Monday 12/7 Warm Up: 2.4 – Ngorongoro Crater Check Ch 11 HW – How the quizzes are made… Quiz: Unit 4 HW Qz 1 (Ch 11) – Write your answers on the quizzes – Turn in the questions to the row folders – Scan your gradecam sheets Notes: Types of Faults Finish Types of Faults assignment – self-check HW: Current Events – Due Friday!
Mountain Building
There are three main ways to make a mountain: 1) compression force – collision boundary Examples: Himalayas, Appalachians
There are three main ways to make a mountain: 2) tension stress – Fault-block mountains Examples: Sierra Nevada (CA), Grand Tetons (WY)
There are three main ways to make a mountain: 3) volcanoes – divergent boundary – subduction boundary – hot spots New Island Forms Examples: Cascades, Andes volcanic mountains trench Rift valley Example: Hawaii Examples: Iceland, East African Rift
Plate Tectonics Review: Look for Mountains Forming in all 3 ways… Wilson Cycle -
Most mountains are along continental margins continental margin – boundary between continental and ocean crust
– active margin – along a plate boundary (YES – mtn. building) – passive margin – not along a plate boundary (NO – mtn. building) Passive East Coast US Active West Coast US
What forces and faults are involved in mountain building? Compression Shear Stress Tension SqueezingSliding PastPulling Apart
3 types of stress: 1) compression – push together (like a convergent boundary) Compression Squeezing
3 types of stress: 2) tension – pull apart (like a divergent boundary) Tension Pulling Apart
3 types of stress: 3) shear – pushed in two, opposite directions (like a transform boundary) Shear Stress Sliding Past
What happens to rocks that are stressed? They can bend into folds They can break along faults
4 types of faults: 1) normal fault – caused by tension – hanging wall moves down
4 types of faults: 2) reverse fault – caused by compression – hanging wall moves up
4 types of faults: 3) thrust fault – caused by very strong compression – plane of the fault is not very steep
4 types of faults: 4) strike-slip fault – caused by shear stress
18 Strike Slip Fault layers of rock slide by each other
Which way did the fault seem to move? Fault 1Fault 2
Right Lateral vs Left Lateral Which way did the fault seem to move? Fault 1Fault 2
Right VS Left Lateral Left lateral faults have moved (offset) to the LEFT. Right lateral faults have moved (offset) to the RIGHT. Fault AFault B Which is left lateral? Right lateral?
22 Review: Identify Each type of fault Normal Reverse ThrustStrike-Slip
Folds in rock layers: anticline – top of a fold: looks like an “A”
Folds in rock layers: syncline – bottom of a fold: looks like it “sinks” Sideling Hill, MD
Folds in rock layers: limb – slope of a side of a mountain
syncline anticline Identify the 2 folds.
Local Geology Which province has the most folds?
Put it all together: On your own 29 Stress Description Fault Plate Boundary Arrows showing motion of plates 1. Reverse 2. Divergent Shear Thrust compression Push together convergent Pull apart tensionnormal Slide past horizontally Strike-slip transform