Probing the foundation of the Mid‐Atlantic Ridge

Leg 153 of the Ocean Drilling Program drilled five sites on the western wall of the Mid‐Atlantic Ridge (MAR) between 23°20′N and 23°30′N, at distances of 5–35 km south of the Kane Transform (Figure 1). This area—referred to as the MARK—is one of the most extensively studied portions of the mid‐ocean‐ridge system. Core recovered on Leg 153 represents the most continuous sampling to date through a section of sub‐oceanic mantle, as well as temporally and spatially diverse sections of the lower crustal plutonic rocks. Results from postcruise research programs will specifically address models of magma evolution, tectonic activity, and hydrothermal alteration in slow‐spreading oceanic crust.