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Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relationship between the Forbush decrease and the cosmic noise absorption during the polar night is analysed based on the data recorded by a Riometer at Antarctic Zhongshan Station (69° 22'24"S, 76°22'40"E). The relation of between the cosmic ray Forbush decrease and the cosmic noise absorption is well interpreted by means of the ionizaiotn theory.
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Rb-Sr isotopic isochron dating of the volcanic rock samples from the Upper Cretaceous Half Three Point Formation on the King George Island is 71.33±0.3 Ma. Correlative study of εND(T)-147Sm/144Nd, 143Nd/144Nd-87Sr/86Sr, 87Sr/86Sr-Sr and 87Sr/86Sr-K2O/(K2O+Na2O) indicated that the volcanic rocks were chiefly derived from the depleted mantle source and generally were not mixed crust materials. Of the samples 6 were given the mean Sm-Nd model age (TDMNd) of 443.3±20.6 Ma possibly indicating the age of chemical variation event in the magma source of the study area. Features of the trace elements indicated that the rocks from the Half Three Point Formation are of typical eale-alkaline volcanic suite and similar to those from the Tertiary volcanic rocks of the Fildes Peninsula, being the same products of the island-arc volcanic activity.
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The Zhongshan Station of China is located in the Larsemann Hills, East Antarctica. Low pressure granulite facies gneisses together with late granites are outcroped in the region. Three biotite samples from a garnet segregation, a syenogranite and a granite-pegmetite were measured with 40Ar/39Ar incremental heating technique. Biotites from the garnet segregation give an 40Ar/39Ar plateau age of 504±1Ma. Biotites from the syenogranite yield an 40Ar/39Ar plateau age of 494±1 Ma. Biotites from the granite-pegmatite give an 40Ar/39Ar plateay age of 486±1Ma. They verify 500 Ma thermal event called "Pan African event" by previous K-Ar and Rb-Sr data. They are cooling ages of the biotites when the paleogeotherm of the area droped to the K-Ar closure temperature for biotite.
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A preliminary analysis of some characteristics of the radiation components is made by using the surface radiation data obtained from February 1990 to January 1991 at Zhongshan Station. The result shows that the fluxes of direct radiation and global radiation are strong with higher atmospheric transparency, and the surface can absorb large amount of radiation energy in warm season. The surface loses heat energy in cold season due to the seasonal variations of the surface albedo and shortwave radiation. The variation of net longwave radiation is related to cloud amount and surface air temperature. The property of net radiation is similar to other Antarctic coastal stations but differs greatly from Antarctic inland area.
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The data used in this paper were acquired at 19 quantitative dredging stations and 4 trawling stations during the three crusies of the 4th Chinese Antarctic Research Expedition for investigating the shallow sea benthos in Great Wall Bay, in the period from December 1987 to March 1988. Based on environmental characteristics, diversity of species composition and the eveness of interspecific distribution of individuals, cluster methods were used to divide the investigated area into three benthic community distribution areas. The structures of the various communities were further divided into 3 structure types, namely, high diversity, intermediate diversity and low diversity types. From the study of the relationship between community structure and environmental factors it was pointed out that there was an extremely close relationship between benthic communities structure and the stability of the bottom types and sediments, whereas in sea areas where the depth gradient is not large, there is no obvious relationship between benthic communities structure and depth gradient.
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Samples of phytoplankton were obtained in February, 1985, in Great Wall Bay, Antarctica. Among the 31 species of phytoplankton identified, the cold-water species rank highest in proportion. The cell number of phytoplankton averaged 162.5×104 cells/m3 in the bay. The most dominant species are
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The aim of the study is to investigate the existing form and the partitioning pattern of fluoride in krill (Euphusia superba) by analysing the fluoride and other elements in various part of krill, primarily to approach the potential concentrating mechanism and the effect of fluoride in krill on the geochemical characteristics of fluoride in the Antarctic ecoenvironment. The results of the study show that the amount of flouride in various part of krill has a considerable difference. Most of fluoride is concentrated in the carapace, up to 4028 μg/g, and the head and legs, respectively 2724 μg/g and 2828 μg/g. The muscle contains the least flouride with amount of 226 μg/g. The amount of fluoride in whole freeze -dried krill is averagely 1232 μg/g, which indicates that the functional position of fluoride in krill is mainly located at the crust. Only a few of fluoride is found in the chitin of the carapaces (200 μg/g), which exhibits that fluoride in the carapaces exists mostly in the form of the nonchitious constitutent. In addition, the variation and concentration of flouride is related closely to some other elements such as P, Ca. Thus, fluoride in the carapaces is likely to exist as the form of the inorganic salt with P and Ca. It is also estimated frorn the study that a slightly higher concentration of fluoride in seawater and lower in sediment of the area relative to other oceans is possibly affected by the concentration of fluoride in the huge storage of krill in the area. The bioprocesses and precipitation with relation to the activity of krill should be very important and key sectoin to the geochemical cycling of the fluoride in Antarctic ocean.
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Analyzing the information on benthic organisms and geochemistry, obtained from the Chinese First Expedition on Antarctic Ocean and its succeeded works and comparing with that of other oceans, this paper shows that in the circumstances of the researched area benthic organisms are rich. However, the prodsperity of the organisms is limited below 5-10 cm of the profiles in which the environment is mainly dominated by sulfate reducing reaction. On the condition of low temperature in Antarctic Ocean, the solubility of carbonates is higher than that of other latitudes of oceans, but the concentration of calcium in overlying water and pore water of the benthic environment is not higher than that in other oceans, which results in the difficulty for the crustaceas and mollusks to obtain sufficient calcium carbonate to form their solid shell as well as to bring about the lower ratios of these animals both in abundance and biomass in the researched ocean. Futhermore, there is a positive relationship between the distribution of sedentary polychaetes and temperature in overlying waters. That might demonstrate that the animals had still not quite adapted to the bitterly cold of Antarctic Ocean. Besides, research proposes that although there is no microorganism being detected below the depth of 5 cm in M6 station, there happens sulfate reducing reaction, so at least there should be sulfate respiring bacteria existed below the depth.
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