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30 December 1995, Volume 7 Issue 4 Previous Issue    Next Issue
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STUDY ON THE RELATIONSHIP BETWEEN THE CRYSTALLINE CONE NUMBER AND THE GROWTH OF THE ANTARCTIC KRILL 1995, 7 (4):  4-9.  Abstract ( 1715 )   PDF (387KB) ( 1260 )   Correlation between the body length and the number of the crystalline cone in the compound eye of the Antarctic krill Euphausia superba Dana was examined.From the samples collected in the late summer, it shows that there is an apparent exponential relationship between crystalline cone and the body length.From the laboratory population, it seems that when the krill shrink, the crystalline cone number does not decrease.The ratio of crystalline cone number to body length offers a method for detecting the effect of shrinking in natural populations of krill. Related Articles | Metrics

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RESEARCH ON THE GLACIATION OF THE LARSEMANN HILLS, EAST ANTARCTICA 1995, 7 (4):  10-19.  Abstract ( 1286 )   PDF (274KB) ( 1250 )   The Larsemann Hills are a series of gneiss islets and peninsulas extending into Prydz Bay, between the Amery Ice Shelf and the Sorsdal Glacier. The hills are ice free and form an area of approximately 200km 2 at 69°21′ -69° 28′ S and 76°00′-76°25′E on the Ingrid Christensen Coast of Princess Elizabeth Land, East Antarctica. The hills had been covered by ice sheet as early as Early Oligocene, and the ice sheet was the thickest in the Late Oligocene. Since the Miocene, ice sheet began to be thinner and retreat but covered the hills also. The glaciation scale of the quaternary is far inferior to the Tertiary. The thickness of ice sheet exceeds 170m and the margin thickens about 30 km at 18 ka B.P.. The time of deglaciation and exposed rocky land has been outlined at 10 ka B.P..The islets of the Larsemann Hills were ice free by 6.5ka B.P., and the rate of retreat was 2-3 m/a. By 5.0ka B.P.,50% of the hills were exposed and ice retreated at 1.0-1.5m/a. After 5.0 ka B.P. the rate of retreat did not exceed 0.8-1.0 m/a to its present position. Related Articles | Metrics

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LABORATORY STUDY ON THE FECUNDITY OF ANTARCTIC KRILL 1995, 7 (4):  20-25.  Abstract ( 1245 )   PDF (209KB) ( 1117 )   The spawning habits including brood size,the number of broods,ovarian development of spawned females of 53 gravid females of Antarctic krill, Euphausia superba Dana,were investigated on board ship JiDi during the austral summer of 1992/1993 in the Prydz Bay region,the Indian sector of the Southern Ocean. Most of the females spawned only once. The brood size ranged from 225 to 5919 eggs with average of 2132. Only two females spawned secondly 5 and 7 days after the first spawning with brood size of 516 and 492 respectively. There were no or only a few (average of 32) mature oocytes remained in spawned ovaries. The regeneration of oocytes were not observed during 1-39 days after the spawning. The brood size increased with the increasing of body weight and body length, but the correlation were poor. Related Articles | Metrics

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40 Ar/ 39 Ar AND K Ar DATING OF THE VOLCANIC ROCKS FROM THE NORTHERN COAST OF KING GEORGE ISLAND, WEST ANTARCTICA 1995, 7 (4):  26-37.  Abstract ( 1395 )   PDF (337KB) ( 1320 )   The volcanic and intrusive rocks from the northern coast of King George Island have been firstly dated with 40 Ar/ 39 Ar dating technique, K Ar dilute and laser microarea 40 Ar/ 39 Ar isochron dating techniques. Systematically dated results provide that the volcanic activities in studied area lasted from Late Cretaceous to the end of Eocene epoch and the major eruptions occurred in Eocene. Northeastwards younging of rocks along the northern coast suggests a gradual migration of the volcanic centers in King George Island, which correspond to the regularly distributed time space pattern of the volcanic activities on the South Shetland Islands. The intrusive rock was formed later than the eruptive rocks, that implies the granodiorite was from the same magma resource as basaltic lava and underwent differentiation. These new datawith such high precision will give a great support either for collating and stipulating the stratigraphical time or to the research on tectonomagmatic process. Related Articles | Metrics

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INSPIRATION FROM STUDY OF ANTARCTIC METEORITES Ⅵ. INVESTIGATIONS OF MARTIAN METEORITES AND IMPLICATIONS FOR COSMOCHEMISTRY 1995, 7 (4):  38-55.  Abstract ( 1513 )   PDF (559KB) ( 1314 )   Samples from another Earth like planet of the solar system is now available due to discovery of Martian meteorites.Up to 10 Martian meteorites covering 4 petrographic types have been found so far,including 4 meteorites collected in the Antarctic area. In this review paper,discovery on petrology,mineralogy,bulk chemical composition,isotopic compositions of light elements and noble gases,and chronology of the Martian meteorites are summarized. In addition,a preliminary discussion is concerned on chemical compositon of the Martian mantle,Martian magamatism and chemical weathering on the Martian surface,based on the study of Martian meteorites. Related Articles | Metrics

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VERTICAL AND SEASONAL VARIATIONS IN BIOMASS OF ICE ALGAE IN THE VICINITY OF ZHONGSHAN STATION,ANTARCTICA 1995, 7 (4):  56-67.  Abstract ( 1408 )   PDF (345KB) ( 1100 )   The ice algae communities at three sites near Zhongshan Station (69°22′24″S,76 °22′40″E),east Antarctica were monitored from April to December 1992. The maximum ice thickness was 1.74m in November and covered snow was less than 30cm in depth through the year. 2 or 3cm brown layers occurred in the bottom ice in later April and November,with highest chlorophyll a values of 88.3 and 2810mg/m 3 respectively,and the comparing cell numbers were 3.5×10 6 and 1.21×10 8cells/l. The maximum integrated chlorophyll a value was 59.7mg/m 2 in November and the values had never exceeded 6mg/m 2 before mid October. Most of the biomass occured in the bottom ice and more than 95 percent of it was concentrated in the bottom 15cm ice layer during ice algae bloom. The dominant diatoms included Nitzschia lecointei,N. barkleyi and N. cylindrus in austral autumn,and Amphiprora kjellmanii,Berkeleya rutilans,Nitzschia lecointei in austral spring,and had some difference depending on the sites and environmental conditions. The results show that the composition of dominant species of ice algae and the biomass in austral spring were similar to that of other fast ice sites in east Antarctica but very different from that of sub Antarctica. Related Articles | Metrics

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THE U Pb DATING OF ZIRCON IN THE MAFIC GRANULITE FROM THE LARSEMANN HILLS, EAST ANTARCTICA AND ITS GEOLOGICAL IMPLICATIONS 1995, 7 (4):  68-73.  Abstract ( 1484 )   PDF (271KB) ( 1212 )   The U Pb isotopic dating of zircon in the mafic granulite which derived from mafic cumulate from the Larsemann Hills, East Antarctica, suggested that a granulite facies metamorphic event earlier than the Pan African event (500Ma) possibly occurred in the middle of Neoproterozoic in this region. The U Pb discordia of zircon in the mafic granulite mainly composed of Opx Cpx Pl Qtz is 772.4+71.1/-48.0(2σ)Ma.Combining with the field evidence, this result possibly represents the earlier mid pressure granulite facies metamorphic event recognized in this region and maybe corresponds to the Rodinia event. Related Articles | Metrics

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A TIPYCAL SAMPLE OF IONOSPHERIC DISTURBANCE CAUSED BY MAGNETOSPHERIC CONVECTION 1995, 7 (4):  74-82.  Abstract ( 1468 )   PDF (507KB) ( 1422 )   Using data of EISCAT,f 0F2 from ionosondes of Zhongshan Station in Antarctica and station chain in China,the ionospheric disturbance on May 2-3,1991 is analyzed.The features representing processes of electrodynamic and dynamic couplings during a magnetic storm are compared carefully.It shows that in this sample the disturbance is mainly caused by magnetospheric convection.Analysis of geomagnetic data from stations around the world indicates,viewing from another angle,that the coupling mechanism discussed here is reasonable. Related Articles | Metrics

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CHROMOSOME OBSERVATION OF 3 MOSS IN THE KING GEORGE ISLAND, ANTARCTICA 1995, 7 (4):  83-85.  Abstract ( 1340 )   PDF (74KB) ( 1024 )   This paper reported chromosome number of 3 moss in the King George Island, Antactica:1. Drepanocladus uncinatus n=14;2. Chorisodontium aciphyllum n=10; 3. Polytrichastrum alpinum n=7. Related Articles | Metrics