Chapter 21 Flashcards
1
Q
eon
A
longest time unit
2
Q
era
A
2nd longest time unit
3
Q
periods
A
defined by life forms
4
Q
epochs
A
small divisions of time-millions of years
5
Q
uniformitarianism
A
the processes occurring today have been happening for the earths entire life
6
Q
original horizonality
A
sedimentary rocks are deposited in horizontal layers
7
Q
superposition
A
in undisturbed rock sequence, the oldest rocks are on the bottom
8
Q
cross cutting relationships
A
the intrusion or fault is younger than what it curs across
9
Q
unconformity
A
gap in the rock record
10
Q
correlation
A
the matching of outcrops in different geologic locations
11
Q
dendrochronology
A
tree ring dating
12
Q
varves
A
alternating light and dark coloured sediments
13
Q
key bed
A
time markers
