It has long been recognized that circular ruins in the Southwest differ
from rectangular ruins, not only in shape but also in structural
features, as relative position and character of kivas. The relation
of the ceremonial chambers to the houses, no less than the external
forms of the two, at first sight appear to separate them from the pure
type.[30] They are more numerous and probably more ancient, as their
relative abundance implies.
[30] It is premature to declare that the kivas in circular ruins do
not belong to the vaulted-roofed type simply from want of observation
to that effect. In Penasco Blanco and other ruins of the Chaco Canyon
group, as shown in ground plans, they appear to be embedded in secular
rooms. Additional studies of the architectural features of circular
pueblos are desirable.
These circular ruins, in which group is included certain modifications
where the curve of one side is replaced (generally on the south) by a
straight wall or chord, have several concentric walls; again, they take
the form of simple towers with one row of encircling compartments, or
they may have a double wall with inclosed compartments.
Many representations of semicircular ruins were found in the region
here considered, some of which are of considerable size. The simplest
form is well illustrated by the D-shaped building, Horseshoe House,
in Hackberry Canyon, a ruin which will be considered later in this
article. Other examples occur in the Yellow Jacket, and there
are several, as Butte Ruin, Emerson, and Escalante Ruins, in the
neighborhood of Dolores.
In contrast to the village type consisting of a number of pueblos
clustered together, but separated from each other, where the growth
takes place mainly through the union of components, the circular
ruin in enlarging its size apparently did so by the addition of new
compartments peripherally or like additional rings in exogenous trees.
Judging from their frequency, the center of distribution of the
circular type lies somewhere in the San Juan culture area. This type
does not occur in the Gila Valley or its tributaries, where we have an
architectural zone denoting that a people somewhat different in culture
from the Pueblos exists, but occurs throughout the “Central Zone,” so
called, extending across New Mexico from Colorado as far south as Zuñi.
Many additional observations remain to be made before we can adequately
define the group known as the circular type and the extent of the area
over which it is distributed.
The following examples of this type have been studied by the author: