Four silicate glasses were prepared by the fusion of about 1 kg powder each of a basalt, syenite, soil and andesite to provide reference materials of natural composition for microanalytical work. These glasses are referred to as ‘Chinese Geological Standard Glasses’ (CGSG) ‐1, ‐2, ‐4 and ‐5. Micro and bulk analyses indicated that the glasses are well homogenised with respect to major and trace elements. Some siderophile/chalcophile elements (e.g., Sn, Pt, Pb) may be heterogeneously distributed in CGSG‐5. This paper provides the first analytical data for the CGSG reference glasses using a variety of analytical techniques (wet chemistry, XRF, EPMA, ICP‐AES, ICP‐MS, LA‐ICP‐MS) performed in nine laboratories. Most data agree within uncertainty limits of the analytical techniques used. Discrepancies in the data for some siderophile/chalcophile elements exist, mainly because of possible heterogeneities of these elements in the glasses and/or analytical problems. From the analytical data, preliminary reference and information values for fifty‐five elements were calculated. The analytical uncertainties [2 relative standard error (RSE)] were estimated to be between about 1% and 20%.

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Argentian cryptomelane as a quite rare variety is determined during the investigation of Mn-Ag ore samples from Xiangguang deposit along the northern margin of North China craton. The mineral observed by a polarizing petrographic microscope involves concentric ring-band, pisolitic and veinlet structures and greyish white color. The scanning electron microscopy reveals a large number of elongated nanocrystals in the forms of nanofibers and nanorods in this densely natural argentian cryptomelane. The specifically chemical features in two samples of XG-C-1 and XG-C-2 of cryptomelane are: (1) The silver content ranges from about 0.22-3.15 wt%, which is much higher than that of other manganese oxides including ranciéite, chalcophanite and coronodite found in this deposit as well. Both of two argentian cryptomelane samples feature two main Raman scattering contributions at about 580 cm −1 and 630 cm −1 , belonging to the Mn-O lattice vibrations within the MnO 6 octahedral double chains, which can distinguish from other three manganese oxides. The Ag + prefers to locate in the tunnel sites substituting K + of cryptomelane due to its large radius and the same monovalent state with K + . Some chain-width disorders characterized by transmission electron microscopy are probably caused by these cation substitutions.

An experiment was designed and carried out to measure the XRF yield distribution over the area irradiated by the target's x‐rays in a polarized EDXRF spectrometer. A small solder disc, which was made of mainly lead and tin and with a diameter of about 3 mm, was scanned manually with equal displacements over the area. XRF spectra excited by radiation from three typical targets, namely, highly oriented pyrolytic graphite (HOPG), Mo and Al2O3, were collected. Intensities of Sn Kα and Lα and Pb Lα and Mα lines were obtained and used to describe the XRF yield distributions from different targets. The results showed that the total areas contributing to the XRF signal were over 2 cm2 for the above three targets. Also, Pb Mα and Sn Kα maps irradiated by HOPG and Al2O3, respectively, showed very high intensities in the central parts, while they were very low in the periphery. The sum of intensities from four spots in central area (corresponding to about 7 × 7 mm2) represents about 50% of overall integrated intensities of the 33 measured spots. Also, the sharpest areas of Pb Mα and Sn Kα were slightly shifted. Pb Lα maps obtained using the Mo target showed much larger distribution areas, with center being the most intense and becoming weaker gradually toward the outer parts. The relatively small irradiation areas of the polarized targets may require better sample homogeneity, and care should be taken when small pieces of samples are to be analyzed. Copyright © 2007 John Wiley & Sons, Ltd.

Co-rich seamount crusts have been shown to possess great potential for providing information on paleoceanographic and paleoclimatic changes. High resolution data are essential to decipher and correctly understand such high-density records. With the development of modern micro-probe techniques, detailed sampling of crusts can be performed and it is possible to retrieve detailed information about environmental changes recorded in the seamount crusts. We report here geochemical results of more than 40 elements (including all rare earth elements) of four Co-rich seamount crust samples, which were collected from seamounts in the central and western Pacific Ocean. These data were obtained with two micro-probe techniques: Electron Probe Micro Analyzer and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. The chronological framework of the seamount crust samples was determined using the cosmogenic 10 Be and the Co-chronometer. Records of elemental composition, P, and Al/(Fe + Mn) and Y/Ho ratios across the sections of the four samples are used to identify paleoceanographic and paleoclimatic events over the past ~30 Ma. These data show that: (1) Al/(Fe + Mn) in the western Pacific seamount crust is a useful proxy for the assessment of changes of source materials related to the variability of the Asian monsoon; (2) P and Y/Ho can be used as proxies to infer biogenic episodes. Finally we discuss the methodology related to dating and micro-probe analysis used in crust study.Co-rich seamount crust, micro-probe, chronology, geochemical record, paleo-oceanic environment During the last ten years' investigation on marine geology and mineral resources in deep oceans, marine ferro-manganese oxides, especially Co-rich seamount crusts, laminated mineral deposits, have been shown to have great potential for obtaining information on long-term paleoceanographic and paleoclimatic changes and have attracted the attention of the scientists around the world. The formation of Fe-Mn crust by deposition of ions or molecules is an extremely slow process at an average growth rate of only one atomic layer per year [1] . Therefore, Co-rich seamount crusts are virtually condensed stratigraphic sections in which several millimeters can represent one million years of oceanic history [2,3] .Great progress has been made in the study of the