Complexities of collapse: the evidence of Maya obsidian as revealed by social network graphical analysis

The authors use a social network analysis to map the changing patterns of obsidian supply among the Maya during the period of Classic to Postclassic transition. The quantity of obsidian received from different sources was calculated for 121 sites and the network analysis showed how the relative abundance of material from different sources shifted over time. A shift from inland to coastal supply routes appears to have contributed to the collapse of inland Maya urban centres. The methods employed clearly have a high potential to reveal changing economic networks in cases of major societal transitions elsewhere in the world.