SIGNIFICANCE OF LIMESTONE AS THE GEOLOGIC SUBSTRATE FOR MAYA CIVILIZATION IN THE NORTHERN YUCATÁN PENINSULA: A CASE STUDY FROM MAYAPÁN, MEXICO

Limestone and the products of its subaerial weathering, as the only locally abundant stone resources, were extensively utilized by inhabitants of the last Maya capital Mayapán (c. 1100 to 1450 AD) in NW Yucatán, Mexico. Exposed in this relatively flat karst lowland are mainly shallow subtidal Cenozoic limestones deposited on a broad, ramp-shaped carbonate platform on top of the deeply-buried end-Cretaceous Chicxulub impact crater, whose surface expression is a ring of sinkholes or cenotes.

Coarse coquina limestone is the most abundant stone in the Mayapán area and was used extensively for the making of lime, building blocks, some sculptures, grinding and abrading tools, and disc-shaped beehive lids. Common also is calcarenite limestone, which was relatively easy to carve into sculptures using chert tools due to its finer-grained, uniform texture. Especially suitable for stone tools, but not very abundant, is piedra dura or well indurated muddy limestone found as subrounded pseudoclasts in extensively weathered limestone (sascab), excavated from shallow pits (sascaberas). These fragments were easily shaped into a variety of hammering/pounding, grinding/pulverizing, and smoothing/flattening tools, while sascab was used extensively as construction fill for buildings, making traditional “white roads” (sacbeo'ob), and ground for pottery applications.

Monumental and residential architecture regularly utilized the antecedent karst topography of small hills (altillos). Limestone blocks for outer walls were flattened using chert tools after extraction from shallow local quarries. Calcrete or caliche crust also provided naturally flat rock surfaces. Interior walls and solid structures were filled with locally available limestone and paleosol fragments. The general lack of large quarries suggests that most limestone for architecture and lime production was sourced directly from the exposed karstified surface. Slash and burn agriculture that the Maya practiced helped clear the surface and enhance access to weathered limestone exposures. Karst processes of limestone dissolution also resulted in the formation of cenotes as a crucial fresh-water source. These examples demonstrate the great significance of the limestone substrate for Maya civilization in the northern Yucatán Peninsula of Mexico.