Methods of and systems for determining depths of provenance of drill cuttings contained in a drilling fluid received from a wellbore, the drilling fluid containing drill cuttings of different sizes that arrive at surface at different recorded times, the drill cuttings originating from different formation layers at different depth along the wellbore. Such methods may include repetitively extracting samples of drill cuttings smaller than a predetermined threshold from the drilling fluid as necessary to provide samples of drill cuttings that arrive at surface at different recorded times; characterizing drill cuttings in the samples, comprising characterizing one or more formation attributes associated with the drill cuttings; and for each formation attribute estimating a distribution of formation attribute characterization versus depth of provenance, comprising defining a hydrodynamic transport of the characterized drill cuttings within the drilling fluid, including an effect of diffusion and dispersion on the hydrodynamic transport.