Final Test with
complete
verified
solutions
relative dating
any method of determining whether an event or object is older or
younger than other events or objects
absolute dating
any method of measuring the age of an event or object in years
original horizontality
Principle stating that sedimentary rocks are deposited in horizontal
or nearly horizontal layers.
Superposition
a principle that states that younger rocks lie above older rocks if
the layers have not been disturbed
lateral continuity
Principle that states that an original sedimentary layer extends
laterally until it tapers or thins at its edges.
Law of inclusion
, a rock fragment included in a bed has to come from an older feature
than that bed
law of cross-cutting relationships
Principle stating that a fault or intrusion is younger than the rock it
cuts across.
conformable sedimentary contact
layers of rock that have been deposited essentially without
interruption. shows a full record of that time interval
unconformable sedimentary contact
represents a hiatus in deposition, and results in a loss of time in the
geologic record
angular unconformity
an unconformity in which younger sediment or sedimentary rocks
rest on the eroded surface of tilted or folded older rocks
Disconformity
a type of unconformity in which the sedimentary layers above and
below the unconformity are parallel
Nonconformity
An unconformity in which older metamorphic or intrusive igneous
rocks are overlain by younger sedimentary strata.
intrusive igneous contact
younger than the bed it intrudes, can be a dike (vertical), sill
(horizontal), or pluton depending on size and orientation
extrusive igneous contact
lava or pyroclastic flows deposit similar to sedimentary beds, which
causes minor contact metamorphism to rocks below the flow
fault contact
the surface between two rocks that slid or are sliding past one
another
Geologic timescale