University of Virginia Library

Description and Technique

The refuse heap of Mound 50 measured on the present surface
roughly sixty by one hundred feet (Fig. 7); but its original extent
was probably somewhat larger, for the edges were lost under the
blanket of drift deposited since prehistoric times. The mound was
marked off into six foot squares, designated from north to south as
Trenches and from east to west as Sections. Excavation began on the
north end, Section I, in nine trenches, each square being worked by two
students at a time. The students supervised the excavation in six inch
absolute levels, designated by numbers running from the bottom upward
and measured by transit from a base line laid at the bottom of
the northern edge of Section I, where a preliminary trench was cut.
The actual digging was done mostly by Navajo laborers, but the students
removed the shards from the soil as it was shoveled up or as they
slowly shoveled it up themselves. Screens were not used because it was
thought that in the large amount of soil to be removed from each square
the small number of shards probably missed by the quicker technique
of picking over the material would not be significant. It was found to
be more difficult to teach the students to be practical than to be careful;
they were inclined to section the dump, inch by inch, with trowels!

The shards collected were sacked and the sacks marked with the
Section, Trench, Level, date and initials of the worker. Most levels
required several shifts of work, morning and afternoon, and more than
one bag for the shards. The shards were brought to the laboratory tent
at the end of each shift, and there they were washed and classified by
the laboratory classes.

After the shards had been classified, the classification checked, and
percentages computed, these percentages were entered on large charts
marked into Sections, Trenches, and Levels, representing the dump, as
well as on individual blanks mimeographed for the purpose. The study
of associations of types of pottery by Section and Level indicated that
the complexes for each period were consistent except for the overlapping
of some types from period to period, as might be expected in
any continuously occupied site. In the Chetro Ketl dump, holding over
of types was marked; there was never a strict demarkation of period by
presence or absence of certain types but only by preponderance of certain
types. Types first made in small percentages in one period grew
to be the most popular and characteristic types of the next period and

Figure 7
Graphs of Refuse Mound

fell to small percentages again as they died out in the succeeding
period. Hence, periods and their strata can not be identified by one
pottery type any more than a skeleton may be classified racially on
one characteristic; a study of the predominating characteristics, however,
will mark off strata by period, and the lines of these strata were
drawn onto the charts for each section. Comparison of the outlines
of the topography of the strata for each period through all the sections
provided an outline of the shape and slopes of the refuse mounds of
the three period represented, as far as they were uncovered. No indication
of division of the dump by strata was apparent in the trench
profiles.