Radon -activity, uranium content and activity ratios of uranium and thorium [Ac(238U)/Ac(232Th)] have been determined in different layers of stratigraphical quaternary travertine deposits in the Errachidia area (High-Atlas, Morocco), by using two solid state nuclear track detectors (SSNTD), of CR-39 and LR-115 type II. The mineralogy of samples has been determined by X-ray diffraction. Correlation between the stratigraphy, uranium content and radon -activity has been investigated. An uranium-aragonite association has been found.