Lecture 15 - GEOS 1004, SPOTILA Lecture 15, 10/22/09 PLATE...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
GEOS 1004, SPOTILA Lecture 15, 10/22/09 PLATE TECTONIC BOUNDARIES D. Collisional plate boundaries, mountain belts Subduction ends when the oceanic plate is gone; what then? Continents don't subduct. -collision, between the continents or the continent and the volcanic arc that was above the subduction -creates mountain belts (also called orogenic belts; mountain building is orogeny ) Active continent collision? - India colliding with Asia (creating Himalayas) How is space made for 2 colliding continental plates? (they don’t subduct; they can’t occupy the same space) 1) fold and thrust belt (one mass of rock is stacking up on top of another) Thrust faults push one group of rock over another - this thickens the crust. Rocks are folded in between the thrust faults. Increasing the thickness of the crust increases elevation, grows mountains. Isostasy. -1 km gain in elevation for every 5 km extra thickness of crust. The 5 km Tibetan plateau is there because the crust is twice as thick (70 km) as usual. 2) strike-slip faulting; lateral motion of microplates out of the way of the colliding continent.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/11/2011 for the course GEOG 1004 at Virginia Tech.

Page1 / 3

Lecture 15 - GEOS 1004, SPOTILA Lecture 15, 10/22/09 PLATE...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online