Analytical results on palagonite samples and manganese crusts from the Mid-Atlantic Ridge

A suite of three palagonites from pillowed basalts collected from within the Mid-Atlantic Ridge rift valley between 25°N and 30°N wer analysed along with another suite of two hydrothermally altered basaltic breccias and four hydrothermal manganese crusts collected from the TAG hydrothermal field at 26°N on the Mid-Atlantic Ridge. These specimen were collected during Trans-Atlantic Geotraverse (TAG) NOAA cruises using the R/V Discoverer. Two more hydrogenous ferromanganese crusts wer also analysed. They were collected from the eastern extension of the Atlantis Fracture Zone aboard the R/V Kurchatov in 1975. Radiochemical neutron activation analysis has been used to determine Tl, Rb. Cs. Co and Cr. Iron, Mn, and Mg concentrations in the crystalline samples and Mn crusts have been determined by AAS. K was determined by flame photometry, and S in these samples (as well as five glasses) has been determined with a Leco Automatic Sulfur titrator.