Caryn seamount (36°42′N, 68°02′W) was discovered in 1948 during Caryn cruise 1. Since that time many vessels have passed over this feature. It is an isolated seamount, lying some 350 km southwest of the nearest seamount of the New England‐Bermuda arc described by Northrup et al. [1962], and it rises above the Sohm abyssal plain from a depth of 5097 m to a depth of 2965 m at its peak; the base diameter is 12 km [Heezen et al., 1959]. A large positive magnetic anomaly associated with Caryn seamount [Miller and Ewing, 1956] suggests that it is of volcanic origin. Upper Cretaceous fossils showing recrystallization attributed to volcanic solutions and younger (not recrystallized) fossils of various Tertiary ages obtained in cores on the seamount led Miller and Ewing to suggest a date of Late Cretaceous for the volcanic activity.