The talus and landslides are composed primarily of the material from the
Tower and the Hulett sandstone.
Talus from the Tower forms a broad apron that completely surrounds the
Tower. The talus extends from high on the shoulders of the Tower down to
and across the sedimentary rock. Locally, landslides of this talus have
extended through valleys in the sedimentary rock down almost to the
level of the surrounding streams. The talus from the Tower is composed
of fragments of the columns that range from a few inches in diameter to
large sections of the columns as much as 8 feet in diameter and 25 feet
long.
The cliff of Hulett sandstone that surrounds the Tower breaks off into
rectangular blocks that form talus slopes at the base of the cliffs and
locally large landslides down the hill below the cliffs. These blocks of
Hulett sandstone range in size from a few inches to many feet in
diameter. The talus material from the Tower has at several places
overlapped the cliff of Hulett sandstone and become mixed with the
material from the cliff.
About 1,400 feet north of the Tower are two patches of what is believed
to be talus formed from sedimentary rocks that once surrounded the
Tower. The talus consists of fragments of medium-grained brownish-white
sandstone and, what is apparently, a highly silicified gray or white
fine-grained quartzite. The sandstone resembles that found in the Lakota
(Darton and O’Hara, 1907, p. 3) that lies about 200 feet
stratigraphically above the Redwater shale in the area west of the
Monument.
The sandstone and quartzite occur in angular blocks that range from less
than 1 inch to several feet in diameter. The spaces between the blocks
are filled with a yellowish or brownish-white sand.
The Lakota sandstone at one time surrounded the Tower and it is believed
that these blocks are residual blocks that have not been removed by
erosion.