化石通常赋存在年代久远的地层中,其形成所需的时间是一个尚不清楚的问题.对浙江省朱家尖岛发现的"石化木"———一种形似珊瑚的铁、锰质岩石,进行了元素地球化学、微生物矿物学等的研究,发现它们是在微生物成矿作用下,经Fe,M...化石通常赋存在年代久远的地层中,其形成所需的时间是一个尚不清楚的问题.对浙江省朱家尖岛发现的"石化木"———一种形似珊瑚的铁、锰质岩石,进行了元素地球化学、微生物矿物学等的研究,发现它们是在微生物成矿作用下,经Fe,Mn分异和矿化过程形成的."石化木"炭芯年龄为5 600 cal yr B P,这表明,该石化木正在进行化石化的过程,可能是迄今为止发现的最年轻的石化木.该发现对于解释这种自然现象并说明地球历史时期的化石及其形成过程和外生铁、锰矿床的成因有重要意义.展开更多
The bioleaching of two different types of low-grade copper tailings,acid-leaching tailings(ALT)and copper flotation tailings(CFT)by mixed moderate thermophiles,and the variation of mineralogical and microbiological ch...The bioleaching of two different types of low-grade copper tailings,acid-leaching tailings(ALT)and copper flotation tailings(CFT)by mixed moderate thermophiles,and the variation of mineralogical and microbiological characteristics during their dissolution processes were comparatively investigated.Results showed that bioleaching behaviors of the two types of tailings were significantly different.In ALT bioleaching,lower redox potential,higher[Fe3+]/[Fe2+]ratio and higher cell density in solution were obtained.These resulted in higher total copper,primary copper sulfide and secondary copper sulfide extractions,compared with CFT bioleaching.X-ray diffraction analysis suggested that gypsum and some metal organic complexes were detected in CFT bioleaching,which could cause the sluggish oxidation of sulphide minerals.The shifts of microbial community in the leachates and leaching residues varied greatly between ALT and CFT bioleaching.The percentage of iron-oxidizing bacteria in ALT bioleaching was higher than that of CFT,but the sulfur-oxidizing bacteria percentage was the opposite.The archaeon F.thermophilum L1 was detected in ALT but not in CFT.展开更多
文摘化石通常赋存在年代久远的地层中,其形成所需的时间是一个尚不清楚的问题.对浙江省朱家尖岛发现的"石化木"———一种形似珊瑚的铁、锰质岩石,进行了元素地球化学、微生物矿物学等的研究,发现它们是在微生物成矿作用下,经Fe,Mn分异和矿化过程形成的."石化木"炭芯年龄为5 600 cal yr B P,这表明,该石化木正在进行化石化的过程,可能是迄今为止发现的最年轻的石化木.该发现对于解释这种自然现象并说明地球历史时期的化石及其形成过程和外生铁、锰矿床的成因有重要意义.
基金Projects(31570113,41573072)supported by the National Natural Science Foundation of China
文摘The bioleaching of two different types of low-grade copper tailings,acid-leaching tailings(ALT)and copper flotation tailings(CFT)by mixed moderate thermophiles,and the variation of mineralogical and microbiological characteristics during their dissolution processes were comparatively investigated.Results showed that bioleaching behaviors of the two types of tailings were significantly different.In ALT bioleaching,lower redox potential,higher[Fe3+]/[Fe2+]ratio and higher cell density in solution were obtained.These resulted in higher total copper,primary copper sulfide and secondary copper sulfide extractions,compared with CFT bioleaching.X-ray diffraction analysis suggested that gypsum and some metal organic complexes were detected in CFT bioleaching,which could cause the sluggish oxidation of sulphide minerals.The shifts of microbial community in the leachates and leaching residues varied greatly between ALT and CFT bioleaching.The percentage of iron-oxidizing bacteria in ALT bioleaching was higher than that of CFT,but the sulfur-oxidizing bacteria percentage was the opposite.The archaeon F.thermophilum L1 was detected in ALT but not in CFT.
