Extensional tectonics

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Extensional tectonics is concerned with the structures formed, and the tectonic processes associated with, the stretching of the crust or lithosphere.

Areas of extensional tectonics are typically associated with:

• The development of continental rifts, with or without the effects of mantle upwelling
• The gravitational spreading of zones of thickened crust formed during continent-continent collision
• Tensional flexures along strike-slip faults
• On passive margins where an effective basal detachment layer is present at the upper end of a linked system

[edit] Extensional structures

The main structures formed in areas of extensional tectonics are normal faults and graben structures.

Prominent examples include:

• The Great Rift Valley of east Africa
• The Basin and Range province of western North America
• The global mid-ocean ridge system
• The Dead Sea basin