National Monument: created by Presidential Decree (Antiquities Act of 1906)

National Park: established by an Act of Congress (Organic Act of 1916)

• To preserve natural areas for future generations

• To provide for enjoyment of natural areas by the public

• Original horizontality:once flat, then bent

• superposition: relative sequence if on bottom came first

• cross-cutting relationships: tears were once whole

• occurrence of inclusions: one rock included in another, whatever is included is older

• similarity of rock type
• similarity of rock sequence
• use of fossil, mineral, or chemical evidence

• Eon
• Era
• Period
• Epoch

• year= annum (a)

• thousands= Ka

• millions of years = Ma

• billions of years= Ga

• Phanerozioc (542 Ma-present) visible life
• Proterozoic (2500-542 Ma) primitive life
• Archaean (2500-3850 Ma) hidden life
• Hadean (~4550-3850 Ma) hellish conditions

• Precambrian (4550-542 Ma) no macroscopic life forms
• Paleozoic (542-245 Ma) Age of Amphibians
• Mesozoic (245-66 Ma) Age of dinosaurs
• Cenozoic (66 Ma- present) Age of Mammals

• gaps in the rock record
• a long period of time during which deposition ceased, ersosion removed previously formed rocks, and then deposition resumed

1. Disconformity:
2. Angular Unconformity
3. Nonconformity

• sedimentary rock overlying sedimentary rock
• period of non-deposition and/ or erosion
• more common but far less conspicuous

• sedimentary rock overlying sedimentary rock having a different orientation
• period of "mountain- building"/ uplift and erosion
• consists of tilted or folded sedimentary rocks that are overlain by younger, more flat-lying strata
• indicates that during pause in deposition, a period of deformation (tilting or folding) and erosion occured

• sedimentary rock overlying metamorphic or igneous rock
• period of extensive erosion followed by subsidence and deposition
• there must have been period of uplift and the erosion of overlying rocks

• equal the force per unit area (pressure) exerted against an object
• ex. two hands pushing against one another

• stress in all directions
• ex. when under water, water pressure from all sides

• stress in one direction
• ex. one hand forcing the other in one direction
• directed stress can result in compression, extension, or shear

• the deformation (permanent or temporary) produced in any material as a result of applied stress
• stress produces strain

• equal from all sides
• reduces volume

• all changes in the original shape and / or size of a rock body
• rock deformation controlled by material properties, time, temperature, and pressure

material rebounds to original form when stress is removed (however there is a limit)

Ex. bendable wood

results when the elastic limit is exceeded- permanent failure

ex. snapping wood in two

material remains deformed when stress is removed

ex. sqeezing clay

• result of extension
• hanging wall (down)
• foot wall (up)
• dip (inclination) generally from 45- 90 degree

• result of compressions
• hanging wall (up)
• foot wall (down)
• dip greater than 45 degrees

• result of compression
• thrust faults can place older rocks over younger rocks and can have displacements measured in many tens of km
• thrust faults provided the key to understanding the geology of Glacier NP and the Great smoky Mtns. NP
• shorten things by stacking things up

• result of shear
• dominant displacement is horizontal and parallel to the trend, or strike, of the fault surface 
• typically steep or near vertical

• Limb: area of least curvature
• Hinge: area of maximum curvature
• Hinge Line: (fold axis)
• Hinge plane (axial plane)

• Anticline (antiform) - closes upwards
• Syncline (synform)- closes downwards

• Normal or symmetric- limbs have same inclination on both sides
• Asymmetric
• Overturned
• Plunging: v shaped outcrop pattern- arrowhead

• Anticline: oldest rocks in core of fold- layers pushed up then eroded
• Syncline: youngest rocks in core of fold

• the vibration of eath produced by the rapid release of energy- caused by slippage along a fault in the earth's crust
• energy released radiates in all directrions from source, focus in the form of waves

movement (displacement) along a fault zone...

• releases seismic energy
• transmitted through Earth and along the surface
• manifested as an earthquake

earth's crust is under stress, stress builds to the point that the earth breaks, EARTHQUAKE

• body wave
• primary
• compressional
• particle motion parallel to direction of propagation
• same direction energy is moving
• alternately expand and contract
• body waves go through earth
• travel the fastest
• transmitted by both solids and fluids because the resist a change in volume when compressed and will elastically spring back once the force is removed
• push pull waves- they push (compress) and pull (expand)

• body wave
• secondary
• shear
• particle motion is perpendicular to direction of propagation
• particle motion is perpendicular to seismic energy
• energy goes left to righ, motion goes up and down
• transmitted only by solids
• tells us part of earth's core must be fluid at some point b/c it doesn't transmit s waves
• temporarilu change the SHAPE of the material so fluids don't respond

Seismic Surface Waves

• energy dissipates with depth
• maximum intensity at surface
• love waves: back and forth motion
• Rayleigh Waves: retrograde rolling motion

• crust (silicate)

• mantle (silicate)

• core (ni-Fe  metal)

• Earth's outer core is fluid, responsible for magnetic flied and, in part, drives mantle convection