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Cratons

Cratons, mobile belts, alkaline rocks and continental ...

Journal of the Geological Society, London, Vol. 150, 1993, pp. 89-98, 8 figs. Printed in Northern Ireland Cratons, mobile belts, alkaline rocks and continental lithospheric mantle: the Pan-African testimony R. BLACK l& J.-P. LIEGEOIS 2 1CNRS, URA 736, Laboratoire de Minkralogie, Muskum National ...

j22 Continental margins, cratons, orogens in terms of

561 LAURENTIA j22 Continental margins, cratons, orogens in terms of plate tectonics < Gk. oro, mountain > Continental margins are of two types: tectonically active (example: Pacific), and passive (examples: Atlantic 1 and Gulf). 2 Convergent and transform fault plate boundaries are "orogenic ...

Chapter2 Cratons of the Indian Shield

Chapter2 Cratons of the Indian Shield 2.1 Introduction The Indianshield is made up of a mosaic of Precambrian metamorphic terrains that exhibit low to high-grade crystalline rocks in the age range of 3.6-2.6 Ga.

The elusive lithosphere–asthenosphere boundary (LAB ...

The elusive lithosphere-asthenosphere boundary (LAB) beneath cratons The elusive lithosphere–asthenosphere boundary (LAB) beneath cratons

Recombining the Fragmented Structure and Memory of Cratons

Recombining the Fragmented Structure and Memory of Cratons Maarten J de Wit, AEON (Africa Earth Observatory Network) University of Cape Town, Rondebosch 7701, South Africa maarten@science. uct.ac.za Large-scale experiments across cratons such as Lithoprobe and the Kaapvaal Seismic Project have ...

4 to 5 54 45 90 Page: 242 Preamble

Although the origin is unclear, most cratons of the world experienced major episodes of metamorphism between _____ billion years ago. A) 2.3 and 2.7 B) 3.3 and 3.5 C) 1.3 and 2.3 D) 2.7 and 3.3 Page: 253 Greenstone Belts 1.

Vaalbara, Earth'soldestassembled continent? A combined ...

The parallel arrangement of lineaments on both cratons and the similar timing and association of pan-cratonic strike-slip faults, arenaceous basin sedimentation, and K-rich gran-iteintrusion, suggests that the two cratons shared a period of stabilization at &3.1-2.7 Ga.

CHAPTER 13 Denudation, weathering and mass wasting

This approach permits the linkage of geomorphic processes with the time scales and global patterns of morphotectonic activity, the tectonic machinery providing initial uplift and a global tectonic framework for the location of orogens, cratons and basins where geomorphic landsystems develop.

Sa˜oLuõ ´sCratonandGurupi Belt (Brazil): possible links ...

These Neoproterozoic belts are part of the branched system of orogens associated with amalgamation of the Amazonian, West Africa -Sa˜oLuõ´s, Sa˜o Francisco and other cratons and minor continental blocks into the West Gondwana supercontinent.

Geochemical/Petrologic Constraints on the Origin of Cratonic ...

of cratons is, in some manner, related to the unique composition and thermal structure of their underlying mantle "keels". Exactly how these variables conspire to ensure craton longevity is not immediately obvious.