Prof. Mohammad Gameil
Lab. 7
Stratigraphy and Lithologic Correlation
1.
a. Draw lines between the three stratigraphic sections below to
connect the geologic contacts between similar lithologies. (USE A
RULER!!.) Note that each vertical column is a stratigraphic section.
Each lithologic unit can be regarded as a bed.
b. How many beds can be correlated across all three sections?
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Prof. Mohammad Gameil
c. How thick is the thickest stratigraphic section (or column of rocks)?
d. A bed of coal is present in sections B and C. How deep would you have to drill in
section A (starting at the top of the section, up near the letter A) to reach the
buried coal seam?
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2.
a.
Draw lines to correlate the two sections below.
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Prof. Mohammad Gameil
b.
Which section (A or B) contains an unconformity?
c.
Which units are missing from that section because of the unconformity?
d.
Label the position of the unconformity with an arrow and the word
"unconformity".
e.
What type of unconformity is it?
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3.
a.
Draw correlation lines between the three sections below.
Note that the units vary in thickness in each section.
b.
What happens to the conglomerate in section C? Why is it not
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Prof. Mohammad Gameil
present in section A or B?
c.
Why does the thickness of the sandstone change from section A to
section B?
d.
In which direction (west or east?) was the land?
e.
In which direction (west or east?) was deeper water?
f.
Label the right side of section C with arrows to illustrate transgresion
(T) and regression (R).
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Prof. Mohammad Gameil
4.
a.
Correlate the three sections below. (Note that the limestone
unit is present only in sections A and B, and that it is much
thinner in section B. It has thinned to the point where it is
not present at all in section C.) This is called a pinchout.
b.
What type of sequence (transgressive? regressive? or
transgressive-regressive?) is represented here, as indicated by the
vertical sequence of facies?
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Prof. Mohammad Gameil
c.
Label the column on the left with up-pointing arrows to indicate
the part of the sequence which represents a transgression (T), and
the part which represents a regression (R). Label the arrows T or
R.
d.
These sediments were deposited in an ancient sea. Based on the
rock types, which facies (not section) was deposited nearest to the
mainland?
Sandstone i
s at the beginning of the transgression and the end of the
regression, so it is the facies deposited closest to shore.
e.
Which facies (not section) was deposited farthest from the land?
Limestone is found at the height of a transgression, so it is
deposited furthest from land.
f.
In which direction (west or east) was the land?
Deep-water limestone is not found in section C so that is the
direction closest to land.
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