Pore water chemical composition was analyzed in 19 piston cores from near Keathley Canyon lease block 195 in the Northern Gulf of Mexico to assess the reliability of seafloor sulfate gradients as indicators of subsurface gas hydrates. Steep sulfate gradients result from greater methane flux, which has been related to the abundance of subsurface hydrate in other gas hydrate provinces (Borowski et al., 1999). In the Northern Gulf of Mexico, however, salt tectonism and related faulting imparts spatial and temporal heterogeneity on fluid flux, fluid chemistry (e.g., salinities), and thermal gradients -- factors that, in turn, affect the distribution, concentration, and composition of gas hydrates.