DID ROCK COLORS PLAY A ROLE IN SELECTING COPáN'S LOCATION?

In contrast to the classical Mayan ceremonial centers constructed of Yucatan’s limestone, Copán, in western Honduras, and its satellite sites are constructed from ash flow tuffs and clastic sedimentary rocks derived from these tuffs. East of the acropolis, hydrothermally altered, green-tinted Miocene tuff overlies red beds (Cretaceous?). Gail Mahood reported that the light green tuff contains zeolites but that the color is due to trace quantities of montmorillonite. As this tuff weathers, it appears that the green clay content increases. A thin layer of green clay, slippery when wet, north of Copán is the same color as the interior of friable, highly weathered, tuff boulders in the nearby river. Some archaeologists speculate that Copán was founded to control the jade mined from the Motagua fault zone a short distance to the north. Was the presence of green rocks, in close association with red rocks, influence the Mayas’ decision to build Copán in this location? An abandoned quarry overlook the ceremonial center is similar to an active quarry several kilometers to the south, where men insert branches into joints, breaking off blocks the size of a refrigerator. They use a heavy hammer to split large blocks into rectangular prisms. Both large blocks and stones that have been worked, probably using similar tools, still lie under the jointed face of the abandoned Mayan quarry. Art historians striving to preserve deteriorating hieroglyphic blocks may have damaged the stone by introducing sodium ions while eradicating lichens and microbes with a sodium hypochlorite solution. An organized study of naturally weathered rocks might contribute information to the preservation effort.