Report to Consejo de Arqueología Instituto Nacional de Antropología e Historia: An Archaeological Investigation of Late Archaic Cerros de Trincheras Sites in Chihuahua, Mexico, Results of the 1998 Investigations

Cerro Juanaqueña is a large cerro de trincheras located in northwestern Chihuahua, in the municipio of Janos. The site was built over 3000 years ago on the summit and slopes of a 140 meter high basalt hill which overlooks the floodplain of the Rio Casas Grandes and its major tributary, the Rio San Pedro. Large constructed terraces cover an area of about 8 hectares, with over 8 kilometers of terrace wall and 108 stone circles (see Figure 1). A large number of stone artifacts are found with these features, and excavations have revealed rich midden deposits with abundant bone and carbonized plant material (Hard and Roney 1998a). In our 1998 informe (reporting results of our 1997 field season) we described test excavations in three terraces and four stone circles, as well as mapping activities, collection of surface materials, geomorphic investigations of the Rio Casas Grandes floodplain, documentation of rock art, and reconnaissance at other similar sites. This informe summarizes the investigations undertaken at Cerro Juanaqueña and other related sites under the oficio No. C.A. 401–36/560 (22 de mayo de 1998) authorized by the Consejo de Antropología. The project was funded in 1997 by National Science Foundation (NSF) SBR-97086210 and in 1998 by NSFSBR-9809839. Our primary objective during 1998 was to recover charcoal for radiocarbon dating and macrobotanical analysis, as well as to expand the sample of faunal materials. Our strategy was to select 10 terraces on Cerro Juanaqueña for test excavation. Descriptions of these excavations are in Appendix 1. We continued geomorphological investigations of floodplain deposits, which were begun in 1997, as well as in-field analysis of ground stone and limited surface collection. With assistance from the INAH Centro Regional in Chihuahua we also arranged to have large-scale aerial photographs taken of Cerro Juanaqueña and four other nearby cerros de trincheras, as well as a part of the floodplain near Cerro Juanaqueña. Analytical activities continued, and we are able to report two additional radiocarbon dates on materials excavated in 1997, as well as preliminary results of the geomorphological study, pollen analysis, and lithic analysis. In 1998 we expanded our project to include limited work at two other cerro de trincheras in the Rio Casas Grandes drainage, Cerro los Torres and Cerro Vidal (see Figure 2). Both of these sites were originally registered and mapped during Minnis and Whalen’s project in 1996. Cerro los Torres is located about 20km north of Nuevo Casas Grandes. The site consists of over 2 km of terrace walls and perhaps 20 rockrings built on an 85 m high isolated hill overlooking the floodplain. Although some pottery and a few arrow points have been found on Cerro los Torres, it also has dart points and other artifacts which are reminiscent of those at Cerro Juanaqueña. The terraces and stone circles are also similar to the features on Cerro Juanaqueña. For these reasons we suspect that the site was originally built and used during the Late Archaic period. This site and our test excavations there are described more fully in Appendix 2. Cerro Vidal is a third cerro de trincheras located adjacent to the Rio Piedras Verdes 6 kilometers south of Colonia Juarez in the municipio of Casas Grandes Viejo. This site is located on an 120 m high hill. It includes approximately 2.3 km of terrace wall and about 40 rock rings. No pottery has been found, and although there are arrow points on the site, its overall similarity to Cerro Juanaqueña in terms of artifacts and form of its features suggests that it also dates to Late Archaic times. Owing to newly acquired data, this last suggestion has been reconsidered. This site and our test excavations there are described in Appendix 3.