8. The boulders of mixed colors topping the pedestals of Zuñi
sandstone are the Basal Conglomerate of the Dakota formation. This
involved erosion and reworking of the old surface (Zuñi) plus the
deposition of new materials. Thus some of the light colored particles in
the Dakota are Zuñi sandstone.
The steps cut in the rock were constructed by the National Park Service.
They are not the work of prehistoric Indians.
9. The line, to the left of the post, extending through the rock on
both sides of the mesa, is one of the principal causes of the
development of the box canyon. After El Morro was buried by several
thousand feet of younger rocks, some 60 million years ago, it was
subjected to great pressures from the weight of the overlying rocks and
the movements which caused the Zuñi Mountains to project so far above
sea level. These pressures caused the sandstone to crack into the long
openings which we call joints. As running water and wind gradually
removed the overlying rocks, the waters were able to run down into the
joints and, alternately freezing and thawing, broke up the rock into
small fragments which could be washed away.
If you stand on this line and look down the box canyon to the west, you
can see that each steep canyon wall is simply one side of a joint, while
the material on the other side has been eroded away. If you look
eastward towards the headquarters area, along this joint line, you can
see how El Morro maintains its vertical walls by breaking into blocks
which fall away from the main mass of the sandstone and leave a vertical
joint face. This joint line is different from the others which you may
have noticed in climbing over the rock because it goes so far and cuts
through the rock so deeply.
10. The dark colored splotches are lichens. A lichen is composed of
two different organisms, an alga and a fungus, living together and
supporting each other. The fungus furnishes the moisture for the alga,
and the alga the food for the fungus. This coexistence is known as
symbiosis.
As you walk from No. 10 to 11, you will pass several potholes that
become pools of water after a rain. Some of these were artificially
enlarged by the Indians who lived on the mesa top, to serve as
supplementary sources of water.
11. The dark color here is caused by carbonized remains from the
plants which grew in the ancient swamps. Coal is formed in much the same
way, but there is too much inorganic material in this seam to produce
coal. This is the coal-like seam mentioned at No. 7. On the very top,
the dirt is from the Mancos formation of Cretaceous age, and is composed
of marine shales deposited in the ancient sea which covered the area. It
was originally much thicker, and is younger than any of the other rocks
exposed here.
Immediately ahead and extending to the right for nearly 300 feet is the
ruin called _Atsinna_, a Zuñi word referring to the “writing on rock.”
12. Atsinna, the larger of the two ruins, is approximately 200 by 300
feet, the size of some city blocks. Like the other village, parts of it
probably were three stories high, mainly along the north side. It was
terraced down toward the south, thus providing a southern exposure. You
are standing on the second floor level about ten feet above the original
ground level. The first floor was filled with debris from the collapse
of the upper stories.
The Indians obtained most of their water from the pool at the base of
the rock, as did the later Spanish and American travelers, but they also
caught as much water as they could on the mesa top.
13. This round room, is called a _kiva_. Kivas were built primarily
for religious ceremonial reasons, but had other purposes, just as the
large halls in cities today are used for exhibits, concerts, lectures,
and other activities. In addition to religion, these rooms were used for
workrooms, playrooms, general meeting places, fraternal society
meetings, etc.
[Illustration: _A portion of Atsinna. Part of the square kiva is
shown at lower left_]
Now contrast this round kiva with the square kiva across the trail
toward the northeast. Both kivas served the same functions, but they
represent two different architectural styles or traditions in use at
approximately the same time.
[Illustration: _The box canyon as seen from its eastern end looking
west_]
[Illustration: _Looking out over Inscription Rock from the south_]
Atsinna was occupied during the 13th and 14th centuries. The reason for
the abandonment of this site is not definitely known. Perhaps the
Indians found that the growing seasons were too short at this elevation
and they had too many crop failures. Apparently these people moved to
the west, where they founded the several Zuñi villages known in historic
times. There, around the present pueblo of Zuñi, the growing season is
slightly longer and irrigation can be practiced, and possibly the soil
is more fertile.
The prominent peak on the horizon to the south is called _Cerro Alto_,
which is Spanish for high mountain. This peak is a volcanic cinder cone.
14. The stones you see at this station were used for grinding corn
after it had been dried and stored. The corn was placed on the large
stone called _metate_ and ground with the smaller stone called _mano_.
15. The trail now descends from the mesa top back to the Monument
headquarters. We hope that you have enjoyed your trip over Inscription
Rock. Should you have any questions, the ranger on duty will be happy to
be of assistance.
PUBLISHED IN COOPERATION WITH THE NATIONAL PARK SERVICE BY
SOUTHWEST PARKS AND MONUMENTS ASSOCIATION
221 NORTH COURT
TUCSON, ARIZONA 85701
[Illustration: SOUTHWEST PARKS AND MONUMENTS ASSOCIATION • NATIONAL
PARK SERVICE]
Southwest Parks and Monuments association was founded in 1938 to aid and
promote the educational and scientific activities of the National Park
Service. As a nonprofit organization authorized by Congress, it makes
interpretive material available to park visitors by sale or free
distribution. All net proceeds support the interpretive and research
programs of the National Park Service.