Minor Elements in Shallow-Water Deposits from Nanao Bay, Japan

Abstract

The minor elements Ni, Co, Cu, Zn, Pb, Cd, Cr, V, Mo, Zr and Ga were studied in 21 samples of shallow-water deposits from West, South and North Bays of Nanao. Ni (av. 14±5ppm), Co (av. 6±2ppm), Zn (av. 51±7ppm), V (av. 39± 6 ppm) and Mo (av. 0.5±0.3 ppm) were not so much concentrated in these deposits as in pelagic deposits, but only Ga (av. 12±3ppm) shows concentration similar to that in pelagic sediment. It is characteristic of these deposits that Pb (av. 55±6ppm) and Zr (av. 101±46 ppm) are notably abundant in them, compared with those of shallow-water deposits from all the coasts of Honshu, Japan, Korean coast and Gulf of Paria. The constancy of Co/Ni ratios was found in these deposits and red clays despite large difference in abundance of these elements in them. There are positive correlations between the contents of Ni, Zn and Ga and content of Al, and also between the contents of V and S.