Deforming the Earth’s Crust: Faulting Pg. 117

What is a FAULT? When rock layers BREAK when stress is applied One block of rock slides relative to another

the foot wall? What is the hanging wall, Narrow base block of angled crust What is the hanging wall, see page 114 Broad base block of angled crust the foot wall?

What is a normal fault? When the hanging wall moves down relative to the footwall Occurs when tectonic forces cause tension that pull the blocks of rock apart

A normal fault

What is a REVERSE FAULT? When the Hanging wall moves up relative to the footwall Occurs when tectonic forces push the blocks of rock together (Compression)

A reverse fault

What are STRIKE-SLIP FAULTS? Form when opposing forces cause rock to break and move horizontally Example: California’s San Andreas fault

A strike slip fault Geologic Activity, http://www.nps.gov/pore/naturescience/geologicactivity.htm

Mountain Building Occurs because of tectonic plate movement

What are folded mountains? Rock layers that are squeezed together Form at convergent plate boundaries Make the highest mountains in the world

Folded mountain Layers that are squeezed together

What are some examples of folded mountains? Appalachian mountains The Alps Himalayan Mountains

What are fault block mountains? Tension causes large blocks of rock to drop down Example: Teton Mountains, Wyoming

Fault block mountains Grand Tetons Wyoming

Volcanic Mountains

What is uplift and subsidence? Subsidence—the sinking of a region of the Earth’s crust Uplift—the rising of a region of the Earth’s crust

What is Tectonic Letdown? Sinking of a region of Earth due to tension Rift zone – a set of deep cracks that form between two plates that are pulling apart

Formation of a Rift Valley Sequence showing how movements deep under the Earth's Crust help to create a Rift Valley