中文摘要：

本文利用电子探针微区分析技术（EPMA）,首次分析了采自贵州瓮安北斗山磷矿区陡山沱组外壁呈瘤状及多边形板片状的磷酸盐化球状化石的元素地球化学含量,包括常量元素氧化物含量和部分稀土元素含量。经初步对比发现：具瘤状及板片状外壁的两类球状化石,由内至外常量元素含量的变化趋势大体相似,表明归入同一生物大门类的可能性较大;与磷块岩全岩样品相比,球状化石中除了P、Ca含量更高以外,Na、Ni、Zn和Cl有较高的含量,而且S含量和轻稀土元素Ce等含量均偏高,可能表明球状化石在趋于弱还原的沉积环境中被磷酸盐化保存;K、Al、Mg、Ti、Mn、Fe2＋和Si等含量均显著低于围岩。由于还缺乏后生动物的相关对比资料,目前还不能为球状微体化石的生物学属性争议提供元素地球化学方面的确切对比意见,但分析的结果不倾向于归属藻类、硫细菌和海绵动物。这方面的尝试为深化球状化石的亲缘关系研究提供了新途径和新材料。

英文摘要：

The Ediacaran Doushantuo Formation in Weng＇an and Fuquan areas of the Guizhou Province in southern China hosts high-grade phosphorus ore deposits and exceptionally well-preserved phosphatic microfossils that are commonly less than 1 mm in diameter. Earlier studies attributed these fossils to algae or acritarchs. In the last decade,researchers found that the spherical microfossils,in a large proportion,show metazoan embryonic development features with early cleavage stages. Thus these spherical microfossils have been considered as diploblast or triploblast embryos and resting eggs of early animals. However,reliable fossils similar to blastula,gastrula embryos,fossils of larvae after hatching,and particularly,the corresponding body fossils of these animal embryos have never been found in the relevant strata. This phenomenon challenges the interpretation that these globular microfossils are animal embryos. Because the major uncertainty on these fossils is whether they are animals or plants,a detailed geochemical analyses across the fossils may help to reveal the differences （between animal and plant） in the composition of cell membrane / wall and cell inclusions,the pattern of physiological metabolism,and the phosphatized mechanisms in particular depositional environments. On this basis and in combination with morphological comparison with the Cambrian microfossils and modern metazoan embryos,elemental geochemistry across the spherical microfossils （ ＂embryos＂） of the Weng＇an biota may provide new information for better understanding the genetic affinity of the Doushantuo globular fossils. In this paper,the author analyzes the microfossils collected from Weng＇an and Fuquan areas in Guizhou by electron probe micro-analyzer （EPMA） to obtain trace elemental geochemistry across the globular fossils. For comparison purposes,two types of fossils have been analyzed,including fossils with tumor-like outer wall and those with polygonal plate-shaped outer wall. Comparing results from these fossils and th