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Fluid inclusions have recorded the history of degassing in basalt. Some fluid inclusions in olivine and pyroxene phenocrysts of basalt were analyzed by micro-thermometry and Raman spectroscopy in this paper. The experimental results showed that many inclusions are present almost in a pure CO2 system. The densities of some CO2 inclusions were computed in terms of Raman spectroscopic characteristics of CO2 Fermi resonance at room temperature. Their densities change over a wide range, but mainly between 0.044 g/cm3 and 0.289 g/cm3. Their micro-thermometric measurements showed that the CO2 inclusions examined reached homogenization between 1145.5℃ and 1265℃ . The mean value of homogenization temperatures of CO2 inclusions in basalts is near 1210℃. The trap pressures (depths) of inclusions were computed with the equation of state and computer program. Distribution of the trap depths makes it know that the degassing of magma can happen over a wide pressure (depth) range, but mainly at the depth of 0.48 km to 3.85 km. This implicates that basalt magma experienced intensive degassing and the CO2 gas reservoir from the basalt magma also may be formed in this range of depths. The results of this study showed that the depth of basalt magma degassing can be forecasted from CO2 fluid inclusions, and it is meaningful for understanding the process of magma degassing and constraining the inorganogenic CO2 gas reservoir. 相似文献
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通过四次对青冈林洞、洗线洞和水响洞的调查,共获37种动物。各种类数量优势分别为有光带的蚁蛉幼虫、蕈蚊,弱光带和黑暗带水域的红点髭蟾蝌蚪以及洞壁的斑灶马。2001年10月和2003年3月,青冈林洞、洗线洞和水响洞分别有动物群落15、13和10种类型,优势群落为斑灶马、红点髭蟾蝌蚪和蚁蛉幼虫。动物的取食、隐蔽、繁殖、栖息等环境在不同时期的变换引起这一区域洞穴动物在种类、数量和空间分布等的变化,人类活动则加大了生境的差异。食物-陷阱法可用于部分动物的相对数量的调查。 相似文献
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G. R. KATTEL 《山地科学学报》2009,6(3):228-239
Representativity of biota in the biosphere also have similar significance in the lithosphere after their death. Recently, taphonomic representation of biota in the lithosphere has been widely used for minimizing the biases in palaeo-environmental reconstructions including global climate change. In September 2001, a sediment trap was installed at the central area of the Loch Coire Fionnaraich （LCFR）, a small, oligotrophic mountain loch in northwest Scotland for a taphonomic study of cladoceran zooplankton. The trap was emptied on a seasonal basis, where an average 0.14 g dry material was recovered in each season, January, May and August 2002 respectively. A sediment core was also taken from near the sediment trap location. The top 0.5 cm section, the ＇core＇ was used for a comparative study with the trap sediment samples. The planktonic Cladocera consisted of Bosmina coregoni and appeared to have excellent preservation in the trap assemblages. Moreover, some common littoral Cladocera such as Alonella excisa and Aloha guttata appear to be less well preserved in the fossil assemblages. Large littoral taxa such as Eurycercus lamellatus and Aloha quadrangularis were rare in the trap but relatively common and well preserved in the sediment-water interface. It is suggested that taphonomic processes play a dominant role on deposition of fossil remains of Cladocera and caution should be taken while inferring the past environmental changes whilst using fossil assemblages recovered from the lake centre as a representation of the entire cladoceran community in the lake. 相似文献