A comparison of vitrinite reflectance measurements made on whole-rock and dispersed organic matter concentrate mounts

A comparison of mean-random vitrinite reflectance (R(v-r)) values calculated from measurements on polished whole-rock and on concentrates of dispersed organic matter (DOM) mounts of the same samples generally show little difference. Compared to measurements on DOM mounts, R(v-r) measurements by the same microscopist on corresponding whole-rock samples are up to a few tenths of a percent lower over the range of 0.6-3.2% R(v-r) and have a slightly higher standard deviation. Whole-rock mounts have an advantage over DOM mounts in the identification of first-cycle vitrinite and differentiation of solid bitumen from vitrinite.