Nuclear logging and mineral inversion in sedimentary sequences

The inversion of nuclear-derived chemistry into quantitative mineralogy, is considered. The roles of mineral choice and individual mineral composition are shown to be important in estimating an accurate model mineralogy. Compositional colinearity in which three or more of the phases sought lie on or close to the came compositional plane can produce unstable mathematical solutions. The absence of water and carbon dioxide data and the inability to measure Na and Mg individually contribute to the difficulties of the inversion process. Despite these concerns, a geologically meaningful mineralogy may be produced, though adequate validation of a particular solution still remains to be done.<>