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产于贵州瓮安埃迪卡拉系陡山沱组磷块岩中的“瓮安生物群”是认识早期生命起源与演化的重要窗口。因为其特殊的磷酸盐化作用,其中的球状化石内部保存了大量精细的细胞甚至亚细胞结构,但保存这些化石的磷酸盐化作用机理尚不清楚。因此,本文采用绿藻门下团藻和空球藻为实验对象,通过改变pH、温度、氧气含量等实验条件,探索藻类在不同埋藏环境下的保存状况,为早期磷酸盐化化石的埋藏机制提供证据。实验结果显示藻类在不同实验条件下的保存潜力差距较大,相同环境下两种藻类所体现的保存潜力也不一致,但都具备足够的保存潜力;空球藻细胞在埋藏过程中出现褶皱变形,但在不同条件下的形态学差异并不明显;团藻的繁殖体形态与瓮安生物群中的一类多细胞球状化石的细胞分裂形式十分相似;早期状态一致的同种藻类不管在相同还是不同的实验条件下其个体直径大小均表现出较强的差异性。本次实验模拟自然状态下的埋藏环境,因此实验现象可能在现实埋藏过程中重现,通过实验得出以下结论：磷酸盐化的埋藏环境中藻类具备足够的保存潜力;磷酸盐化会导致生物获得自身以外的形态学信息;在不同的埋藏学环境下保存的磷酸盐化球状化石的直径大小会有差异;胚胎状化石与磷酸盐化的现生藻类... 相似文献
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Effect of Phosphatization on Element Concentration of Cobalt-Rich Ferromanganese Crusts 总被引：4，自引：1，他引：3
E. H. De CARLO 《《地质学报》英文版》2005,79(3):349-355
1 Introduction Co-rich ferromanganese crusts occurring on submarine guyots have received much attention from scientists since the beginning of the 1980’s because they are enriched in Co, Mn, Pt, and rare earth elements (REEs), and have large potential mineral resources, occurring as they do on topographic highs relative to polymetallic nodules in the C-C (Clarion-Clipperton) zone (Halbach et al., 1982, 1989; Hein et al., 1992, 1999; Usui and Someya, 1997; Yamazaki and Sharma, 1998, 2000… 相似文献
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Noble Gas Isotopic Compositions of Cobalt-rich Ferromanganese Crusts from the Western Pacific Ocean and Their Geological Implications 
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下载免费PDF全文 SUN Xiaoming XUE Ting HE Gaowen YE Xianren ZHANG Mei LU Hongfeng WANG Shengwei 《《地质学报》英文版》2007,81(1):90-98
1 Introduction Submarine metallic mineral resources consist mainly of polymetallic nodules and cobalt-rich ferromanganese crusts. Despite being discovered much later than the former, the latter are becoming one of the most important submarine polymetallic ore resources, because they containmany valuable metallic elements such as Co, platinum group elements (PGE), rare earth elements (REE), Ni and Cu, besides high contents of Fe and Mn (He et al., 2001). The Co-rich crusts are widely distr… 相似文献
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In the present paper, iodine(I), iron(Fe), manganese(Mn), cobalt(Co), phosphorus(P) and calcium(Ca)contents in three ferromanganese crusts from the Pacific Ocean are measured by spectrophotometric method and inductively coupled plasma atomic emission spectrometers(ICP-AES) to investigate the contents and distribution of iodine in ferromanganese crusts. The results show that iodine contents in three crusts vary between 27.1 and 836 mg/kg, with an average of 172 mg/kg, and the profile of iodine in the three crusts all exhibits a two-stage distribution zone: a young non-phosphatized zone and an old phosphatized zone that is rich in I, P and Ca. The iodine content ratios of old to young zone in MP5D44, CXD62–1 and CXD08–1 are 2.3, 3.4 and 13.7, respectively.The boundary depths of two-stage zone in MP5D44, CXD62–1 and CXD08–1 locate at 4.0 cm, 2.5 cm and 3.75 cm,respectively, and the time of iodine mutation in three crusts ranges from 17–37 Ma derived from 129 I dating and Co empirical formula, which is consistent with the times of Cenozoic phosphatization events. The present study shows that the intensity of phosphatization is the main responsible for the distribution pattern of iodine in the crusts on the basis of the correlation analysis. Consequently, iodine is a sensitive indicator for phosphatization. 相似文献
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磷酸盐化的发生会造成多金属结壳主要成矿元素的贫化,总体上抑制结壳的生长.磷酸盐化作用呈幕式在太平洋内发生,已有研究将其发生期次与多金属结壳中的磷酸盐化层位及其P、Ca等元素地球化学特征对应,为结壳的年代厘定提供证据.然而,由于磷酸盐化多次发生且在结壳多个层位中显现,首先需要厘定出较为可靠的多金属结壳年代框架,才能与磷酸... 相似文献
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