“…Caves and the natural water-filled sinkholes called cenotes were places where human sacrifices, often children, were made, where the Maya buried their dead, and where the living went to make offerings of various types to gain the favor of their ancestors and supernatural beings, such as earth and rain gods (Brady, 1989;Gibbs, 1998;Ishihara, 2008;Moyes et al, 2009;Prufer, 2002Prufer, , 2005Tozzer, 1941;Vogt and Stuart, 2005). Many objects have been used as offerings by past and present-day Maya, including animals, blood, ceramics, wood, candles, incense, maize, cacao, shells, crystals, pebbles, obsidian blades, and chipped-chert flakes and implements (e.g., Awe et al, 2005;Bassie-Sweet, 1991;Brady and Prufer, 1999;Halperin et al, 2003;Morehart, 2005;Moyes et al, 2009;Prufer, 2002Prufer, , 2005Prufer and Hurst, 2007;Prufer et al, 2003). Like their modern descendants, the ancient Maya associated chert with lightning (Freidel et al, 1993, p. 200), and given that many underworld rituals focused on rain, fertility, and sustenance, the deposition of chert debitage in caves and rockshelters may very likely have been related to this ideology.…”