Discussion of a paper by David L. Kendall (GeoScience Abstracts 2-3090). Four points are raised that do not support a syngenetic origin for Zn ores of the E. Tennessee district: 1) Age of the sand-filled vugs is critical. It seems no easier to make them primary sedimentary structures than later ones. More data are needed on the relative attitude of the sand laminations and the country rock bedding. 2) It is doubtful that extent and importance of reefs is sufficient to have caused Zn to precipitate from sea water. 3) Any theory of ore deposition should explain both the Tennessee ores and the fluorite and barite deposits at Sweetwater. Can algae precipitate barite and fluorite? 4) The sedimentary theory does not explain the fact that many E. Tennessee ore bodies are associated with arch and dome structures.