37
III. RADIOCARBON DATES FROM COPAN, HONDURAS
John A. Graham and Rainer Berger
The Maya ruins of Copan, located in western Honduras, lie on the very
frontier of Classic Maya civilization. In spite of their peripheral situa-
tion, however, few indications of a frontier settlement are evident in the
known remains which constitute one of the finest exponents of Classic Maya
civilization (1). Extremely fine architecture and sculpture eloquently
testify to the brilliance of the Copanec artists while the rich corpus of
hieroglyphic inscriptions has frequently been interpreted to mark Copan
as an intellectual leader among Maya communities. Although an intensive
aspect of the Classic Maya tradition, the material expression of Copan cul-
ture is highly distinctive and testifies to the originality of its artists
and the sophistication of their patrons. Perhaps the individuality of
Copan derives in part from its frontier location even though the cultures
beyond were only the palest reflections of the greater Maya splendor. And
more likely, the wealth of Copan derived in part from international commerce
and from its closely related role as a great center of pilgrimage (the
ancient antecedent to Esquipulas?).
Although careful and painstaking research has been carried out in the
Copan valley by a number of archaeological expeditions from Carnegie Insti-
tution of Washington, and earlier by Peabody Museum of Harvard, the magni-
tude of the task of recovering Copanec history is so great that many years
of work remain to be completed before an adequate knowledge of the valley
is obtained.
A preceramic occupation in the valley of Copan has been suggested but
thus far remains to be confirmed and elucidated. Preclassic activities in
the valley are more definitely established by several battered sculptures of
quite early style as well as by good ceramic evidence. Although the nature
and extent of the Preclassic occupation remains unknown, it was probably of
Considerable importance; the general impression of a rather scanty and
Uncomplicated Preclassic very likely derives from its obscuration and dis-
tUrbance by the intensity of Classic Period use of the valley.   Considerable
Early Classic activity in the valley is well evidenced although it is the
38
fine Late Classic remains which have received most of our archaeological
attention, partly because of their great accessibility at the main site of
Copan. Although Classic standards of sculptural and inscriptional activity
came to an end early in the ninth century, Postclassic occupation of the
valley is established but is little known.
Since the ceramic, architectural, and sculptural aspects of Copanec
cultural development are so highly distinctive and individual, only general-
ized features of these traditions can be correlated with the comparable
developmental histories defined nearer the center of the Classic Maya heart-
land, and the basis of a more precise chronology for Copan's history has
depended upon interpretation of the Classic period hieroglyphic dates. With
this situation in mind, and as no radiocarbon age measurements were available
for the southwestern region of Classic Maya civilization, an effort was made
to collect suitable carbon samples for dating when R. F. Heizer, P. Drucker,
H. Williams, and J. Graham visited Copan briefly during the course of
archaeological research in southern Mesoamerica in 1967. Additional samples
and data were collected by J. D. Clark and J. Graham in 1969. Our brief
researches at Copan were greatly facilitated by the kindness and attentions
of Dr. Jesus Nunez Chinchilla, Director of the Instituto Nacional de Antropo-
logia in Tegucigalpa, while financial support and technical assistance were
provided by the Archaeological Research Facility of the University of Cali-
fornia, Berkeley.
One of the finest examples of Copan architecture is Mound 26 or the
"Temple of the Hieroglyphic Stairway." Although only a small portion of the
elaborately sculptured sanctuary, or temple proper, has survived, the
approximately ninety feet high pyramidal substructure is famous for its
magnificent hieroglyphic stairway. In addition to an ornamentation of various
fine sculptures, some sixty odd risers of the stairway were carved with
hieroglyphs to form the most extensive glyphic inscription to be preserved to
us. Morley has suggested that work on the stairway may have begun shortly
after A.D. 700 (2), and the epigraphic evidence strongly indicates dedication
of the stairway very near A.D. 750. Stela M, erected immediately in front and
centered upon the stairway, is inscribed with the certain dedicatory date of
A.D. 756 (GMT correlation; Maya Long Count date 9.16.5.0.0).
39
During archaeological excavations on behalf of the Carnegie Institu-
tion of Washington in 1936, Gustav Stromsvik (3) opened a tunnel ("Copan
Tunnel 2") through the base of Mound 26 along a west to east axis beginning
just south of the hieroglyphic stairway. The tunnel encountered various
stages of earlier construction buried by later activities before sloping
downward to reach a basal deposit of naturally laid, dark gray fine silt
containing some stream cobbles and which apparently represents floodplain
deposits of the Copan river. Upon this sterile deposit the tunnel exposed
a thin midden level containing sherds, charcoal, and animal bones. Dating
of this pre-Mound 26 midden deposit has rested upon Longyear's identifica-
tion of one or two sherds as "definitely Early Classic" (4).
Our first carbon sample consists of mixed earth and charcoal from
the midden exposed at the very end of the tunnel. The radiocarbon age of
1700 + 110 years, or about A.D. 250, is in excellent agreement with the
available archaeological evidence and indicates an early Early Classic date
for the sub-mound midden.
Our second sample, UCLA-1420, consists of charcoal removed from a
floor matrix beneath, and associated with, the latest interior architecture
exposed by the tunnel. The measured radiocarbon age of 1200 + 70 years is
to be adjusted to A.D. 600, 700, or 800 to correct for secular variations (5).
Based upon stratigraphy, UCLA-1420 should date later than the pre-mound
midden deposit placed at A.D. 250 + 110 years by our first sample; similarly,
it should date earlier than the age of the final construction of the hiero-
glyphic stairway which was completed about A.D. 750. Thus, the age of the
second sample seems best at A.D. 600, with A.D. 700 being possible but less
probable, and A.D. 800 being impossible.
In conclusion, the radiocarbon age measurements reported here~ are the
first to be obtained for archaeological materials from the Copan area.   Their
ages are in excellent agreement with the current archaeological chronology
and interpretation of Classic period Copan history. In addition the sample
UCLA-1420 provides evidence from the southwestern corner of the Classic Maya
realm bearing upon the European-Maya calendar correleation. With Stela M
40
securely dated at 9.16.5.0.0 in Maya chronology, a 12.9.0.0.0 or Spinden
("type A") correlation placing Stela M at about A.D. 500 is definitely incom-
patible with the indicated age of the latest pre-hieroglyphic stairway
substructure architecture. The radiocarbon age is in agreement with an
11.16.0.0.0 or other later equation (6).
Bibliography and Notes
1. T. Proskouriakoff, "An Album of Maya Architecture," Carnegie
Inst. Wash. Publ. 558, 31-49 (1946).
2. S. G. Morley, "The Inscriptions at Copan," Carnegie Inst. Wash.
Publ. 219, 272 (1920).
3. G. Stromsvik, in "Year Book No. 35," Carnegie Inst. Wash., 118
(1936); G. Stromsvik, "Guide Book to the Ruins of Copan," Carnegie Inst. Wash.
Publ. 577, 71-72 (1947).
4.  J. M. Longyear, "Copan Ceramics, a Study of Southeastern Maya
Pottery," Carnegie Inst. Wash. Publ. 597, 19 (1952).
5.  H. E. Suess, I. Geophys, Res. 70, 5937-5952 (1965).
6. Supported in part by the National Science Foundation , GA 4349,
and by the Archaeological Research Facility of the University of California,
Berkeley.