Midterm 2 Flashcards
Lecture 1
Slides 1-78
Deep time
the immense span of geological time +38-39
Human history in relation to deep geological time
Minuscule period
C
Some rocks may be involved with relative age dating in the numerical time
What is unconformity in relative/numerical time tell us?
missing rock in layer due to erosion or nondeposition resulting in a time gap
Physical principles:
Uniformitarianism Superposition Horizontality Lateral Continuity Cross-cutting relations
Principle of uniformitarianism states:
that the processes observed today were the same in the past
The Law of Superposition states:
that younger strata lie on top of older strata
The principle of horizontality states:
that all rock layers were originally horizontal
The Principle of Cross-Cutting Relationships states:
that intrusions and faults that cut across rock are necessarily younger than that rock
The principle of lateral continuity states:
that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. As a result, rocks that are otherwise similar, but are now separated by a valley or other erosional feature, can be assumed to be originally continuous.
Types of unconformities:
- Angular unconformity
- Nonconformity
- Disconformity
James Hutton
The first to recognize significance of angular unconformities, which he observed in Siccar Point, Scotland where the vertical ordovician sandstone is overlain by devonian redbeds that are gently dipping, a resulting missing time of 50 million years.
Angular unconformity
Slide 16
A time gap in the rock record is called? A. Nondeposition B. Nonconformity C. Nonconformity D. Uniformitarianism
Nonconformity
Nonconformity
18
Disconformity
19
Stratigraphic corelation
20,21
Geological column
22
Geolog time scale
23
Geological time in relation to life
Life’s evolution is positioned against the geologic column
Numerical age
- Radioactive decay
- Magnetostratigraphy
- Fission track dating
What does the radioactive decay and the chart of nuclides look like?
Half a rainbow
Antoine-Henri Becquerel
27
27
Antoine-Henri Becquerel
The first to recognize significance of angular unconformities, which he observed in Siccar Point, Scotland where the vertical ordovician sandstone is overlain by devonian redbeds that are gently dipping, a resulting missing time of 50 million years.
James Hutton
Lord Ernest Rutherford
Conducted experiments between 1898 and 1907 at McGill, which determined half-life and age, winning him the 1908 Nobel Prize.
Conducted experiments between 1898 and 1907 at McGill, which determined half-life and age, winning him the 1908 Nobel Prize.
Lord Ernest Rutherford
Which of the following methods is NOT used to determine the numerical age of rocks? A. Radioactive isotopes B. Fossil record C. Magnetostratigraphy D. Fission track dating
Fossil record
Radioactive dating determines the age of a mineral by
Measuring the ratio of parent-to-daughter isotopes, using parent half-life
Table: Isotopes Used in the Isotopic Dating of Rocks
?
Magnetostratigraphy
33
Fission track dating
34
Dating the geologic column
35
The age of the earth
36-37
The principles of fossil succession
13–14
Relative age determination
10-12
The hadean eon
41-43
Biography of earth timeline:
- Hadean eon
- Archean eon
- Proterozoic eon
- Phanerozoic eon
The archean eon
44-46
The Proterozoic eon
47-53
Shield terrain
48
Cratonic case
49
The great oxidation event
50
Edicacaran life
51
Pannotia
52
Snowball eart
53
The phanerozoic eon
54
Phaneros=
54
Zoic=
54
The Cambrian Explosion
57
Cambrian and ordovician life
56-58
Periods during cenozoic era
55
Periods during mesozoic era
55
Periods during paleozoic era
55
Timeline of eras
55
