Abstract: An apparatus and method for a wellsite &ggr;-ray analysis of core samples is implemented. A wheeled carriage supporting a &ggr;-ray detector stably straddles a core sample, which may be encased in a core barrel. A bracket attached to the carriage may hold a radionuclide source of &ggr; radiation positioned distally from the detector, thereby forming a space therebetween for passage of the core. The density of the core may be determined by counting the &ggr; flux attenuated by the core; by traversing the carriage along a length of the core, the density may be determined as a function of position, and disrupted core or partial recovery detected thereby. Additionally, the natural &ggr; emission of the core may be observed by traversing the apparatus along the core without the radionuclide source.