Zircon stability in silicate melts—which can be quantitatively constrained by laboratory measurements of zircon saturation—is important for understanding the evolution of magma. Although the original zircon saturation model proposed by Watson and Harrison (Earth Planet Sci Lett 64(2):295–304, 1983) is widely cited and has been updated recently, the three main models currently in use may generate large uncertainties due to extrapolation beyond their respective calibrated ranges. This paper reviews and updates zircon saturation models developed with temperature and compositional parameters. All available data on zircon saturation ranging in composition from mafic to silicic (and/or peralkaline to peraluminous) at temperatures from 750 to 1400 °C were collected to develop two refined models (1 and 2) that may be applied to the wider range of compositions. Model 1 is given by lnCZr(melt) = (14.297 ± 0.308) + (0.964 ± 0.066)·M − (11113 ± 374)/T, and model 2 given by lnCZr(melt) = (18.99 ± 0.423) − (1.069 ± 0.102)·lnG − (12288 ± 593)/T, where CZr(melt) is the Zr concentration of the melt in ppm and parameters M [= (Na + K + 2Ca)/(Al·Si)] (cation ratios) and G [= (3·Al2O3 + SiO2)/(Na2O + K2O + CaO + MgO + FeO)] (molar proportions) represent the melt composition. The errors are at one sigma, and T is the temperature in Kelvin. Before applying these models to natural rocks, it is necessary to ensure that the zircon used to date is crystallized from the host magmatic rock. Assessment of the application of both new and old models to natural rocks suggests that model 1 may be the best for magmatic temperature estimates of metaluminous to peraluminous rocks and that model 2 may be the best for estimating magmatic temperatures of alkaline to peralkaline rocks.
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The interaction between the cryosphere and atmosphere is an essential and extremely sensitive mutual action process on the earth. Due to global warming and the cryospheric melting, more and more attention has been paid to the interaction process between the cryosphere and atmosphere, especially the feedback of the cryosphere change to the atmosphere. A comprehensive review of the studies on the interaction between the cryosphere and atmosphere is conducted from two aspects: (1) effects of climate change on the cryosphere or responses of the cryosphere to climate change; and (2) feedback of the cryosphere change to the climate. The response of the cryosphere to climate change is lagging. Such a lagging and cumulative effect of temperature rise within the cryosphere have resulted in a rapid change in the cryosphere in the 21st century, and its impacts have become more significant. The feedback from cryosphere change on the climate are omnifarious. Among them, the effects of sea ice loss and snow cover change, especially the Arctic sea ice loss and the Northern Hemisphere snow cover change, are the most prominent. The Arctic amplification (AA) associated with sea ice feedback is disturbing , and the feedback generated by the effect of temperature rise on snow properties in the Northern Hemisphere is also of great concern. There are growing evidence of the impact of the Arctic cryosphere melting on mid-latitude weather and climate. Weakened storm troughs, steered jet stream and amplified planetary waves associated with energy propagation become the key to explaining the links between Arctic cryosphere change and atmospheric circulation. There is still a great deal of uncertainty about how cryosphere change affects the weather and climate through different atmospheric circulation processes at different spatial and temporal scales due to observation and simulation problems. 相似文献
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