(Table 1) Oxygen and hydrogen isotope ratios of hydrothermal altered dolerites from ODP Holes 137-504B and 140-504B

Dolerite samples, recovered in the dike complex between 1589 and 1991 meters below seafloor in Hole 504B during Legs 137/140, have been altered by hydrothermal fluids as shown by the intense replacement of igneous minerals by secondary amphiboles, chlorites, albite, and anorthite. These rocks display a negative correlation between alteration extent and density. This is interpreted in terms of the development of secondary light minerals and an increase in porosity. […]