GEOLOGICAL ORIGIN AND CULTURAL SIGNIFICANCE OF SASCAB ON THE YUCATÁN PENINSULA IN MEXICO

Sascab (saskab or sahkab) is a friable carbonate material that has been used extensively since antiquity for construction and paving throughout Mesoamerica. The term sascab refers to “rotten or decomposed limestone” that looks like “white earth” (“tierra blanca”), and is quarried from shallow pits called sascaberas. The distribution and great abundance of sascaberas indicates that sascab was a very important natural mineral resource for the inhabitants of the Yucatán Peninsula in Mexico.

Yucatán is a relatively flat, low-elevation terrain made of Cenozoic carbonates deposited on a broad, gently sloping ramp. Sascab is the main component of the carbonate-rich soil (caliche or calcrete) profile formed by extensive weathering during subaerial exposure of predominantly shallow subtidal limestone. The profile can be several meters thick and it gradually transitions downward and laterally into less altered limestone bedrock. The top of the profile is marked by a well lithified caliche crust (hardpan), which makes the roof of sascaberas.

Weathered limestone underneath this indurated surficial crust consists of crumbly white powdery/chalky to granular sascab that was relatively easy to excavate by the ancient Maya using simple stone tools. The Maya used this raw powder-gravel mixture extensively for making traditional “white roads” (sacbeo'ob). They also ground this material using stone grinding tools for pottery applications. Together with larger carbonate rock pieces incorporated within sascab, it was used as a construction fill for interiors of walls and solid structures of buildings. Fist-size rock fragments from sascab were also burned for lime production.

Of special significance were rounded to subrounded cobble-size pieces of well indurated (piedra dura), fine-grained, muddy limestone found in sascab. These pseudoclasts are relics of host rock formed in situ by weathering and pedogenic modification of limestone. They were easily shaped into a variety of grinding/pulverizing (grains, plaster, pigment), hammering/pounding (bark for paper), and smoothing/flattening (paper, plaster) tools. These observations support the conclusions that limestone and its weathering products, as the only locally abundant stone resources, were utilized by the Maya to maximum extent for a variety of purposes.