Soil constraints on Northwest Yucatán, Mexico: Pedoarchaeology and Maya subsistence at Chunchucmil

Ancient Maya Commerce : Multidisciplinary Research at Chunchucmil

“…The coastal beach ridges of northern Campeche and western Yucatán, also called xeric beach ridges, are relatively young in geologic time, arriving at their general current configuration in the late Holocene, during the last 5,000 years (A. P. Andrews 1983:22;Eaton 1978:11;Beach 1998a). These active and slowly shifting beach ridges border and protect the broad cienega/estuarine zone described below.…”

“…These limestone flats are relatively impermeable (unlike the broken and highly porous landscape covering most of Yucatán) due to seasonal redeposition of dissolved calcite, causing surface cementation. This cementation exacerbates localized flooding during the rainy season because it blocks infiltration (Perry et al 1989;Beach 1998a;Pope et al 2001). Farther north within the CER (along a vector north from Rancho San Simon; see figures 1.2 and 8.1), the surface of the seasonally inundated savannas is more uneven, with slowly dissolving rounded cobbles of limestone covering the majority of the landscape.…”

“…The tzekeles west of Chunchucmil are fossilized beach ridges that parallel the modern coastline of the Yucatán Peninsula (Beach 1998a). We have not encountered any study that estimates the exact age of each fossilized beach ridge, but considering the ages of the modern beach ridges along the coast (over the last 5,000 years), along with the highly fossilized nature of the tzekeles' shelly conglomerate of biotic limestone, and the relatively large distance between the tzekeles and the coast (10-18 km), it is certain that they formed long before the arrival of humans in this area.…”

“…Yet, after centuries of working the soils around Chunchucmil, the local Maya have learned that these kancab flats support dense grasses that choke out most native crops, and these flats tend to puddle quickly after a heavy rain due to subsurface cementation. Therefore, farmers today avoid kancab flats in favor of the higher rocky hillocks of the tzekeles (and of course the ancient mounds themselves, which contain organic matter and deep clay pockets) (Beach 1998a).…”

“…Even where there is a soil cover, its thickness is often a few centimeters (Sweetwood 2008:4). According to local Maya farmers, the best soils (box lu'um) are located upon the archaeological mounds themselves and likely developed over the last 1,000 years since Chunchucmil's collapse and abandonment (Beach 1998a). Clearly these relatively young anthropogenic soils would not have been available to the ancient inhabitants of Chunchucmil.…”