Deforming the Earth’s Crust: Faulting Pg. 129

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

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

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,

Mountain Building Occurs because of tectonic plate movement

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

Folded mountain Layers that are squeezed together

Appalachian mountains The Alps Himalayan Mountains What are some examples of folded 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? Uplift—the rising of a region of the Earth’s crust Subsidence—the sinking 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