Microelements in nontronites from bottom sediments of the Sea of Okhotsk

X-ray powder diffraction, infrared spectroscopy, scanning electron microscopy, and synchrotron radiation X-ray fluorescence analysis (SRXFA) are applied to determine the macro- and microelement composition and crystal structure of nontronites (high-iron minerals of the smectite group), found in the Sea of Okhotsk for the first time. It is shown that the samples of postvolcanic sediments with an Fe/(Fe+Al+Mg) ratio ranging from 0.79 to 0.84 are more highly charged, nonswelling, poorly crystallized (b similar to 9.14 ), and contain more structural defects and microelements, such as Cu, Ni, Pb, Rb, Sb, Sn, and Y, as compared to samples from the central part of the Sea of Okhotsk. For the latter with a Fe/(Fe+Al+Mg) ratio from 0.87 to 0.9, parameter b is similar to 9.11 . Minor differences in the concentrations of K, Ca, Mn, and Ti elements have been detected. The SRXFA data in combination with the used physicochemical methods give an explanation for the differences in the properties of the studied samples.