The development of a site chronology is partially based upon a 3 m deep test trench on the interior portion of the central mound (Figure 7). Discrete cultural strata were isolated. They included reworked cultural fills, features (hearths, firing sites, burnt floors), remnants of standing water and silty sands, and mudbrick courses or walls. The lowermost occupation horizon within the profile (layer XIII) produced a calibrated radiocarbon date of 2870 B.C. (and see Table 2 of radiocarbon dates), which falls between the Ravi (Hakra) and Early Harappan. A small number of sherds bear a textural surface that is similar to Hakra types and lends support to the possibility that the site was occupied during the earliest levels at Harappa. Additional study of materials housed at Harappa could resolve this issue. Two meters above, a fill deposit yielded a calibrated date of 2445B.C., and an overlying burnt floor provided a calibrated date of 2280 B.C. These dates suggest that the transition from the Early to Mature Harappan is registered within the central sedimentary sequence at the site.