Human–environment interactions at Ta'ab Nuk Na, a submerged Maya salt works site in Belize

Sea-level rise and settlement are investigated at Ta'ab Nuk Na, an ancient Maya salt works in Belize, by examining samples from wooden posts and marine sediment. The samples included Post 145 of Building B and the Nunavut beam, along with marine sediment columns cut from beside both wooden posts. The sediment columns were sampled at 2 cm intervals. Loss-on ignition confirmed the presence of organic material. Identifying the organic content involved removing nonorganic material from the sediment and sorting the organic material under magnification. This procedure established that most of the organic material was red mangrove (Rhizophora mangle). Red mangroves tolerate salt water, but under conditions of sea-level rise, the plants grow vertically to keep their leaves above water. Sediment, leaves, and detritus trapped in the prop roots form mangrove peat, which serves as a proxy for sea-level rise. AMS dating of fine red mangrove roots determined that the local sea levels rose at Ta'ab Nuk Na throughout the Late Classic period and continued into the Postclassic period. Radiocarbon dates obtained from the wood-post samples yielded Late Classic–period dates. Comparing the radiocarbon dates from the wooden posts and the sediment core samples determined that the site was abandoned before the rising seas flooded the area. Evidently, sea-level rise did not play a role in site abandonment.