Characterization of Biogenic Manganese Nodule by XDR and XRF Analysis

• Published in: Advances in X-Ray Chemical Analysis, Japan Vol. 48; pp. 169 - 174
• Main Author: SEYAMA, Haruhiko
• Format: Journal Article
• Language: Japanese
• Published: The Discussion Group of X-Ray Analysis, The Japan Society for Analytical Chemistry 31.03.2017; 公益社団法人 日本分析化学会 X線分析研究懇談会
• Subjects: Biogenic manganese oxide; Manganese nodule; Oppu mine; X-ray diffraction; X-ray fluorescence; マンガンノジュール; 尾太鉱山; 微生物起源マンガン酸化物; 粉末X線回折; 蛍光X線分析
• ISSN: 0911-7806; 2758-3651
• DOI: 10.57415/xshinpo.48.0_169

Biogenic manganese nodules collected from the ground water in the Oppu mine, Aomori, Japan were characterized by X-ray powder diffraction (XRD) and X-ray fluorescence spectroscopy (XRF). The XRD pattern of the wet original sample showed characteristic diffraction lines of a layered manganese oxide (phyllomanganate) with a 1 nm d-spacing. After air-drying, it was suggested by XRD that the manganese nodule was transformed into a phyllomanganate with a 0.7 nm d-spacing due to the loss of interlayer water. X-Ray fluorescence spectra and elemental mapping of the cross section of manganese nodule were taken by a scanning XRF microscope. Zn, Ca, etc., in addition to Mn, were detected by XRF analysis of the manganese nodule. The manganese nodule had a layered ring structure and Zn-enriched layers were found by XRF elemental mapping of the cross section. In the central part of manganese nodule, there were fine mineral particles containing Si, Fe, Pb, etc. It is suggested from this study that the manganese nodule consisting of phyllomanganate grew concentrically around the mineral particles by the biomineralization of microorganisms.