Abstract
Characterizing the in-place conditions of rock masses commonly depends upon continuous diamond-core drilling for site investigation or resource characterization. However, because of incomplete or inconsistent core descriptions, potentially valuable information may be lost or unavailable for other users. This situation suggested the potential value of photographic core-logging manuals and descriptive codes to facilitate consistency in core description and ease in the transfer and computerization of these descriptions. To that end, this article describes the development of such manuals and codes using the U.S. eastern gas and oil shales as examples. Although the described manual was developed specifically for these rocks because of their energy-related significance, the concept and coding scheme are readily applicable to core description for all types of engineering and geological purposes.