TUFA-COATED SERPULID MOUNDS IN THE DOMINICAN REPUBLIC: A UNIQUE SUBSTRATE FOR TAINO INDIAN PETROGLYPHS

Late mid-Holocene tufa-coated serpulid mounds in the southwestern Dominican Republic provide an unusual substrate for Taino Indian petroglyphs. The petroglyphs are representations of Taino deities and human faces, some with artistic characteristics and elaborate facial expression. Carved faces have a diameter of approximately 18 to 51cm and carving depths of 2 to 11cm. Carved surfaces are reddish brown in color, similar to the surrounding tufa substrate. Modern graffiti made in this substrate reveal the light gray to brown color of freshly exposed tufa, permitting a distinction between authentic Taino carvings and contemporary imitations.

The tufa-coated serpulid mounds cap a mid-Holocene coral reef sequence along the paleo-shoreline of Lago Enriquillo. This hypersaline lake formed by the closure of a Caribbean seaway about 4000 ybp and its evaporation to about 40m below present sea level. The serpulid mounds are up to 2 m tall and they formed under variable environmental conditions during and subsequent to seaway closure. With decreasing lake levels, serpulid mounds provided substrates for microbially induced tufa precipitation as evidenced by well-preserved cyanobacterial filaments in the tufa coatings. Evaporation of Lago Enriquillo ended tufa precipitation and exposed the mounds.

In the 16th century Taino Indians carved petroglyphs in the porous tufa substrates using locally available tool materials. Tufa thickness (5 to 20cm) controlled carving depth. The carvings provide unique evidence for inhabitation of the area by Taino Indians. Sites with the greatest concentration of petroglyphs may indicate the location of villages between 1519 and 1533 when Tainos, under the leadership of Chief Enriquillo, fled to the Enriquillo Valley during a revolt against Spanish rule. Despite desecration by modern graffiti, preservation of the tufa substrates and these unique and well-preserved petroglyphs is enhanced by the semi-arid climate in the area today.