Abstract : <p>Transient evolution and adjustment to changing tectonic and climatic boundary conditions is an essential attribute of landscapes. We present a new approach to detect and quantify transience in slow erosion landscapes over 100 ka timescales. We compare curvature and cosmogenic nuclides measurements (<sup>10</sup>Be and <sup>26</sup>Al) at hilltop sites with predictions of hillslope diffusion theory, in the slowly evolving quartzitic Serra do Cipó range in SE Brazil, and we observe a distinctive signature of an acceleration of denudation. The timing of this increase cannot be unequivocally associated with a single climatic event but is consistent with climatically-modulated important fluctuations in precipitation and erosion in this area during Middle and Late Pleistocene.</p>