Geological Time and Dating
This type of dating compares older and younger rock layers without giving a numeric age.
Relative Age Dating
Rocks formed from cooling magma are of this type.
igneous rocks
According to this law, a fault or intrusion must be younger than the rock it cuts through.
Law of Cross-Cutting Relationships
These waves refract or bend when they enter rock of a different density.
seismic waves
This EM wave has more energy than visible light and can cause sunburns.
Ultraviolet (UV)
Rock layers form over this time scale, ranging from millions to billions of years.
Geological Time Scale
At mid-ocean ridges, new crust forms because magma does this.
rises and cools
Intrusions, faults, and dikes found cutting across layers help scientists identify this.
relative age of geological features
When seismic waves lose energy as they pass through fractured rock, this process occurs.
dissipation
Dark surfaces heat faster because they do this with solar energy.
Absorb more energy
A layer dated to “270 to 530 million years old” is using this type of dating.
Absolute Age Dating
Heat and pressure create this category of rock.
metamorphic rocks
A surface showing missing time caused by erosion or uplift is called this.
unconformity
Compression and rarefaction describe the motion of this type of seismic wave.
P waves
The term for reflecting sunlight, often higher on bright surfaces like snow or sand.
Albedo
This principle states that in undisturbed layers, the oldest rocks are at the bottom.
Law of Superposition
This type of boundary creates mountains like the Rockies through compression.
convergent boundary
Even if rock layers are tilted or folded, this original order remains.
age order from oldest to youngest
Seismic waves travel faster through this type of rock: dense or less dense
dense rock
Longer wavelengths like infrared have this level of energy compared to shorter wavelengths.
lower energy
When an oceanic plate sinks beneath a continental plate, this process happens.
subduction
This rock group forms in layers from compacted sediments and includes many Grand Canyon formations.
sedimentary rocks
When rocks appear flipped upside down due to impact forces, like a meteor crater, this disturbance must have occurred.
overturning
A wave that slows and bends downward as it enters a deeper, denser layer is experiencing this interaction.
refraction
Scatter, absorb, and reflect are all interactions between sunlight and this layer of Earth.
the atmosphere