Microprobe analysis of a manganese nodule sample from the MN7601-PLEIADES campaign (R/V Melville)

The authors have selected for analysis a manganese nodule from Station 20 of the PLEIADES Mn7601 campaign. This "apple" shaped nodule (6.5x3.0 cm) was laying on a bed of siliceous ooze (see illustrations). Electron microprobe measurements were made on the same section as that used in the alpha-track studies. Prior to the microprobe analyses, however, the nodule slab was highly polished to reduce surface relief A MAC electron microprobe was employed and the electron beam was focused to a dmmeter of about 2 micrometers using 15 kV and 300 mA.