Page 330 - Laboratory Manual in Physical Geology

1. What is the gradient of the ancient

upland surface in FIGURE 11.4 ?

Show your work.

2. What is the name of the modern stream drainage pattern from FIGURE 11.2 that is developed in the Lake Scott quadrangle

( FIGURE 11.4 ), and what does this drainage pattern suggest about the attitude of bedrock layers (the sediment layers

beneath the ancient upland surface) in this area?

3. Notice in FIGURE 11.4 that tiny tributaries merge to form larger streams. These larger streams become small rivers that

eventually merge to form the Mississippi River. Geoscientists and government agencies classify streams by their order
within this hierarchy of stream sizes from tributaries to rivers. According to this stream order classification , streams
with no tributaries are called first order streams. Second order streams start where two first order streams merge (and
may have additional first order streams as tributaries downstream). Third order streams start where two second order
streams merge (and may have additional first or second order tributaries downstream). Most geoscientists and government

agencies include intermittent streams (marked by the blue dot and dash pattern in FIGURE 11.4 ) as part of the stream order

classification. The intermittent stream in Garvin Canyon ( FIGURE 11.4 and below) has no tributaries so it is a first order

stream. Notice, on the map below, how the drainage basin ( FIGURE 11.1 ) of the stream in Battendorf Canyon is defined

by a red line. Draw a similar line, as exactly as youi can, to show the boundary of the Garvin Canyon drainage basin.
0.62
(
m
1 km (0.62 mi)mi)
1 1 km (0.62 mi)
k

(Courtesy of USGS)
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