climatic characteristic of this region is the high concentration of rain during the rainy season (93% of total volume). When evaporation is analyzed, the region presents an annual deficit of 176 mm. Despite these particular variations, the regional climate is classified as tropical, with a rainy summer and dry winter. During dry periods, the above ground water sources can become very scarce although underground drainages are capable of keeping the discharge in Velhas River. Chronology The chronology of the site is based on OSL and radiocarbon dating and it defines three distinct human occupation periods with the oldest one starting at 12.7-11.7 cal kyBP (all chronological ranges are based on a 95.4% interval). If we consider a 95.4% confidence interval Lapa do Santo's Period 1 (LSP-1) starts at 12.7 cal kyBP and ends at 7.9 cal kyBP, Lapa do Santo's Period 2 (LSP-2) starts at 5.4 cal kyBP and ends at 3.9 cal kyBP; Lapa do Santo's Period 3 (LSP-3) starts at 2.1 cal kyBP and ends at 0.0 cal kyBP. When the three periods are considered there is a very good agreement between vertical position (i.e., z-value) and dated charcoals showing the stratigraphic integrity of the deposits. At Lapa do Santo a total of 63 charcoal samples were selected for radiocarbon dating. Of those 53 were sent to the Beta Analytic AMS system in Miami and 10 to the Oxford Radiocarbon Accelerator Unit. In total 21 sediment samples were collected for luminescence dating, including two outside the shelter in the lake basin. The samples were mainly collected from test unit Q48 in the northern part of the shelter, from a T-shaped trench extending from the northern to southern part of the shelter, and from test units F13 and M6 in the main area of excavation. Analysis were conducted by Prof. James K. Feathers of the University of Washington. According to the OSL samples the earliest human occupation appears to date from about 9.0 to 12.0 kyBP, consistent with other paleoindian occupations in Lagoa Santa. In the unit F13 dates are at least two thousand years older than the dates obtained from radiocarbon. Formation processes and stratigraphy Formation process analysis characterizes Lapa do Santo's deposits as mainly anthropogenic and composed by repeated combustion activities, indicating an intense occupation of the same locality over time. The macro stratigraphy of Lapa do Santo shows an intercalation of layers with diffuse to sharp