Stross, Fred H.

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Lawrence Berkeley National LaboratoryRecent WorkTitleMAYAN OBSIDIAN TRADE IN SOUTHERN BELIZEPermalinkhttps://escholarship.org/uc/item/6957991sAuthorStross, Fred H.Publication Date1976-02-01eScholarship.org Powered by the California Digital LibraryUniversity of CaliforniaI -..) .J Submitted to Science J . -~. LBL-5220 ' Preprint f' · MAYAN OBSIDIAN TRADE IN SOUTHERN BELIZE Fred H. Stross, Harry R. Bowman, Helen V. Michel, Frank Asaro, and Norman Hammond j ' .. '· l February 1976 '' \9"1 ~·. ' ' .... ~ . I • .~ -:'" :.I Prepared for the U. S. Energy Research and Development Administration under Contract W -7405-ENG-48 for Reference Not to be taken fll'om this room t" 0;1 t"l I U1 N N no .--DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of Califomia. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of Califomia. r 0 0 - 0 ~J u 4 5 0 I 2 1 s I ~ MAYAN OBSIDIAN TRADE IN SOUTHERN BELIZE by Fred H. Stross, Harry R. Bowman, Helen V. Michel, Frank Asaro and Norman Hammond Lawrence Berkeley Laboratory University of California Berkeley, California 94720 LBL-5220 () 0 ~ l D -1-Mayan Obsidian Trade in Southern Belize* Abstract. Precise neutron activation analysis has been done on the mesoamerican obsidian from Ixtepeque and El Chayal which are thought to be the major sourc:es of volcanic glass artifacts in pre-Columbian times. These results are compared with obsidian artifacts from Lubaantun, Wild Cane Cay, Frenchman's Cay and Moho Cay. Four years ago, one of us (N. H.) sketched a skeletal model for "Obsidian trade routes in the Mayan Area" (1), based on the source attribution of small numbers of obsidian artifacts from 23 archaeological sites of the Classic period (A.D. 300-900) in the Yucatan Peninsula and the highlands of Guatemala. Recently, 48 obsidian artifacts from sltes in Southern Belize (British Honduras) have been chemically analyzed by precise methods of neutron activation analysis (2), and ,the origin of nearly all of the obsidian could thus be determined with certainty. Some of the artifacts were recovered in the excavations of the joint Cambridge-Harvard projects at Lubaantun, a small major ceremonial center on the southeastern slope of the Maya Mountains some 25 km from the Carribean coast. Others came from surface collection from three of the off-shore coral cays of which the sample from Wild Cane Cay (23 blades) was comparable to that from Lubaantun (22 blades). Samples from Frenchman's Cay and Moho Cay (2 blades) were small. The Lubaantun th th site is known to have been occupied only in the 7 -9 centuries A.D. (the Late Classic period), while Wild Cane Cay was occupied from the -2-Late Classic through the Postclassic (A.D. 900-1500). No dating estimates are available for the other two sites, although Late Classic ceramics have been found in Frenchman's Cay. The sensitivity and precision obtainable by .neutron activation analysis made a study of source homogeneity attractive, and the two sources of obsidian that are thought to have been the major suppliers of the volcanic glass in pre-Columbian times, El Chayal and Ixtepeque, were studied in some detail, especially'the former. In this paper the results are summarized, to provide a solid basis for comparison with the artifacts. The El Chayal source samples were collected by one of the authors (F. H. s.) from road cuts at about 23, 24, and 25 krn northwest of Guatemala City. The Ixtepeque samples are part of the collection of the Archaeological Research Facility at u. c. Berkeley. These samples had been analyzed by neutron activation (3) prior to the present work. In the neutron activation measurements about 50 elements were searched for, and over 30 observed. Of these elements the ten that best distinguish the Ixtepeque and El Chayal sources are shown in Figs. 1, 2, and 3. Any one of these elements is adequate to distinguish between El Chayal and Ixtepeque Obsidian. i ', As an example of the reproducibility of the measurements, for the 16 most ~ecisely measured elements it was found (3) that the averaqe root-mean-square deviation was 1.5 percent for 12 El Chayal source samples from two of the road cuts (24 and 25 km), and 1.6 percent for the four samples collected from the other road cut (23 krn). With this precision there are considerable differences in chemical 0 0 u ~~~ 5 ' ' ') •'} 4 7 ~ u " ... -3-composition between.the obsidians from the road cut 23 km and the two 24-25 km northwest of from Guatemala City. Those artifacts, attributed to El Chaya~match the latter obsidian source rocks rather closely. Small differences, however, were observed, the largest being in the scandium abundance (about 5 percent). These differences probabiy indicate that the artifacts from El Chayal do not come from the same part of the deposit as our El Chayal sourc~ samples. The analytical results may be summarized as follows:. Of the 23 samples from Wild Cane Cay, 19 are ass·ignable to the Ixtepeque source, and four to El Chayal. Of the 22 samples from Lubaantun, 21 can be assigned to El Chayal, and one sample matches very closely in composition two obsidian blades from Ucareo, Michoacan (Mexico). For 20 elements the average difference in abundance for the two blades from Ucareo is only 3.4 percent, and the difference between these and the artifact from Lubaantun is only 3.3 percent. Thus the three artifacts undoubtedly came from the same source although we do not know its location. The previous model (1) predicted that obsidian at the Lubaantun site shou!d derive from both the El Chayal and Ixtepeque sources. This was only partly correct as none of the 22 Lubaantun artifacts examined . .• derives from Iextepeque. The fact that 95 percent of the specimens come from the El-Chayal source, however, does indicate that a route from southern Belize to the Alta Verapaz ftighlands in Guatemala (the "cacao route") was probably functioning in the Late Classic period (5). -4-The obsidian from Wild· Cane Cay derives from Ixtepeque (82 percent) and from El Chayal (18 percent), indicating that the coastal and overland trade routes network linked up at this ~deal natural harbour. Its nodal function in Mayan trade is confirmed by the quantities of exotic materials, including jade, Plumbate and Tulum Red pottery, and copper artifacts found on site, even though it is structurally unimpressive and physically tiny (4). Presence of these materials implies trade contacts from northern Yucatan to the Pacific coast of Guatemala. The pattern of obsidian sources attribution at Wild Cane Cay is approximately that predicted (1) for Lubaantun. It would thus seem that the conjunction of the trade networks lay not at the ceremonial center but at the subsidiary location where the large coasting canoes and the smaller river vessels could meet. Whether Wild. Cane Cay operated as a "trading port" or a "port-of-trade" in the Classic Period, in the manner that Sabloff and Rathje (6) have suggested for the island of Cozumel in the post Classic Period, is a problem that only further research can elucidate. Lawrence Berkeley Laboratory University of California Berkeley, CA 94720 Fred H. Stress', Harry R. Bowman, Helen v. Michel, Frank Asaro and ** Norman Hammond ) . -/ 0 0 ,~" -to 0 I ') ,;.t 8 0 ~- •1 :.l cl.i ~ .... l .... -5-Acknowledgements We thank Mr. Lim Tek, supervisor of the Berkeley Triga Reactor, and his staff for the nuclear irradiations which made this work possible. Special thanks are due to Mr. Duane Mosier for electronic design and support and to Ms. Julie Rodriguez for technical assistance throughout preparation and analysis of the samples. References and Notes * Most of the neutron activation analyses and their interpretation were performed under the auspices of the u. s. Energy Research and Development Administration. ** Undergraduate School·of Studies in Archaeological Sciences, University of Bradford, Bradford, England. 1. N. Hammond, Science 178, 1092 (1972}. 2. H. R. Bowman, F. Asaro, and I. Perlman, Archaeometry 15, 123 (1973). 3. F. H. Stross, H. R. Bowman, and F. Asaro, unpublished work. 4. N. Hammond, Lubaantun: A Classic Maya Realm (Monographs of the Peabody Museum of Archaeology and Ethnology, 2, Harvard University, Cambridge, MA, 1975}. 5. N. Hammond, An Overland route between the Maya Highlands and Lowlands (Mesoamerican routes of communication and contact, T. Lee and c. Navarrete, eds., Papers of the New World Archaeology Foundation~ in press). 6. J. A. Sabloff and w. L. Rathje, Changing Pre-Columbian Commercial Patterns (Monographs of the Peabody Museum of Archaeology and Ethnology, Harvard University, Cambridge, MA). -6-Figure Captions Fig. 1. Selected chemical abundances of obsidian from Wild Cane Cay, Ixtepeque and El Chayal. All values are in parts-per-million except the iron abundance, which is in percent. The hatched areas show the root-mean-square deviation i~ the abundance values. The values in parentheses indicate the number of samples measured. 1st bar--Mean value and root-mean-square deviation for 4 source rocks from Ixtepeque volcano. 2nd bar--Same parameters as 1st bar for 19 obsidian artifacts from Wild Cane Cay. 3rd bar--Same parameters as 1st bar for 4 obsidian artifacts from Wild Cane Cay. 4th bar--Same parameters as 1st bar for 7 obsidian source rocks from a highway cut in the El Chayal deposit about 25 km NW at Guatemala City. Fig. 2. Selected chemical abundances of obsidian from Frenchman's Cay, Moho Cay, Ixtepeque and El Chayal. All values are in parts-per-million except the iron abundance, which is in percent. The hatched areas in bars 1, 3, and 4 represent the root-mean-square deviation in the abundances. The solid areas on the second bar show the error in a single measurement due to counting statistics. The values in parentheses indicate the number of samples measured. The data for the 1st and 4th bars are the same as in Fig. 1. Fig. 3. Selected chemical abundances of obsidian from Lubaantun, Ixtepeque, and El Chayal. The representation is very similar to Fig. 2. "' . --~m --.,_.:<..? X~ 1.0 1-...... 3: ~~ 0.5 -,.._ --~"016001-• >-uo ·~ uul I~,.., ~-400 LLJ ~fBI 200 liBIJ!!! 0 II I I I I II II 0 II I I I I II I I Iron (0/o) Manganese ~ ~ 6 -4 -:& !i:! 2 0 Cesium 121- 1 61- -1 .. pi!i! Br~fi!i!l1 0.5 4 O" Ill Ill II 0" Ill ""' Antimony Thorium 4 2 ~ .. .., ~f!ll 0 11 I I I I I I II Hafnium Fig. 1 ~ -0 6t -I C) 1.0 ~n :l~ fi!illf5!11 II Ill 0.5 Qlllll I I I II 0 .r•~ "'"" ... ... "!...:... v, C) ,,, '• Uranium Cobalt • f~' -J I ..t~~ "' 150t- ~~ 1.01 ~~ sq r-, 1 too~ fa 0.5 50 0 11 II I I I I II Tantalum 0 . . Rub1d 1um XBL 7511-9501 ..................... ......... ........... v-N "-'· ""-""'...._........... ......... ...=uu X•:E 0 ~1600 .... _LL. 1.0 r:~~ pel ~ <.J wj4QOI~F1 F fiZ 0.5 200 ffZ I&' 6 ... 1-4 ... !EIRJB! 2 Qll II I I I I II 0 II II II I I II 0 I I II I I I I II I ron ( 0/o) Manganese Cesium 0.8 1 ~· 0.6 0.4 0.2 0 Anttmony 12 t- ~ 6 ... -fS!i St-RAP: 4 0 Thortum I-4.RAII= 2 -piii 0 I I II I I I I I I Hafnium Fig. 2 6t- -4 ... 1- "' . 1.0~-ll! -2r"'Fl"" 0.5 -~ 0·· II I I I I I I 0 ,, II II l I II Uranium Cobalt 150 .... ~ 1.or R~F -~.100~,., ~ 0.5 50 0 ,, 11 11 1 1 ,, o·~ II II I I " Tantalum Rubidium XBL7511-9500 -I 00 I --- ..... V-=-................. ,_ ...,: m ~ ~1600 X::> _g ...,._JCDO" I.O filii ~ 3 wl400 F!FB 0.511 I '•' ' , , "200 I I I I II 0.0" Ir~n o/o 0 0.8 0.6 12 0.4 8 0.2 4 ~ ~ ~ ~ Manganese F r -~ ~ r p::a 0.0 Antimony 0 Thorium -~ ~ 0 !""" r-6 ~ 6 c ~"-~-1-4 - 4 c ..t..c = u·~ 2 2 ·~-... ~. ·......: I t>..;. 0 Cesium 0 Uranium Coba It ...0 I (!~ 0 6 1.0 4 2 0.5 0" I I I I I I II 00'1 I I I I I I II 0 Hafnium • Tantalum Rubidium XBL 7512-9593 Fig. 3 • • ~J .J • I r;his report~as ~~~::th -::;;:~ -irom :-United• ~t-:s Ener~ ;e~. ·1 ': search and Development Administration. Any conclusions or opinions expressed in this report represent solely those of the author(s) and not necessarily those of The Regents of the University of California, the 1 Lawrence Berkeley Laboratory or the United States Energy Research and Development Administration. .. 0.-TECHNICAL INFORMATION DIVISION LAWRENCE BERKELEY LABORATORY UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA 94720 "' .. -

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MAYAN OBSIDIAN TRADE IN SOUTHERN BELIZE

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MAYAN OBSIDIAN TRADE IN SOUTHERN BELIZE

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