Probabilities of designed locations of ceremonial foci: the Chaco Meridian, temple IV at Tikal, and a large-scale sacred Adena river landscape

ABSTRACT Considering that prehistoric cultures may have had the socio-religious need and technical ability to create accurate geometric patterns across a large landscape, limited ethnographic and archaeologic evidence are reviewed. Simple but accurate land surveying is discussed. Since any set of existing sites at larger scales coincidentally creates accurate three-point alignments and right-angles, the critical research problem attempts to distinguish designed from random geometry. Unpublished patterns involving great kivas in Chaco Canyon and Temple IV at Tikal are tested for probabilities of design. The more expansive third test considers the location of 26 prominent Adena mounds in relation to 32 river confluence points and four highest mountains in a geographic area some 900 × 1200 km, just slightly larger than a Chacoan world. In 14 test boxes modeling the locations of the 26 mounds, 1000 sets of random points replace equal numbers in each box. Each set is searched for numbers of three-point alignments and ninety-degree angles at or under 0.10º accuracy. Chaco and Tikal tests show a strong likelihood of design at these sites; in the Adena, data indicate a high probability that some number of existing patterns were intentionally surveyed.