THE APPEARANCE FEATURES AND ENVIRONMENTAL INDICATION OF SURFACE SEDIMENTS IN CHUKCHI SEA AND CANADA BASIN

The apparent features of surface sediments collected during Chinese First and Second Arctic Research Expedition were observed. Based on the recognition of color and odor of the sediments, distribution of gravels or ice-rafted debris and molluscan remains in the surface sediments, we discuss the relation a-mong the apparent features of surface sediments and the content of organic matters, oxidation-reduction status as well as the distribution range of benthos, ice-rafted detritus and the relation with ocean current. We find that the north boundary of mollusks is located at 73.5°N, which is 2° lower than that of zooplank-tons. The north boundary of ice-rafted detritus which is also the north boundary of melting water and equals to the south boundary of permanent ice region, appears near 77°24'N. According to analysis of ap-parent features of sediments, combining with current characteristics in study area, we conclude that cur-rent plays an important role in distribution of sediments, especially for that within the southwest region and east region.