GEOL100
3-31-08
Continental deformation II

Continental - Continental convergences: :


Himalayas, Mt. Everest in center, from Wikipedia

Now imagine we take the situation described, and slam a continent into it.

In ancient rocks, we recognize continent - continent convergences through parallel juxtaposed volcanic-magmatic belts, suture zones, and fold and thrust belts with the occasional ophiolite. Ancient examples include the Urals, Appalachians, Atlas Mts.

6. Transform boundaries:

7. Microplate terranes: Continental margins often include remnants of continental or island arc crust that are substantially different from surrounding rock. Thought to be results of continental collisions with small continents and arcs that were not big enough to shut down subduction. Indeed, much of western North America is an incompletely sutured moasic of microplates.

Regional tectonic structures:

Interior rocks - Cratons: Thick, extensive, topographically flat, tectonically stable interiors of continents whose basement rocks are old (typically Archean or early Proterozoic) and crystalline (metamorphic and igneous).