Search

In 1990, the Institute of Geophysical and Geochemical Exploration prepared a series of certified reference materials of synthetic silicates and limestones. The silicate series (GSES I*) is composed of 11 samples with 28 ingredient elements and the limestone series (GSES II*) is composed of 9 samples with 29 ingredient elements. The standard series were prepared in ascending element concentration order of 1, 2 and 5. The synthetic standards were analyzed by a large number of laboratories with various reliable methods and then certified values were derived.

The Okinawa Trough is located between the shelf-sea area of the East China Sea and the deep-sea area of western Pacific Ocean. More than 60 chemical elements in the sediments from the shelf area of the East China Sea, the Okinawa Trough and western Pacific Ocean were determined by advanced techniques including neutron activation analysis, X-ray fluorescence spectrometry, atomic fluorescence spectrometry and atomic absorption spectrometry. Quantitative comparisons of the element abundances of the sediments were made in terms of the enrichment coefficients (K) of the elements.K > 1.5 indicates enrichment (K = 1.5–2, weak enrichment; K = 2–4, strong enrichment) andK > 4, anomalous enrichment. The results show that the Okinawa Trough sediments are characterized by Hg anomaly and the enrichment of such elements as Au, Ag, Se, Te, Sb, Cd, Mn, Mo, etc. Detailed studies show that the excess Hg comes from hydrothermal solutions rather than from the continent, sea water, marine organisms, cosmic dust or volcanic rocks. Attributed to modern hydrothermal activities on the sea floor, Hg anomaly can be used as a geochemical indicator of modern seafloor hydrothermal activity.

Usable values, derived principally from data by Chinese analysts, are presented for four new stream sediments (GSD 9-12) that supplement the original eight stream sediments (GSD 1-8), for eight soil samples (GSS 1-8), and for six rock samples (GSR 1-6). The rock suite consists of a granite (GSR-1), an andesite (GSR-2), a basalt (GSR-3), a sandstone (GSR-4), a shale (GSR-5), and a carbonate rock (GSR-6). The amounts of sample obtained, their locations, and brief descriptions are given. The samples are available to analysts who might wish to contribute data that may improve the estimates given in tables.