Case Studies of Eco-geology on Typical Islands in Ny-(?)lesund, Arctic and Zhoushan Archipelage, Zhejiang
|School||University of Science and Technology of China|
|Keywords||Ny-Alesund in the Arctic Zhejiang Zhoushan Islands Ancient sea groove Intertidal Bacterial causes of iron minerals Fe-Mn -coated Dating back 9400 years Sudden cooling event Seabird populations Microbial mineralization REE enrichment|
In order to strengthen the comparative study of north and south poles, a better understanding of the response of the polar environment evolution of global change, and improve the theoretical system of this new field of research of the polar ice-free area ecological geology, in typical Arctic islands of Svalbard Orr the loose areas related research; discussed more ecological geology problems in order to expand the scope of the study of the ecological geology, the Zhoushan Islands in the East China Sea, a typical island also carried out related research. Slovakia match time Bergen Island the new 奥尔松古海 eclipse groove deposition profile in the Arctic and the Zhoushan Islands and ancient accumulation intertidal zone as research material carrier, the use of geochronology, sedimentology, geochemistry, isotope geochemistry, The paleoecology, geomicrobiology, microbial mineralization interdisciplinary theory and method, respectively Arctic the ancient sea recess sediments age, geochemical element content, organic carbon and nitrogen isotopes, inorganic carbon and oxygen isotope, particle size, Hunter whiteness. Microscale features leachate system element geochemistry and Zhejiang and ancient accumulation intertidal intertidal substances sulfur isotope intertidal micro characteristics of ferromanganese minerals, combined with multivariate statistical analysis, mathematical approach Arctic new 奥尔松古海 eclipse groove and Zhejiang Zhoushan Islands and ancient accumulation intertidal comprehensive ecological geology study, the main conclusions are as follows: (a) combination of Arctic the new 奥尔松古海 eclipse groove sediment sources The identify and sediment formation time determine, found early dating back 9400 years seabirds have already landed Bay and multiply in Wang Wansheng live. Holocene seabird historical research in the Arctic Ny-Alesund reported for the first time, has an important significance for the further study and understanding of the ecological history of the Arctic Svalbard seabirds; (b) by the new 奥尔松古海 eclipse concave in Arctic slot save the shells and debris the shell aragonite oxygen isotopic composition analysis and reconstruction of the ambient water temperature of 9,400 yr BP -0.52 ~ 4.78 ℃, about 1 degree higher than the modern environmental water temperature; shells of the large number of simultaneous death is likely to be caused by the sudden cooling event 9,400 yr BP. The incident is likely to be by the weakening of the sun radiation is driven positive feedback amplified by thermohaline circulation, and eventually led to the high Arctic sea-surface temperature fell sharply. The short but significant cooling event is widespread not only in Greenland, the North Atlantic, the Alps, Eastern Europe, the Northern Hemisphere, and in low latitudes, the southern hemisphere, and even distant Antarctic record shows that 9,400 yr BP abrupt cooling event is likely to be widespread; (c) AMS14C dating established the Arctic the new 奥尔松古海 erosion groove deposition the 70.118 cm chronology, explore a bit of the layer deposition mode, and extract behalf of guano typomorphic combination of elements, reconstruction the seabird populations change history. The results show that seabirds since 9400 years ago Log in Ny-ago period of 1860, its population has experienced two major stages: (I) the beginning of the landing, the seabird populations gradually increased in BP 7650 years or so to reach the maximum population; (II), and the subsequent 5800 years, the number of seabird populations experienced volatility :7650-6280 yr BP ,6280-4580 yrB.P. ,4580-2540yr BP 3 times. Further contrast seabird ecology of Svalbard in the sea surface temperature (SST) is not significantly limiting factor, the North Atlantic climate, especially Golf Gulfstream change will seabird ecology to form a decisive impact; (d) new Arctic 10-70 cm segment 奥尔松古海 eclipse groove deposited gravel accumulation of ice into a product of the Little Ice Age (LIA). Modern microorganisms into 0-10 cm segment of modern sediments since the 20th century, after the ice retreat of the Little Ice Age (LIA), related to the Ny-Alesund area of ??human activity; (e) of the Zhoushan Islands and ancient accumulation intertidal zone mine studies found buried ancient humus / organic acids that provide ideal living conditions for the addicted neutral iron-oxidizing bacteria Leptothrix ochracea Gallionella ferruginea, sulfate-reducing bacteria growth; mineralization product of the iron-oxidizing bacteria mainly aphanitic ferrihydrite and iron oxidizing bacteria mineralization process through different stages, until the entire cell was completely mineralized surface mineralization from the cell wall, cell internal part mineralization biogeochemical cycle of metal elements in the environment have an important the impact; sulfate-reducing bacteria in the intertidal belt abound in the environment, and to participate in Fe-S cycle, biologically induced extracellular mineralization; (f) of the Zhoushan Islands in China and ancient accumulation of intertidal studies have shown that with the Fe-Mn hydroxide pack cementation phenomenon, including red and yellow package objects mineral composition of the mineral composition of the layered manganite and hydrated water and goethite, black package objects pyrolusite, and Fe / Mn elements in the coated material is evenly distributed. Scanning electron microscopy to reveal the red and yellow packets litter the mineral in spheroids and spherical aggregates exist in the form, at the same time a large number of rod-shaped bacteria the community and bacteria seats also observed; black package be the mineral was in tiny serrated The disc-shaped crystals are arranged in an irregular honeycomb structure, moreover, the initial Mn hydroxide precipitate - hydrated pyrolusite crystal nodular cements been observed, was ellipsoidal. Black coated material in the presence of a large number of bacteria debris. Bacteria are likely to play an important role in the Fe-Mn hydroxides coated material formation process. Results show that the Fe-Mn package litter significant adsorption of Sc, V, Cr, Co, Ni, of Cu, Zn, Ba, particularly Co and Ni, can be used as the potential environmental bioremediation material distribution of trace metal elements. Fe-Mn-coated material has the MREE enrichment PAAS standardized REE mode, reveals its experienced two consecutive formation process: (1) Bulk Furuki release large amounts of humic acid by fermentation, humic acid role in base rock the release of a large number of minerals of Fe-Mn, Fe-Mn minerals in the form of humic acid complex state groundwater system to migrate to the intertidal zone, mixed with sea water, flocculation occurs, but this process does not occur to a significant REE fractionation ; flocculation process (2) or flocculation after seawater MREE preferentially adsorb to the formation of a precipitate of Fe-Mn hydroxide, resulting in the formation of Fe-Mn package enrichment MREE. Understanding of the characteristics of this study, micro package was for the Fe-Mn hydroxides, intertidal, shallow water environment of the Fe-Mn cycle and its REE and trace metals in the understanding of the behavior of great significance.