University of Virginia Library

I. Part I

Section A

CULTURE COMPLEXES AND SUCCESSION
IN THE REFUSE MOUND

By Florence Hawley

Technique.—In 1936, the refuse mound between Bc 50 and 51
was surveyed and divided into 6′ squares, designated as trenches from
north to south and as sections from east to west. Removal of the
material from all the trenches within a section exposed a new face
just 6′ south of the preceding face. The debris was removed by 6″
arbitrary levels measured from a base line located at the bottom of
a trench cut across the north end of the dump. During the 1936
season, Sections 1, 2, 3, and 4 (in part) were excavated, and a report

on the results of the pottery type succession and period complexes was
published.[1]

As the work of 1936 had given a thorough study of the east to west
distribution of culture strata in the northern area of the dump, it
was decided to push work faster from north to south in 1937. Before
excavation of the mound was continued, the 6′ trenches and sections
were divided into 3′ areas, and the trench numbers used the year

before were changed to conform to those of the new smaller trenches.
(See Fig. 1.) For this season, certain evenly distributed trenches
(3, 7, 11, and 15, in sections 5, 6, and 7) were chosen for excavation
and the material was removed in 6″ arbitrary levels, measured above
the base line used the preceding season. At the end of the field
session, trench 15 had not been completed in section 7, but the material
from the others had been sifted from the soil, washed and classified.
The north, south, east, and west faces of each trench in each section
were drawn in profiles so that the changes in deposits could be compared
with the pottery type changes in complexes and in actual percentages
per type.

Figure 2—Sectional Profiles of Refuse Mound

On a series of cross section drawings, representing the 7 sections
excavated in 1936 and 1937, the sherd percentages were listed in each
of the rectangles representing the arbitrary levels of excavation.
The merging of one period into another was clearly shown by the rise
and fall of percentages of the various types from the bottom to the
top of the dump, the cultural divisions being indicated by complexes,
based on predominance or rank order of associated types rather than
by simple presence or absence of individual types.

Lines were drawn to mark the approximate limits of each pottery
complex in the trenches excavated and were continued as dotted lines
across the unexcavated portions to meet the lines indicating the same
complexes in the other excavated trenches. Upon these drawings of
pottery successions, the drawings of deposition variations within the
faces were superposed for comparison. (See Fig. 2.) In some cases the
pottery complexes appeared to coincide with distinguishable strata;
in some cases they did not. The south face of section 6 (see Fig. 1)
was depicted in a chart (see Fig. 3) indicating the relation of the

various deposition profiles between Bc 50 and 51 and will be discussed
in detail in Part I, B.

Pottery Complexes.—At least in a site such as this, pottery
complexes must be taken as defined by characteristic proportions of
various types rather than (with possible rare exceptions) by the
presence or absence of particular diagnostic types. The individual
types making up each complex often occur in more than one culture
period. In the absence of multitudinous tree ring dates and unequivocal
associations between building dates and sherds or vessels found,
it is impossible to set exact beginnings and ends to the occurrence of
any one complex or to the occurrence of any one type. Known facts
from the historical pueblos, documenting the rise and fall of popularity
of individual types, strongly suggest that, as a general thing, it
would be unreasonable to postulate an abrupt and complete cessation
of the manufacture of any given pottery type. That there is, nevertheless,
a strong trend toward uniformity of association of certain

types in roughly similar proportions at various stratigraphic levels
will emerge from the data to be presented.

In addition to the natural holdover of obsolescent types and the
comparatively few sherds (or vessels) resulting from initial experiments
with new types, the mixing of material by rain and other
natural forces, human intrusions for burying or other purposes, and
disturbance by rodents explain the lack of a completely neat correspondence
between superimposed strata and individual pottery types.
If, however, there is some approach to constancy (over and above
what could be anticipated from mere random sampling) between
succession of stratigraphic levels and pottery complexes (as defined
by relative proportions of different types), it then seems proper to
interpret these data as valid signposts of cultural history. The
predominant complexes of relatively undisturbed strata, however,
should be expected to run fairly consistently with small amounts of a
given type (or types) toward the bottom, increased percentages as that
type (or those types) rises to prominence, and decreasing percentages
as another or others come into fashion. In a refuse mound situated
on a slope samples taken from the various levels of sections at the
upper end may be expected to have been less disturbed by sheet wash
than the lower sections farther to the north.

At the bottom of trenches 7 and 15 in section 6 (see Table 1) we
find 100% Lino Gray.[2] In the lowest levels of the excavated trenches
of sections 4 and 5 Lino Gray is accompanied by small percentages of
other types:

             

	Sect. 4	Sect. 5
Lino Gray	82	72
Kana-a Gray		17
La Plata B on W	9	6
Reserve Brown[3]		6
Deadman's B on R (intrusive?)	9
	(17 sherds)	(11 sherds)

Unfortunately (and probably significantly), all of these samples
from the lowest levels are very small. But while Lino Gray is actually
the most numerous single type in all complexes, it is distinctly more
predominant in these lower levels. The pottery complex characterized
by a dominance of Lino Gray and with La Plata Black on White as an
associated type will be called the Lino Gray Pottery Complex.

This complex did not appear in section 7. The lower levels of
all excavated trenches of section 7 are distinguished by the prominence
of Red Mesa Black on White and the complex of which these
levels are representative is hence called the Red Mesa Pottery Complex:

                 

Lino Gray	43.0
Red Mesa B on W[4]	35.9
Exuberant Cor.	10.2
Escavada B on W	5.3
Deadman's B on R	2.8
Gallup B on W	1.2 (probably intrusive?)
Kana-a Gray	0.8
La Plata B on W	0.8
	(110 sherds)

Trade material associated with this pottery complex in other sections
included: Reserve Brown, Lino Black on Gray, Kana-a Black on White,
Abajo Red on Orange, a Black on Red identified by Brew[5] and Morris
as indigenous to the Four Corners country, and a Gray with Black
Smudged Interior from southwestern Colorado.[6]

Taking as a whole all the excavated trenches of section 7, the
levels above those represented of the Red Mesa pottery complex show
a different persistent association of types:

                       

Lino Gray	31.6
Exuberant Cor.	19.3
Escavada B on W	17.8
Red Mesa B on W	13.5
Chaco Cor.	7.7
Gallup B on W	6.3
Kana-a Gray	2.0
Wingate B on R	1.3
Deadman's B on R	.3
Chaco B on W	.1
Sunset Red	.1
	(2831 sherds)

Since perhaps the most distinguishing feature of this complex is
the greater prominence of Escavada Black on White it will be convenient
to call it the Escavada Pottery Complex.[7]

Cross finds in this complex are Winona Corrugated, Deadman's
Black on Red, Citadel Polychrome, Rio de Flag Brown, Rio de Flag

Smudged, Elden Corrugated, and Sunset Red from the Flagstaff
district; Tusayan Black on Red, Medicine Black on Red, Buff Black on
Red from the Kayenta district; Wingate Black on Red and Forestdale
Smudged from the Little Colorado; and something resembling but not
identical with Mogollon Red on Brown from the Mogollon district of
southwestern New Mexico.

The persistence of Lino Gray as the commonest single type
(although in decreasing percentages) in all three complexes would
seem to indicate one of three things: that Lino Gray continued for
a quite considerable period as a culinary ware or that enough mixing
of sherds was done by rain or by other forces to raise a great deal of
Lino Gray from the bottom of the dump to the top, or that what
appears to be Lino Gray are actually sherds from the bodies of various
other pottery types. Let us examine these three possibilities in
reverse order.

First, of the other types recognized to have bases indistinguishable
from those of Lino Gray, all but Kana-a Gray and Medicine Gray
show tooled or punched necks. If types with plain bases and tooled
or punched necks were used by the inhabitants of Bc 50 and 51 we
should find in the dump some of the neck sherds as well as some of
the base sherds. No such neck sherds have been recovered; hence it
seems very improbable that those types were used here. Medicine
Gray[8] has a base indistinguishable from that of Lino Gray or of
Kana-a Gray, but the neck is corrugated. Kana-a Gray has a base
like Lino Gray but neck bands form the upper part. Sherds from the
neck showing the wide flat bands and from the shoulder, showing the
junction between the plain base and the neck bands, are not uncommon
here. But although corrugated sherds which might be from the necks
of Medicine Gray rather than from fully corrugated vessels are
found, no neck sherd showing conjunction between plain base and
corrugated neck has yet been found in this dump. Therefore, we
conclude that the sherds classified as Lino Gray may have come from
Lino Gray vessels or may have come from the bases of Kana-a Gray
vessels in strata where neck-banded sherds are found, or that they
may possibly, but not very probably, have included some sherds of
Medicine Gray.

Second, some mixing undoubtedly did take place, but that this
alone could account for the predominance of Lino Gray in all three
complexes seems improbable.

We know that in the modern Pueblos, as probably in those
of the prehistoric Southwest, the culinary wares were much less
likely to change than the decorated wares. It is thus conceivable that
in some districts Lino Gray lasted for a very considerable period.
At present it would be hazardous to state that Lino Gray certainly

was as common or more common than Kana-a Gray in the period represented
by Escavada complex but the sherd evidence strongly suggests it.

Summary.—Three pottery complexes are distinguishable and may
be traced in superimposed mounds of varied shapes and depths.

Lino Gray Complex.—On approaching from the north face of the
dump, the Lino Gray Complex showed up first in a small mound at the
eastern edge of section 3 where it runs from trench 14 through 18 and
on into the unexcavated area. Its base lay 8′ below the surface. At
its peak it was 2′ thick but it dwindled to nothing at its western edge
in trench 15. This early mound of refuse was found to extend 6′
farther into the dump to section 4, where it was deeper beneath the
surface, its peak here being 12′ below the bottom deposition of
section 3 and its depth going down for 2′ farther. This puts
the base of the Lino Gray Complex in trench 15, section 4, at 6′ below
the surface. No trenches east of 15 were excavated, so the eastern
periphery of this debris was not located in this section. On the west
the peak dipped precipitously and disappeared in trench 14.

No similar deposit was found in section 5, but in section 6, a
6″ lense of this material was found at the bottom of trench 15. No
excavation extended as far east as trench 15 in section 7.

In the western side of the dump, the Lino Gray Complex did not
appear until section 4, where a deposit 2′ deep was found at the bottom
of trench 2. Three feet farther south in trench 3, section 5, a Lino
Gray Complex lense 6″ thick was found with its base 6″ below the base
in section 4. This lense did not extend into section 5, but another lense
6″ thick was encountered in trench 7 of section 6. Section 7 shows no
Lino Gray Complex.

Red Mesa Pottery Complex.—This extended from the top of
trench 8, section 1 down 4′ to the undisturbed soil. Sloping downward
to the west, it disappeared in trench 8. In section 2, it made up almost
the entire lower layer of the excavated area, from trenches 2 to 18,
dipping at the base in trenches 7 and 8 and again in trenches 15 and 16.
The peak, in trench 9, was closer to Bc 50 than Bc 51, but in section 3
this debris shows two distinct peaks, one above the Lino Gray Complex
material in the eastern trenches, 17 and 18, and one above the western
trench 3, connected by a fairly level top surface lower than either but
marked by a distinct dip downward into a pit in trenches 11 and 12.
Section 4 shows the Lino Gray Complex of the eastern trenches covered
over with a layer of Red Mesa Complex material, which sinks downward
in trench 14 to the level of the Lino Gray Complex but rises again to
form the highest peak found for the Red Mesa Complex. This peak
is in trench 15, near the western edge of the dump. Section 4 covered
the highest surface of the dump.

In section 5 the Red Mesa Complex refuse lies as a long layer, thinner
than previously, and dipping toward the west, where it covers the

south end of the low Lino Gray Complex mound, and in section 6 it
shrinks to an even thinner layer, covering small Lino Gray Complex
mounds in trenches 7 and 15, and shrinking yet again in section 7.
Evidently the refuse of the Red Mesa Complex formed an irregular
mound overlying a Lino Gray Complex mound on the east, a smaller
Lino Gray Complex mound on the west, and one very small deposit of
it just south of the center. With these exceptions Red Mesa Complex
refuse formed the lower layer of the large mound, extending to the
north of section 1 but almost at an edge to the south in section 7, with
its peak in section 4. In bulk it could have contained little less material
than the refuse of the Escavada Complex which overlay it.

Escavada Pottery Complex.—This mound, apparently started from
Bc 50, showed two peaks in section 2, three peaks in section 3, its
highest central point in section 4, and a fairly level diminution through
sections 5, 6, and 7.

General Discussion.—Some of the Lino Gray Complex levels in
the dump show so few sherds that it seems probable that we are
examining a Lino Gray Complex surface level rather than a real
mound. The sherds representing this period are always imbedded in
adobe, showing some charcoal but little ash, the ash probably having
been leached out since deposition. The sherds, ash, and charcoal may
have been cut into the adobe by surface wash. The levels of Red
Mesa and Escavada Complexes show as one thick deposit of household
sweepings, sand, charcoal, ash, bones, sherds, and other cultural
material. Within this deposit, lenses and strata may be distinguished
by minor variations in color and small differences in composition. The
interpretation of these irregular strata, whether significant of culture
period or of subdivisions of time within a period, when the people
may have used various sections of a dump successively, or whether
significant of weather fluctuations, are discussed (for section 6) in
Part II, B.

The Lino Gray Complex mounds suggest that the refuse was
thrown out from individual pit houses, but the relatively even distribution
of the upper material from east to west indicated the probability
that refuse was thrown out onto the common dump from both Bc 50
and Bc 51 during the periods of which the Red Mesa and Escavada
Complexes may be diagnostic.

Section B

THE RELATION BETWEEN CULTURAL LEVELS AND
SOIL STRATA IN THE REFUSE MOUND

By Donovan Senter

In the refuse dump[9] natural strata show up in the cross-section
profiles (see Fig. 2). These strata appear to be of different types of deposit,
although all contain more or less ash, charcoal, bones, potsherds,
and cultural material of other types. In view of the work done in
1936,[10] it was felt that there might be a possibility of relating these
changes in appearance of deposition to the general changes in deposition
in the canyon over a long period of years. At all times, it was kept
in mind that these strata might be, however, merely artificially
produced by changes in the type of material thrown upon the dump
and by cloudbursts or floods.

The weather fluctuations shown for the canyon in the tree ring
chart, and responsible for the various levels of deposition and of
erosion shown on the cut taken near Chetro Ketl,[11] were taking place
at the time these two small ruins were occupied, perhaps 800 to 1080
A. D., and while their dump was being laid down. Indeed, both the
observed evidence and a priori considerations suggest that, although
the greater part of this dump material was artificially laid, sandstorms,
sheet wash, and erosion affected the surfaces of the artificial deposition
as it grew up year by year. One might think of the household
debris as sometimes being sandwiched in between the various thin
natural deposits from heavy sandstorms and torrential rains, and at
other times as being modified by other erosion. The total amount of
erosion and of deposition depended mainly upon the weather fluctuations.
The principal question which arose concerning the demarcation of
natural strata was whether any particular line of demarcation was
cultural or natural, that is, whether these strata indicated cultural
divisions, weather fluctuations, or both.

The Situation.—This dump rests upon a low ridge which runs
directly out from a point of carboniferous shale of the Allison series,

which underlies a cliff of Chacra sandstone. From the base of this
cliff the sheet wash of torrential rains, which are (now, at least)
common in Southwestern summers, spreads out over the dump surface,
the wash flowing principally toward the north in the direction of the
canyon bottom and secondarily toward the eastern and the western
edges of the mound, which probably were slightly lower than the
central area. The household refuse, with its basis of sand and ash, is
soft, lacks compactness, and is easily cut by water, and the presence
within the deposits of sherds, small pieces of sandstone, bone, etc.,
further prevents packing and exaggerates the tendency toward erosion.
A refuse mound located on flat ground or rising in a considerable
peak above the surrounding surface would be more or less equally
eroded from all sides and the lighter material from the peak of all
the lower slopes. A mound, however, which is only slightly rounded
on top and which slopes as a whole in the direction naturally taken
by runoff flowing toward the canyon floor[12] is washed principally from
one direction, and the lower side receives the accumulation washed from
the area behind it. Thus we have a constant washing northward of
sand, charcoal, the light weight sherds, and especially ash from the
more southern lenses of dumped refuse. Naturally, the lighter substances
like charcoal, if not trampled into the surface and crushed,
would be subjected to movement by a minimum of natural force (wind
or water). Similarly there is, in general, a continuous process of
migration of sherds downward into the underlying strata, for as the
sand and ash are washed from beneath and around the sherds, those
too heavy to be carried with the rivulet must sink (or be trampled in
wet soil) to the bottom of the cut.

A further dumping of refuse fills up the cuts and elevates the
ground surface, but the next storm will slightly pack and lower this
surface and introduce new cuts and rivulets. The sherds of different
periods are mixed northward and downward in movements stimulated
by natural forces. The areas most affected are those farthest north,
which have received the full brunt of both processes for perhaps a
thousand years, possibly two hundred or more during occupation of the
mounds and probably about eight hundred since. Similarly, those
farthest to the south are least mixed by washing and should give the
most dependable records of pottery type complexes and percentages
available in this refuse mound.[13]

Method.—Section 6 (see Fig. 1) of the refuse mound was about
midway between the northern and the southern extremities. This
long east-to-west cut provided opportunity for study of the appearance,
composition, and dip of the succession of strata making up the dump at
this longitude. These strata were traced and were drawn on coördinate
paper (see Fig. 3), each stratum being marked for composition
and general appearance, and photographs were taken. From trenches
3, 7, 11, and 15 the columns were removed in 6″ arbitrary levels,
and from the area near the walls of Bc 51 at the eastern end of the
trench a column was removed by natural strata or levels. In both
cases the material was screened for sherds and for other cultural
material. All sherds were washed, classified in the field laboratory,
percentages taken, and the results tabulated on the drawing of the
strata of the trench. Rarely did the line of the natural strata cross
near the center of an arbitrary level, but in those exceptional cases
the percentages for that arbitrary level were not used in averages
for either stratum. Where the line of the arbitrary level crossed
near either extremity of the natural strata, the percentages were
averaged with those of the stratum of which it was largely a part.
The removal of natural strata from a column which had been isolated
so that the dip of strata in the deposit could be observed on all sides
was not tried. The strata were numbered down from the top, although
all were not present in every part of the cross-section.

Results.—Stratum I, described as humus, organic material, sand,
charcoal, and sherds, was light in color and heavily permeated with
sand. The bottom of this stratum ran from four inches to a foot
below the present surface and was easily distinguishable from the
stratum below as being softer, although the general composition of
both was similar. This upper stratum appeared to consist entirely of
material which had washed from the southern surface of the dump
and had covered over the original surface of this central section.
The sherd complex found within it, then, might be expected to be
somewhat mixed but in general to represent as late or perhaps a later
period of deposition than the complex of the stratum immediately
under it.

Stratum II, described as sand, charcoal, sherds, and cultural
material, is separated from the upper stratum in places by occasional
stringers of sand which washed or blew over it before the heavy
wash from above covered it over. In other places the two merge, almost
imperceptibly. The second layer is slightly darker in color than the
first and shows scattered lenses of ash and of charcoal.

The sherd composition of the two may be compared in Table 1. It is
apparent that Strata I and II are made up of essentially the same
complex of sherds and that in many cases a type holds the same relative
place in both strata.

Table 1
SHERD PERCENTAGES OF THE REFUSE MOUND BY STRATA
(Section 6) Trenches 3, 7, 11, 15

                               

	Stratum	Stratum	Stratum	Stratum	Stratum V
	I	II	III	IV	A	B
Lino Gray	28.7	22.9	53.1	69.4	72.3	100.0
Exuberant Cor.	19.4	23.2	13.6	1.6	3.2
Gallup B on W	16.7	10.6	5.1	4.7	3.4
Escavada B on W	13.6	19.3	10.5	7.0	13.7
Red Mesa B on W	9.0	16.8	14.4	10.1	3.2
Chaco Cor.	4.5		.8	.3
Kana-a Gray	4.4	2.2	.5	2.2	5.1
Chaco B on W	1.0	.9		.3
McElmo B on W	.9	1.6	.9	.4
Wingate B on R	.6	1.7	.2	.5
Deadman's B on R	.4	.8	.2	.3	3.2
Sunset Red	.2	.7
Kana-a B on W	.2	.1	.5
Total number of sherds in sample	276	1592	239	379	61	8

The most plausible inference which, it would seem, might be
drawn from these facts is that of but a short difference in time[14]
between deposition of the two strata, both perhaps representing one
culture period which it is tempting to identify with "Pueblo II." The
upper stratum shows decrease of Red Mesa Black on White, and the
three trade types, Deadman's Black on Red, Sunset Red, and Kana-a
Black on White; and an increase of Gallup Black on White and the appearance
of Chaco Black on White and Chaco Corrugated. The rise and
fall of types within a span of over more than one period or even within
the same culture period is to be expected, but the consistent rise and
fall of more than one type might be considered a good criterion of some
distinction in time, and here the upper stratum would appear not only
to have been washed over the other but to have been orginally deposited
later than the other.

Stratum III, found only on the east end of the dump, is of the same
composition as II, although of slightly darker color, but its pattern
complex is similar to that of Stratum IV, not to that of Stratum II
(see Table I).

Stratum IV (see Table I) is described as composed of sand, charcoal,
clay, and cultural material, and it varied but little in color from
Strata II and III above it. As in the other strata Lino Gray is preponderant,
Red Mesa Black on White and Escavada Black on White hold

second and third places. Gallup Black on White holds fourth place
and Kana-a Gray and Exuberant Corrugated are barely represented.
It is interesting to note that Kana-a Gray was seventh in Stratum I,
ninth in Stratum III, fifth in Stratum IV, and third in Stratum V.
Stratum IV would appear to represent mixed debris slightly earlier
than Stratum III and directly overlying Stratum V, which shows,
perhaps, an earlier but mixed representation of much the same period.

Stratum V is made up of charcoal, clay, sand, and cultural
material, but the sand is less in proportion than above. By cultural
material and sometimes by appearance it is divided into 2 parts,
A and B. Stratum V (see Table I) in section 6 shows a heterogeneous
pottery complex, the upper section, A, being Red Mesa Complex, and
the lower section, B, being 100% Lino Gray.

The lowest level of section 6 represents probably the natural
ground surface at the time of the Lino Gray Complex occupation, but
was not a dump. Sherds from the Red Mesa Complex dump, just to
the south and higher, washed over it and were later mixed with other
sherds from a later part of the same period. This later material was
finally covered over with sherds. The small sherd totals, ranging
from 8 to 61 in the lower levels in this section, suggest that it was
not used to any extent as a dump area until the final occupation of
the site. The sherds would have been washed and tramped into the
surface clay, which became mixed to some extent with small deposits
of ash and of charcoal.

The sherd complexes within a natural stratum were found to run
fairly consistently through the center of section 6, so it was decided to
test this area further. Near the walls of Bc 51 in trench 34, and 42′
east of trench 15, a column 3′ square was isolated on two sides. These
profiles were studied as a preparation for removal by natural levels.
Each stratum was removed by troweling, the sherds taken out by
hand, and the material from each was classified separately. Profile
Strata I and II were taken off as units, but Stratum III was divided
into two layers, A and B. A showed natural deposition of sand within
the cultural deposition. It contained considerable charcoal. Layer
B was of less laminated sand with a little charcoal at the bottom.
Strata IV and V were not removed. The percentages for the various
strata follow:

TRENCH 34

                             

	Stratum	Stratum	Stratum III
	I	II	A	B	A & B[15]
Exuberant Cor.	49.0	42.0	20	34.5	27.3
Escavada B on W	25.0	19.0	30	27.0	28.5
Lino Gray	7.5	16.5	10	16.6	13.3
Gallup B on W	8.0	5.8	10	14.0	12.0
Chaco Cor.	1.0		30	1.0	15.5
Red Mesa B on W	2.5	2.8		4.7	2.4
Deadman's B on R	.62	2.0		1.2	.6
Chaco B on W	.62	1.8
McElmo B on W	3.4	1.3
Kana-a Gray		1.3
Wingate B on R	.31	1.3
Flagstaff Red	.93
	323	223	10	84	94

One first notices that the percentages in this test do not at all
agree with those running consistently through the same strata in
the center of section 6. It is apparent that the prevailing type in
the column is Exuberant Corrugated with Escavada Black on White a
good second, and Lino Gray third. The fact that Gallup Black on White
and Chaco Corrugated are more prevalent in the lower levels might
indicate some accidental reversal of stratigraphy due to the building
of the nearby kiva or the disturbance caused by the nearby
burial Bc 51 60/31.

The one point which is apparent from comparison of the sherd
complexes and proportions taken from this test near the rooms with
those taken from the same natural strata toward the center of the
dump is that the same strata at two different points do not contain
the same relative amounts of single types or of groups of types.
These natural strata are traceable from one end of the dump to the
other on the face of an east to west profile revealed on the south side
of section 6. The area of Strata I and II, which lies toward the center
of the dump shows a consistent sherd complex, but the eastern ends of
the same strata give a different complex, perhaps later.

Conclusions.—If the strata in the dump do not include throughout
cultural material of the same period, how can these division lines be
accounted for?

At the base of the dump is a layer preponderantly of early material,
Stratum V. This is a thin stratum largely composed of clay
but mixed with some sand and a little ash, some charcoal, and a
scattering of sherds. The sherd totals are scarcely enough to warrant
calling this layer dump material. Small deposits of ash, charcoal

and sand accumulated on the surface were trampled and washed into
the clay and gradually built up the surface to an average depth of 6″.
Then, upon this hard base, a people began to throw their trash in such
amounts that a dump of daily sweepings began to rise, Stratum IV.
Its lenses and pockets resembled those of the later Strata I and II.
Its composition differed from that of the hard cumulative surface of
adobe below which contained sherds. One was an occupational surface
and the other was an actual trash mound. Stratum III, seen only in
the eastern section of the dump, accumulated over trash but was
slightly later, the sherd complexes being very similar.

The transition in pottery and in house types perhaps took place
around the middle of the 9th century. In this case the severe drouth of
900 to 907 A. D. would have come not long after this transition. The
succeeding erosion period which cut the surface of the canyon, and
would likewise affect the surface of the dump, was hypothetically
traced in erosion surface number 1 in the trench sunk near Chetro
Ketl in 1936. It seems quite possible that the upper limiting line
between Strata III, IV and Stratum II was caused by the erosion after
this drouth and is comparable to erosion surface 1 of the Chetro
Ketl cut.

A highly tentative interpretation follows: The upper levels of the
central area of Stratum IV show high percentages of the Red Mesa
Pottery Complex types, so much so that in drawing the cultural divisions
of the dump by pottery alone, the line between the Red Mesa and
Escavada Complexes is some inches below that drawn by the top of
natural Stratum IV (see Fig. 2). Examinations of the sherd complex
and percentages given for Stratum IV show far from a pure Red
Mesa Complex. Stratum III likewise shows considerable Escavada
Complex material. If the Red Mesa Complex dump grew up to make
most of Stratum IV, which was completed by debris of early Escavada
Complex, and then the surface was badly cut by the erosion following
the drouth of 900 to 907 A. D., we would find the Escavada Complex
sherds partially cut into the Red Mesa Complex material by wash.
Thus, in taking the entire Stratum IV together for sherd percentages,
we would expect just the confusion of Red Mesa and Escavada complexes
which we do find, a confusion of complex much greater than any
found in the Escavada Complex Strata I and II.

The division line between Strata III and IV, both of Escavada Complex
material, may very possibly have been caused by rains beating on
the central section of the dump for some years while the people threw
their trash farther to the north or to the south. Stratum III does not
extend farther to the north or to the south. Stratum III does not extend
farther westward than trench 14 and hence could have been, in this
section, of only temporary use. Later the people again used the

central and western parts of the dump for deposition and thus laid
down Stratum I.

The prehistoric people presumably, in the modern Pueblo manner,
used different areas of the mound surface at different times as
depository for their household trash. Material washing from one
area onto another would more or less modify the original complex of
both areas.

Strata II and III are similar to each other in composition and differ
from Stratum I, the surface soil, in being harder, showing fewer streaks
of sand,[16] and in having more undisturbed lenses of household debris.
Yet Stratum III represents the Red Mesa Complex, and Strata I and
II represent the Escavada Complex.

Stratum I, the surface layer, is obviously disturbed and may owe
its color, its looseness, and its stringers of sand to the sheet wash, the
sand storms and the other disturbances which have passed since the
last household debris was deposited on the mound. The drouth of
1035 to 1041 and its attendant erosion period must have cut the dump
surface while Bc 51 was still occupied to some extent, but its effects
would have disappeared in the surface erosion since that time.

Section C

A NOTE ON STRUCTURES OF THE REFUSE MOUND

By Clyde Kluckhohn

Since the structures discovered in the refuse mound up to the
close of the 1937 season had either been partially excavated under
other supervision prior to the beginning or were found at the very
close of that season, not even a proper "preliminary report" can be
presented here. A note, however, embodying the most general facts
may be useful in estimating the general situation at Bc 50-51.

Pithouses.—Toward the close of the 1936 excavations a pithouse
was partially uncovered in trenches 16, 17, and 18 of sections 1, 2,
and 3 (see Map 1). This pithouse was further excavated in May,
1937, by a party of students from the University of New Mexico
working under the direction of Wesley Bliss, and superposed slab-lined
cists were also discovered. Additional excavation during August,
1937, was likewise under the immediate supervision of Mr. Bliss, and
his drawing (Fig. 4) shows the principal architectural details. Since
the writer has not had access to Mr. Bliss' field notes, further information
cannot be given except to state that the 35 sherds found in what
Mr. Bliss considered the "entrance" yielded the following percentages:
Lino Gray, 40; Escavada Black on White, 29; Kana-a Gray, 11; Exuberant
Corrugated, 8; Red Mesa Black on White, 8; Wingate Black
on Red, 3. A sherd sample of 27 from the floor of the pithouse proper
showed these percentages: Lino, 52; Red Mesa, 25; Exuberant, 18;
Escavada, 4. The Fugitive Red jar neck shown in Plate 8D was also
found on the floor of this pithouse.

In trench 3, section 6, a hard clay deposit was encountered at a
depth of 30″ beneath the surface. This clay was notably sterile save
for minute amounts of charcoal and excessively rare sherds which (so
far as found) were exclusively of Lino Gray. Subsequent excavation
showed that a pit (now filled with later refuse) had been dug into this
clay layer. (See Map 1, and Plate 5A).[17] A "scoop" metate was
found slightly above the floor level in the pit,[18] and the floor fill yielded
18 sherds in the following percentages: Escavada,[19] 33; Lino, 28; La
Plata Black on White, 17; Red Mesa, 5; Exuberant, 5; McElmo, 5;

Figure 4—Pithouse and Slab-lined Cists in Sections 1, 2, and 3, Refuse Mound

Sandstone Black on Orange, 5. It was not possible to complete excavation
of this pit before the end of the season.

In trenches 16 and 17 of sections 4, 5, and 6 a pit apparently of
approximately the same shape was partially outlined during the
final days of the 1937 season. A portion of the floor fill excavated in
trench 16 of section 6 produced 62 sherds in the following percentages:
Lino, 79; Red Mesa, 11; Exuberant, 5; La Plata, 2.

Walls of Unfamiliar Type.—On the last day of the excavation in
trench 24 a low wall was found extending diagonally across section 6.
This wall was built of dressed slabs, non-dressed boulders, and small
stones set in abundant mortar. At about the same time circular walls
of essentially similar construction were discovered in a western extension
of section 6, 16′ 1″ and 24′ 10″ west of the western border of
trench 1. The former of these was about 3′ below the surface, atop
the sterile clay layer. The latter was nearly 3′ lower in another pit
which had apparently been dug into the clay at this locus.

These walls do not appear to fall into any of the previously recognized
Chaco Canyon masonry types. Naturally, the evidence is insufficient,
but it may not be out of place to record the speculation that
they are representative of a time of experimentation in dwelling construction.[20]
From their position and general character these problematical
structures may possibly represent a period after the abandonment
of the pithouses or a period of transition from pit to abovesurface
structures. Perhaps slabs (so often used to line pithouses)
were carried over into surface dwellings but the as yet inexperienced
masons were forced to use much mortar and the reinforcement of
boulders to provide any stability. The 18 sherds in immediate association
with the walls in trench 24 showed the following percentages:
Lino, 67; La Plata, 28; Wingate, 5. Sherds associated with the walls
of this type to the west gave highly similar figures, and provide a
strong suggestion that the builders of these walls had a culture of
which the Lino Gray pottery complex may be diagnostic.

Cists.—For the slab-lined cists excavated by Mr. Bliss see Fig. 4.
The cist enclosing burial 60/31 is shown in Plate 4 before and after
removal of the cover which was composed of 4 major stone slabs,
one of them a "scoop" metate. Evidences of 3 lengthwise pieces of
cottonwood and of one crosswise piece were also found. The fill
around the burial was notable for its relative lack of sherd and other
refuse material. A few bones of small rodents were found within the
cist. Decayed roots were observed, some of which penetrated the
human bones. The latter were unusually disintegrated, probably
because water draining into the cist would tend to remain because of
the especially hard texture of the floor. The strata immediately

above and surrounding the cist appeared to be continuous and undisturbed.
All in all, the evidence seemed to suggest that the cist had
been left exposed above the ground (or was a very shallow interment
like many of the refuse burials) and that the fill covering it had been
placed by wind and rain.

About 16″ above this cist was a layer (varying from ½″ to 1″
thick) of stone chips which could be traced on continuous distribution
at this level above this portion of the refuse mound (and as far south
as Sect. 9) over to the northern walls of Bc 51. Careful examination
of the contents of this layer and of its location and extent suggested
that it resulted from the building of some or all of these northern
rooms. Much of this sandstone layer was fairly well pulverized.
The distribution of chips in the layer was very similar to that in deposits
adjacent to the walls of Pueblo Bonito where Navaho workmen
have recently been repairing walls. The deposit here seemed too
extensive to represent merely repair, but this possibility cannot, of
course, be disregarded. On the whole, however, it seems most likely
from its position beneath the probable construction level that the cist
is of a period prior to the building of some, at least, of the northern
rooms of Bc 51.

Discussion.—As is evident from the foregoing, most of these structures
were discovered so late in the 1937 season that it is not possible
to do more than report upon their discovery and relative position.
From the data of superposition and stratigraphy it seems probable
that pits, walls, and cists represent sequential periods in that order.
But this must be regarded purely as a highly tentative interim communication.
The scrupulous excavation of these structures of the
refuse mound and their relationship to the clay layer (and the shale
which often overlays it, particularly to the west) and to soil profiles
generally, formed the principal problem of the 1938 excavations under
the direction of Dr. A. R. Kelly.