5600年形成的石化木  

A 5600-year-old fossilized wood

作　　者：袁林喜[1] 孙立广[1] 吴自军[1] 张庶元[2] 

机构地区：[1]中国科学技术大学地球与空间科学学院,安徽合肥230026 [2]中国科学技术大学结构成分分析中心,安徽合肥230026

出　　处：《中国科学技术大学学报》2008年第1期26-32,共7页JUSTC

基　　金：中科院知识创新工程(KZCX3-SW-151)

摘　　要：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.Fossils are usually preserved in aged strata, and the time span of their formation remains unclear. Here we report that a fossilized wood, collected from the intertidal zone of Zhujiajian Island, Zhejiang Province, China, has a radiocarbon age of 5 600 cal yr B P, which indicates that it is undergoing the fossilization process and probably the youngest fossilized wood ever found to date. The results of elemental geochemistry and microbial mineralogy analyses on this fossilized wood show that it was very likely formed by the process of Fe and Mn differentiation and mineralization under the influence of microbial activities. These findings may provide new insights into the formation of fossils and exogenous ores of Fe and Mn.

关 键 词：石化木 元素地球化学 微生物矿物学 微生物成矿 朱家尖岛 浙江省 

分 类 号：P593[天文地球—地球化学]