Tectonic uplift is the portion of the total geologic uplift of the mean Earth surface that is not attributable to an isostatic response to unloading. Isostatic response is important, however, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal thickening (such as mountain building events), changes in the density distribution of the crust and underlying mantle, and flexural support due to the bending of rigid lithosphere. It is also good to take into consideration the effects of denudation (processes that wear away the earth’s surface). Within the scope of this topic, uplift relates to denudation in that denudation brings buried rocks closer to the surface. This process can redistribute large loads from an elevated region to a topographically lower area as well – thus promoting isostatic response in the region of denudation (which can cause local bedrock uplift). The timing, magnitude, and rate of denudation can be estimated using pressure-temperature studies.