A method for characterizing a wellbore depth interval from rock fragments, the method comprising: obtaining the rock fragments for a given depth interval from a drilling fluid expelled during drilling of the wellbore, splitting the rock fragments into a bulk rock fragment sample and a plurality of individual rock fragment samples, and analyzing the bulk rock fragment sample and the plurality of individual rock fragment samples to obtain measurements of the bulk rock fragment sample and of the plurality of individual rock fragment samples, wherein the method is characterized by comprising: converting, by a calibration technique, the measurements of the bulk rock fragment sample and of the plurality of individual rock fragment samples to a concentration percent that comprises a volume percent or a weight percent of the bulk and individual rock fragment samples, wherein the weight percent comprises an elemental weight percent, a mineralogical weight percent or total organic carbon; computing a normalized deviation for each of the plurality of individual rock fragment samples relative to the bulk rock fragment sample, said normalized deviation being derived from the concentration percent of the bulk and individual rock fragment samples; wherein the measurements of the bulk rock fragment sample are considered representative of the rock composition and the plurality of individual rock fragment samples is compared to the bulk rock fragment sample, ranking the plurality of individual rock fragment samples based on the corresponding normalized deviation; selecting, as representative of the rock present in the wellbore depth interval, one or more individual rock fragment samples of the plurality of individual rock fragment samples based on the corresponding ranking; characterizing the rock properties of the wellbore depth interval from which the bulk and individual rock fragment samples originated using measured properties of at least some of the selected one or more individual rock fragment samples; and presenting to a user the characterized wellbore depth interval. obtaining the rock fragments for a given depth interval from a drilling fluid expelled during drilling of the wellbore, splitting the rock fragments into a bulk rock fragment sample and a plurality of individual rock fragment samples, and analyzing the bulk rock fragment sample and the plurality of individual rock fragment samples to obtain measurements of the bulk rock fragment sample and of the plurality of individual rock fragment samples, wherein the method is characterized by comprising: converting, by a calibration technique, the measurements of the bulk rock fragment sample and of the plurality of individual rock fragment samples to a concentration percent that comprises a volume percent or a weight percent of the bulk and individual rock fragment samples, wherein the weight percent comprises an elemental weight percent, a mineralogical weight percent or total organic carbon; computing a normalized deviation for each of the plurality of individual rock fragment samples relative to the bulk rock fragment sample, said normalized deviation being derived from the concentration percent of the bulk and individual rock fragment samples; wherein the measurements of the bulk rock fragment sample are considered representative of the rock composition and the plurality of individual rock fragment samples is compared to the bulk rock fragment sample, ranking the plurality of individual rock fragment samples based on the corresponding normalized deviation; selecting, as representative of the rock present in the wellbore depth interval, one or more individual rock fragment samples of the plurality of individual rock fragment samples based on the corresponding ranking; characterizing the rock properties of the wellbore depth interval from which the bulk and individual rock fragment samples originated using measured properties of at least some of the selected one or more individual rock fragment samples; and presenting to a user the characterized wellbore depth interval. converting, by a calibration technique, the measurements of the bulk rock fragment sample and of the plurality of individual rock fragment samples to a concentration percent that comprises a volume percent or a weight percent of the bulk and individual rock fragment samples, wherein the weight percent comprises an elemental weight percent, a mineralogical weight percent or total organic carbon; computing a normalized deviation for each of the plurality of individual rock fragment samples relative to the bulk rock fragment sample, said normalized deviation being derived from the concentration percent of the bulk and individual rock fragment samples; wherein the measurements of the bulk rock fragment sample are considered representative of the rock composition and the plurality of individual rock fragment samples is compared to the bulk rock fragment sample, ranking the plurality of individual rock fragment samples based on the corresponding normalized deviation; selecting, as representative of the rock present in the wellbore depth interval, one or more individual rock fragment samples of the plurality of individual rock fragment samples based on the corresponding ranking; characterizing the rock properties of the wellbore depth interval from which the bulk and individual rock fragment samples originated using measured properties of at least some of the selected one or more individual rock fragment samples; and presenting to a user the characterized wellbore depth interval.