted consisted mainly of magmatic are terranes accreted to the continental margin during the Paleozoic. In both cases, basic to intermediate magmatic rocks are extremely rare and magmatism is less abundant in regions that contain older (and previously melted) crust. The similarities between the North American and Gondwana silicic rocks suggest that both suites formed in extensional settings where basaltic magmas, ponded at the base of the preheated crust, caused extensive crustal melting that inhibited upward passage of the basalts. In both cases, silicic volcanism occurred after major assembly of a supercontinent by subduction and accretion processes, and before breakup of the supercontinent. By analogy with the polar wander curves for Gondwana, the granite-rhyolite provinces may have formed during a period of very slow motion of the supercontinents relative to the poles.

read more

Citations
More filters
Journal ArticleDOI

Tectonic models for accretion of the Central Asian Orogenic Belt

TL;DR: The Central Asian Orogenic Belt ( c. 1000-250 Ma) formed by accretion of island arcs, ophiolites, oceanic islands, seamounts, accretionary wedges, and oceanic plateaux and microcontinents in a manner comparable with that of circum-Pacific Mesozoic-Cenozoic orogens is studied in this article.
Journal ArticleDOI

A Paleo-Mesoproterozoic supercontinent: assembly, growth and breakup

TL;DR: The pre-Rodinia supercontinent was assembled along global-scale 2.1-1.8 Ga collisional orogens and contained almost all of Earth's continental blocks as mentioned in this paper.
Journal ArticleDOI

Linking accretionary orogenesis with supercontinent assembly

TL;DR: The age relations for assembly of Gondwana and Pangea indicate that the timing of collisional orogenesis between amalgamating continental bodies was synchronous with subduction initiation and contractional orogens within accretionary orogens located along the margins of these supercontinents as mentioned in this paper.
Journal ArticleDOI

Andean flat-slab subduction through time

TL;DR: In this article, a wide range of regions throughout the Andes, including the three present flat-slab segments (Pampean, Peruvian, Bucaramanga), three incipient flat-slam segments (Carnegie, Guanacos, Tehuantepec), three older and no longer active Cenozoic flat slabs segments (Altiplano, Puna, Payenia), and an inferred Palaeozoic flatslab segment (Early Permian ‘San Rafael’).
Journal ArticleDOI

Creation and destruction of lower continental crust

TL;DR: The lowermost crust at continent-ocean and continent-continent convergent plate margins is more likely to experience transient overthickening events (compressional orogenies) than is intra-plate crust as discussed by the authors.
Related Papers (5)