Profile: Andrew M. (Andy) Munro is a Ph.D candidate at James Cook University Centre for Astronomy, studying under the supervision of Professors J. McKim Malville and Wayne Orchiston. Andy’s work includes archaeoastronomical field work in and around Chaco Canyon in the 2008 and 2009 field seasons, under National Park Service and Bureau of Land Management research permits. During his research, Andy identified workable horizon calendars at or near many Late Bonito Phase Great Houses, including Casa Chiquita, Headquarters Site A, and the outlier, Bis sa ani. Andy holds an M. Sc. in Astronomy from Swinburne University, and a B.S. (hon) in Political Science from Charter Oak College.
Presentation: “Solar Horizon Calendars of Chaco Canyon”
Abstract: The Great Houses of Chaco Canyon are interpreted by many Archaeologists as monumental architecture built by ancestral Pueblo peoples during the 11th and early 12th centuries A.D.. From the 1970′s to the 1990′s, many researchers identified workable horizon calendars associated with Chacoan cultural sites. The use of solar horizon calendars by modern Pueblo people for both religious and agricultural timekeeping is well documented.
My recent field work at Chaco has expanded the inventory of proposed calendrical stations significantly. Some of these, including 29SJ 931 near Wijiji Great House, and 29SJ 1655, also include rock art evidence associated with Dine (Navajo) culture, indicative of dual culture site use. My associates and I have also reviewed the full set of calendrical stations at Chaco that have been proposed to date. We have found that a majority of Great Houses constructed at Chaco during the late Bonito period (A.D. 1100 to 1140) are situated at or near workable observation points for solstice sunrise or sunset horizon markers. This provacative pattern of solstice calendrical associations is inconsistent with documented modern Pueblo practices. We interpret these associations as evidence that late Bonito leaders at Chaco were actively seeking to bolster a faltering system through demonstrations of their astronomical predictive skills, and the association of Great Houses with visual solstice events.