The Tayuan(Cu-Mo)-Pb-Zn deposit is located in the northern part of Daxinganling,NE China.Lenticular ore body occurs in the skarn zone.The skarn minerals mainly include garnet,pyroxene,epidote and wollastonite.Electron...The Tayuan(Cu-Mo)-Pb-Zn deposit is located in the northern part of Daxinganling,NE China.Lenticular ore body occurs in the skarn zone.The skarn minerals mainly include garnet,pyroxene,epidote and wollastonite.Electron microprobe analysis shows that the end member of garnet is mainly andradite(Ad_(62-97)Gr_(11-45),the pyroxene is mainly diopside,and epidote is mainly clinozoisite.These characteristics indicate that the Tayuan polymetallic skarn deposit is mainly calcareous skarn.Sometimes the content zonation can be observed in garnets.With one garnet crystal,content is shifty from the core to the rim.In general,the iron content in the core is higher than in the edge.The content in the garnet shows that the garnet in the Tayuan deposit formed from weak oxidation in alkaline environment with the oxygen fugacity increasing,suggesting that the hydrothermal fluid evolved from an acidic to a slight alkaline state.In the Tayuan polymetallic deposit,the ratio of Mn/Fe in pyroxene is about 1.3,and of Mg/Fe,it is about 2.The components of garnet in the Tayuan deposit plot in the field of the typical skarn Zn,Cu,Mo deposits in the world.展开更多
On the basis of digital records from Tayuan well, we study coseismic effects of water temperature caused by remote earthquakes. The records show that the water temperature changes are consistently following the proces...On the basis of digital records from Tayuan well, we study coseismic effects of water temperature caused by remote earthquakes. The records show that the water temperature changes are consistently following the process of drop-rise-recovery regardless of focal mechanism or epicentral directions. The step amplitude of water temperature increases with the increase of earthquake magnitude, and decreases with the decrease of epicentral distances. They have rather well correlation. Water temperature rising after earthquake is influenced by water level variations. Fi- nally, the mechanisms of coseismic effects of water temperature have been discussed. Preliminary study shows that accelerated convection and mixing of different temperature water in virtue of seismic wave are the main causes of water temperature drops. Seismic wave accelerates water convection, which causes warm water to move up from deeper part of the well and cold water to go down from the upper part. Temperature probe will detect water temperature drops at early stage. After the occurrence of earthquake, as the fluctuation of water level gradually quiets down, water temperature near the probe begins to rise.展开更多
1 Introduction Daxinganling region is one of the most important nonferrous metal metallogenetic province(Wu et al.,2011;Li et al.,2014).The northern Daxinganling was a geological blank area in China formerly(Li et al....1 Introduction Daxinganling region is one of the most important nonferrous metal metallogenetic province(Wu et al.,2011;Li et al.,2014).The northern Daxinganling was a geological blank area in China formerly(Li et al.,2017).However,the region has a huge resource potential.Forty metal deposits have been found in the area recently,with展开更多
Co-seismic responses of the groundwater level and temperature in the Tayuan well of 68 earthquakes (M_S≥7.0) from January 2004 to September 2007 were analyzed. Results show that the Tayuan well has a strong ability t...Co-seismic responses of the groundwater level and temperature in the Tayuan well of 68 earthquakes (M_S≥7.0) from January 2004 to September 2007 were analyzed. Results show that the Tayuan well has a strong ability to record large earthquakes worldwide, and the co-seismic response shows a pattern of water level oscillation → temperature decrease→ oscillation stop → temperature resumption. Further analyses indicate that the amplitude of the water level and temperature change is not only concerned with the epicenter distance and magnitude, but is also related to the temporal state of aquifer while the seismic wave arrives. Mechanisms of water level oscillation, temperature decrease, water level oscillation stop and temperature resumption are discussed, with the results from previous research on the co-seismic response mechanisms analyzed. These include gas escape, heat diffusion and cold water seepage. Results show that a single mechanism could not explain the co-seismic response of the Tayuan well water level to multiple earthquakes; the results were garnered from a variety of jointly acting mechanisms.展开更多
基金supported by the Natural Science Foundation of China(No.41203039)
文摘The Tayuan(Cu-Mo)-Pb-Zn deposit is located in the northern part of Daxinganling,NE China.Lenticular ore body occurs in the skarn zone.The skarn minerals mainly include garnet,pyroxene,epidote and wollastonite.Electron microprobe analysis shows that the end member of garnet is mainly andradite(Ad_(62-97)Gr_(11-45),the pyroxene is mainly diopside,and epidote is mainly clinozoisite.These characteristics indicate that the Tayuan polymetallic skarn deposit is mainly calcareous skarn.Sometimes the content zonation can be observed in garnets.With one garnet crystal,content is shifty from the core to the rim.In general,the iron content in the core is higher than in the edge.The content in the garnet shows that the garnet in the Tayuan deposit formed from weak oxidation in alkaline environment with the oxygen fugacity increasing,suggesting that the hydrothermal fluid evolved from an acidic to a slight alkaline state.In the Tayuan polymetallic deposit,the ratio of Mn/Fe in pyroxene is about 1.3,and of Mg/Fe,it is about 2.The components of garnet in the Tayuan deposit plot in the field of the typical skarn Zn,Cu,Mo deposits in the world.
基金National Natural Science Foundation of China(40372131)the Key Projects Required by National 10th Five-year Plan(2004BA601B01-02-02).
文摘On the basis of digital records from Tayuan well, we study coseismic effects of water temperature caused by remote earthquakes. The records show that the water temperature changes are consistently following the process of drop-rise-recovery regardless of focal mechanism or epicentral directions. The step amplitude of water temperature increases with the increase of earthquake magnitude, and decreases with the decrease of epicentral distances. They have rather well correlation. Water temperature rising after earthquake is influenced by water level variations. Fi- nally, the mechanisms of coseismic effects of water temperature have been discussed. Preliminary study shows that accelerated convection and mixing of different temperature water in virtue of seismic wave are the main causes of water temperature drops. Seismic wave accelerates water convection, which causes warm water to move up from deeper part of the well and cold water to go down from the upper part. Temperature probe will detect water temperature drops at early stage. After the occurrence of earthquake, as the fluctuation of water level gradually quiets down, water temperature near the probe begins to rise.
基金supported by the Natural Science Foundation of China(No.41203039)
文摘1 Introduction Daxinganling region is one of the most important nonferrous metal metallogenetic province(Wu et al.,2011;Li et al.,2014).The northern Daxinganling was a geological blank area in China formerly(Li et al.,2017).However,the region has a huge resource potential.Forty metal deposits have been found in the area recently,with
基金Research Grant from the Institute of Crustal Dynamics,CEA under the Contract No.ZDJ2008-04the Joint Earthquake Science Foundation (A07084),China
文摘Co-seismic responses of the groundwater level and temperature in the Tayuan well of 68 earthquakes (M_S≥7.0) from January 2004 to September 2007 were analyzed. Results show that the Tayuan well has a strong ability to record large earthquakes worldwide, and the co-seismic response shows a pattern of water level oscillation → temperature decrease→ oscillation stop → temperature resumption. Further analyses indicate that the amplitude of the water level and temperature change is not only concerned with the epicenter distance and magnitude, but is also related to the temporal state of aquifer while the seismic wave arrives. Mechanisms of water level oscillation, temperature decrease, water level oscillation stop and temperature resumption are discussed, with the results from previous research on the co-seismic response mechanisms analyzed. These include gas escape, heat diffusion and cold water seepage. Results show that a single mechanism could not explain the co-seismic response of the Tayuan well water level to multiple earthquakes; the results were garnered from a variety of jointly acting mechanisms.
