TUFA RECORDS OF HOLOCENE CLIMATE CHANGE IN HIGHLAND SOUTHERN YEMEN
In our study area, increased precipitation contributed to enhanced meteoric recharge of shallow aquifers discharging as springs, which served as point-sources for tufa formation. More active spring discharge led to the formation of expansive marsh and wetland environments, which are indicated by organic-rich lacustrine sediments grading from the tufa mounds to the wadi center. Fossil aquatic gastropods and plant impressions are abundant in the tufa sediments, providing additional evidence for the extensive riparian environment adjacent to the spring sources.
Radiocarbon age estimates determined on charcoal recovered from sand lenses within the tufa deposits are correlated with periods of more extensive human occupation in the region, as documented by the RASA (Roots of Agriculture in Southern Arabia) team. Evidence suggests that early farmers may have been exploiting water resources discharging from these fossil springs during the mid-Holocene humid phase. Subsequent aridification has led to abandonment of agricultural subsistence and return to pastoralism in much of the region.