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Test Number Two
Geology 364
Stratigraphy and Basin Analysis
Sequence Theory
The test is a mixture of scantron, computer graded questions, and interpreting and completing drawings. Answer True/False and Multiple Choice question on the scantron card. Answer other questions on the attached pages. Be sure to put your social security number on the scantron card.
RANDOM SAMPLING OF BASIC CONCEPTS:
TRUE/FALSE QUESTIONS; 2 points each, 30 points total:
- T/F Using the hummocky sequence to interpret rocks on the outcrop is a top-down process.
- T/F Drawing a 3rd^ and 4th^ order relative sea level curve for Briary Gap is a bottom-up process.
- T/F Color interpretation on the outcrop is a bottom-up process.
- T/F Tectonic interpretations are always top-down.
- T/F A representative autogenic processes would be eustasy.
- T/F Delta lobe switching is an autogenic process.
- T/F Individual storms are autogenic but climate is allogenic.
- T/F A TST is the result of an autogenic process.
- T/F A condensed section produced by a maximum flooding surface and one produced by a parasequence flooding surface are never the same thing.
- T/F Backstepping is the same as a transgression.
- T/F Retrogradation is the same as backstepping.
- T/F A composite sequence is one composed of parasequences.
- T/F Onlap and transgression are just two terms for the same thing.
- T/F Progradation cannot take place during a TST.
- T/F A ravinement surface is a type of sequence boundary.
The Effects of Sediment Influx and Subsidence on Accommodation TRUE/FALSE QUESTIONS; 2 points each, 14 points total: At the back are drawings labeled Subsidence and Sediment Influx. These questions are for those drawings.
- T/F Situation D will likely never fill the accommodation available.
- T/F Situation E does not result in permanent sediment accumulation.
- T/F Situation F is most likely to produce terrestrial environments.
- T/F Situations A and E are likely to produce the same outcome.
- T/F Situations C and F are likely to produce the same outcome.
- T/F The TST in G is more likely to happen with E than with D.
- T/F The TST in G is more likely to happen with A than with B.
High Stand
Low Stand
ALLUVIAL VALLEY
DELTA PLAIN
CONTINENTAL SHELF
CONTINENTAL SLOPE
SUBMARINE FAN High Sea Level R i s in (^) g Sea Lev el
Low Sea Level
Fa lling
Sea
L^ ev
el
High Sea Level
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Sequences and Depositional Systems: RIGHTS MINUS WRONGS MULTIPLE CHOICE QUESTIONS: 3 points each, 24 points total. The table below shows a series of environments across a shelf/slope/basin system plotted against an eustatic curve. Below that is a table showing processes or environments that might be present in each stage. For each selection below chose any and all choices that apply.
LOCATION A. Choose any and all environments/processes that apply to this location in the table.
- A=1A B=1B C=1C D=1D E=1E
- A= 2A B=2B C=2C D=2D E=2E
- A=3A B=3B C=3C
LOCATION C. Choose any and all environments/processes that apply to this location in the table.
- A=1A B=1B C=1C D=1D E=1E
- A= 2A B=2B C=2C D=2D E=2E
- A=3A B=3B C=3C
SELECT FROM THESE
1A Aggradation of entrenched channels 1B Along shore delta switching 1C Backswamp accumulation 1D Braided channels 1E Channel switching
2A Condensed section 2B Major shelf instability 2C Meandering channels 2D Mud accumulation on shelf 2E Rapid accumulation on slope
3A Rapid delta progradation 3B Rapid entrenchment 3C Sediment bypassing
RIGHTS MINUS WRONGS - MULTIPLE CHOICE; 3 points each, 60 points total: Gamma Log Interpretation drawings at the back of the test. Identify all examples which clearly exhibit complete records that show the features below.
Aggradation. Identify all examples which clearly exhibit this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Retrogradation. Identify all examples which clearly exhibit this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Progradation. Identify all examples which clearly exhibit this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Irregular. Identify all examples which clearly exhibit this feature across at least 2 parasequences.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Tidal type parasequences. Identify all records that posses this type sequence.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Shoreface type parasequences. Identify all records that posses this type sequence.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Typical TST record. Identify all examples which clearly exhibit this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Typical HST record. Identify all examples which clearly exhibit this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
Interpreting A Relative Sea Level Curve RIGHTS MINUS WRONGS - MULTIPLE CHOICE; 8 points each, 24 points total: At the back is a page with 5 strip logs at the top and a relative sea level curve at the bottom. The questions below concern identifying the correct strip log with the correct location on the curve.
T i m e ( 1 0 5 y e a r s )
M e t e r s A b o v e a n d B e l o w R e f e r e n c e P o s i t i o n a t T i m e Z e r o 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
(^0) - -40-
_- -100-
-160-_
2040
60 80100
120140
160180
200 220240
260280
300 320340
360380
400420
440 460480
500 520540
_- -40-
-100-
-160-_
2040
60 80100
120140
160180
200 220240
260280
300 320340
360380
400420
440 460480
500 520540
0
LOCATION 1. Choose the strip log most likely to match this location.
- A B C D E
LOCATION 3. Choose the strip log most likely to match this location.
- A B C D E
LOCATION 4. Choose the strip log most likely to match this location.
- A B C D E
Subsidence and Relative Sea Level Curves TRUE/FALSE QUESTIONS; 2 points each, 16 points total: These questions examine the relationship between rates of tectonic subsidence, accommodation, and systems tract preservation.
- T/F Low Stand Deposits become less significant as basin subsidence rates increase.
- T/F Subsidence exaggerates onlap.
- T/F With increasing subsidence rates the relative amount of time the HST has to be deposited increases.
- T/F Incisement is likely to occur with
subsidence rates of 0 m/10^5 years?
- T/F When rates of subsidence exceed rates of eustatic fall accommodation increases.
- T/F Cratons are likely to have well
developed High Stand Tracts.
- T/F Rift systems will not likely to posses well developed sequence deposits with all the systems tracts well represented.
- T/F Parasequences will be better developed in low subsidence rates rather than high ones.
LOW STAND UNCONFORMITIES. Identify by the letters of lithofacies both directly above and below all examples of this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
- A=K B=L C=M D=N E=O
- A=P B=Q C=R D=S E=T
- A=U B=V C=W D=X E=Y
- A=Z B=AA C=BB D=CC E=DD
RAVINEMENT SURFACES. Identify by letters all lithofacies representing this feature.
- A=A B=B C=C D=D E=E
- A=F B=G C=H D=I E=J
- A=K B=L C=M D=N E=O
- A=P B=Q C=R D=S E=T
- A=U B=V C=W D=X E=Y
- A=Z B=AA C=BB D=CC E=DD
- The Parasequences in lithofacies C are: A = Prograding B = Retrograding C = Aggrading
- The Parasequences in lithofacies M are: A = Prograding B = Retrograding C = Aggrading
Locating the Stratigraphic Section
- Graphic Construction: 10 points. At the back is a “Geologic Cross Section of an Idealized Seismic Stratigraphic Section.” Draw a vertical line on this cross section showing the most likely location of the strip log.
Drawing a Relative Sea Level Curve
- Graphic Construction: 30 points. At the back is the Stratigraphic Strip Log you used for the last set of questions on Stratigraphic Section Interpretation. Only now, draw a Relative Sea Level Curve in the column provided.
Wheeler (Chronostratigraphic) Diagrams
- Graphic Construction: 30 points. At the back is a “Geologic Cross Section of an Idealized Seismic Stratigraphic Section.” Draw a Wheeler time/space diagram for the cross section in the table below the cross section. NOTE you do not have to color code the Seismic Stratigraphic Section, but DO color code the wheeler diagram.
