Laboratory Manual for Introductory Geology 4e

FIGURE 6.6 Sediment sorting.
(a) Poorly sorted sediment.
(b) Moderately sorted sediment.
(c) Very well-sorted sediment.
Very poorly sorted Poorly sorted Moderately sorted Well sorted Very well sorted
(d) In a poorly sorted sediment, there is a great variety of different clast sizes, whereas in a well-sorted sediment, all the clasts
are the same size.
EXERCISE 6.4
What Could Move the Clasts?
Name:
Course:
Section:
Date:
Some agents of transport can move sediment that ranges widely in grain size. Match the letter of each transporting agent
from the left-hand column with the maximum grain size it can transport in the right-hand column.
(a) house-sized block
(b) boulder
(c) cobble
(d) sand
(e) silt
(f) mud
turbulent stream during a flood
very slow-moving stream
ocean waves or desert winds
glacial ice
quiet water
fast-moving stream
EXERCISE 6.5
Interpreting Sorting
Name:
Section:
Course:
Date:
Look at the three sets of clasts in Figure 6.6a–c. Suggest possible transporting agents that could be responsible for each.
(a) Poorly sorted:
(b) Moderately sorted:
(c) Very well sorted:
158 CHAPTER 6 USING SEDIMENTARY ROCKS TO INTERPRET EARTH HISTORY