Title: Stratigraphy
1Stratigraphy
- The study of the origin, relationship and extent
of rock layers (Strata).
2LithostratigraphyEach layer is a different rock
type.
ChronostratigraphyEach layer is a different age.
BiostratigraphyEach layer contains a different
fossil assemblage.
3Lithostratigraphic Units
Supergroup Group A Formation A Member A
Supergroup Group A Formation A Member B
Supergroup Group A Formation A Member C
Supergroup Group A Formation B Member D
Supergroup Group A Formation B Member E
Supergroup Group A Formation B Member F
Supergroup Group A Formation C Member G
Supergroup Group A Formation C Member H
Supergroup Group B Formation D Member I
Supergroup Group B Formation D Member J
Supergroup Group B Formation D Member K
Supergroup Group B Formation D Member L
Supergroup Group B Formation D Member M
Supergroup Group B Formation E Member N
Supergroup Group B Formation E Member O
Supergroup Group B Formation E Member P
Supergroup Group B Formation E Member Q
Supergroup Group B Formation F Member R
Supergroup Group B Formation F Member S
Supergroup Group B Formation F Member T
Supergroup Group Formation Member Bed
4Lithostratigraphic ExampleGrand Canyon
5How do we Illustrate Stratigraphy?
- Stratigraphic Columns
- Cross Sections
- Geologic Maps
6Stratigraphic ColumnJohn Day Fossil Beds NM
7Geologic MapsSnoqualmie Pass
8Chronostratigraphic Map of Washington
9Cross Sections
10Principles (Laws) of Stratigraphy
- Principle of
- Original Horizontality
- Superposition
- Lateral Continuity
- Cross Cutting Relationships
- Inclusions
- Faunal Succession
- Walthers Law
11Nicholas Steno
121. Principle of Original Horizontality
132. Principle of Superposition
143. Principle of Lateral Continuity
15Lateral Continuity
16Charles Lyell
174. Principle of Cross Cutting Relationships
185. Principle of Inclusions
196. Principle of Faunal Succession
Sketch by Baron Cuvier (1769-1832)
20William Strata Smith
216. Principle of Faunal Succession
" . . . each stratum contained organized fossils
peculiar to itself, and might, in cases otherwise
doubtful, be recognized and discriminated from
others like it, but in a different part of the
series, by examination of them."
22Biostratigraphy
Superzone - Biozones - Subzones
Defined by first and last appearance of index
fossils and/or fossil assemblages
23Diatoms
24BoundariesConformable Bed Contacts
Gradational
Sharp
25BoundariesUnconformitiesGaps in Rock Gaps in
Time
26Types of Unconformities Nonconformity
27Nonconformity - Grand Canyon
28Using Inclusions to Recognize a Nonconformity
29Types of Unconformities Angular Unconformity
30Formation of an Angular Unconformity
31Angular Unconformity in the Grand Canyon
32The Angular Unconformity at Siccar Point,
Scotland
Source Edward A. Hay, De Anza College,
Cupertino, CA
33Types of Unconformities Disconformity
34Formation of a Disconformity
35Walthers Law
Johannes Walther(1860-1937)
36Concept ofSedimentary Facies
Depositional Environments
Facies
Sedimentary Facies refers to all of the
characteristics of a particular rock unit. The
characteristics of the rock unit come from the
depositional environment.
37Facies Example
Facies Change
A Sandstone facies (beach environment) B
Shale facies (offshore marine environment) C
Limestone facies (far from sources of terrigenous
input)
38Marine Transgression Sea Level RiseMarine
Regression Sea Level Fall
39Walthers Law
Sedimentary environments that started out
side-by-side will end up overlapping one another
over time due to transgressions and regressions.
Facies
Limestone
Shale
Siltstone
Sandstone
Lagoon
Beach
Reef
Near Shore
Environment
40Marine Trangression
Walthers Law
41Marine Regression
42The sea goes in, the sea goes out.
43Blue No deposition
44Vail Curve of Sea Level History
Transgression Regression
45Correlation
46A
B
C
47Example of Correlation
48Colorado Plateau Correlation
49Colorado Plateau Correlation
50Chronostratigraphic Units
- Chronostratigraphic (Time-Rock) Unit
- Eonothem
- Erathem
- System
- Series
- Stage
51Chronostratigraphy and the Development of the
Geologic Time Scale
52Chronostratigraphic Time Units
- Time Unit
- Eon
- Era
- Period
- Epoch
- Age
- Time-Rock Unit
- Eonothem
- Erathem
- System
- Series
- Stage
53GeologicTimeScale
54(No Transcript)
55Relative Dating of Rocks Using Stratigraphic
Principles
56Example 2 of Relative Time