宇和海表層堆積物の地球化学的特徴 Geochemical properties of surface sediments in Uwakai Sea
Chemical compositions of cored sea floor sediments from six stations (Yawatahama, Mikame, Hoketsu, Uwajima, Shitaba and Kitanada Bays) in Uwakai Sea along the western part of the Shikoku Island were analysed by instrumental neutron activation analyses, in order to evaluate influences of inflow materials from geological hinterland and human pollution. Scandium, chromium, iron and cobalt contents in the sediments from the Yawatahama and Mikame Bays, which locate to the northern part of the Uwakai Sea, are obviously high compared with that from other stations. This is strongly depended on the materials from geological hinterland. Mafic rocks including higher contents of such elements belong to the Sambagawa and Mikabu belts distributed in the area. By weathering of the rocks, the constituting particles directly deposit to the sea floor in the bay areas. On the other hand, zinc content of the sediments from the Yawatahama and Uwajima Bays is two times as large as that of the normal sediments. This may be caused by human pollution, because the twobays face to urban areas in the Uwakai Sea region. However, further examination is necessary to that the possibility of human influences, based on the genesis of sulfide in diatom and relationship between zinc and total organic carbon contents.
- 愛媛大学教育学部紀要. 第III部, 自然科学
愛媛大学教育学部紀要. 第III部, 自然科学 23(1), 13-24, 2002-09-20