Shell composition of Terreneuvian tubular fossils from north‐east Sichuan, China
Shell composition of Terreneuvian tubular fossils from north‐east Sichuan, China
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DOI：
10.1111/pala.12268
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发表时间：
2017-01
期刊：
影响因子：
2.6
通讯作者：
Y. Pang;M. Steiner;Cen Shen;Mingshi Feng;Li Lin;Dingkun Liu
中科院分区：
文献类型：
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作者：
Y. Pang;M. Steiner;Cen Shen;Mingshi Feng;Li Lin;Dingkun Liu
鉴定小壳化石（SSF）的主要成分对解释小壳化石动物群的进化具有重要意义。利用光镜、扫描电镜和能量色散X射线能谱研究了在四川东北部发现的Terreneuvian管状ssf的特征和成分。岩石薄片显示，壳的化学成分以碳酸钙为主，磷、硅、黄铁矿含量较少。大多数由碳酸钙组成的管状壳具有明显的层状结构。发现了磷化、黄铁矿化、硅化、碳酸钙重结晶等作用，破坏了原壳的层状结构。大多数用醋酸处理过的化石都是磷铸型或斯坦克氏型，其中一些保留了壳的有机纹理作为磷铸型。四川东北部的Terreneuvian管状ssf最初主要由碳酸钙组成；事实上，大多数terrenevian的小型骨骼化石似乎具有原始的钙质成分。化石铸模或内芯化石由磷酸盐组成，与局部埋藏过程有关。
Identification of the primary constituents of small shelly fossil (SSF) shells is important for explaining the evolution of SSF faunas. The characteristics and constituents of Terreneuvian tubular SSFs found in north‐east Sichuan, China, are revealed using light microscopy, scanning electron microscopy and energy dispersive X‐ray spectroscopy. Petrographic thin sections indicate that the chemical composition of the shells is mainly calcium carbonate with smaller amounts of phosphorus, silica and pyrite. Most of the tubular shells composed of calcium carbonate have a distinct layered structure. Evidence of replacement of the original shell by phosphatization, pyritization and silicification, and recrystallization of calcium carbonate have been found, all of which destroyed the shell's original layered structure. Most fossils treated with acetic acid are phosphatic casts or steinkerns, with some preserving organic textures of the shell as phosphatic casts. We conclude that the Terreneuvian tubular SSFs from north‐east Sichuan were originally composed mainly of calcium carbonate; indeed, most Terreneuvian small skeletal fossils appear to have had an originally calcareous composition. The fossil casts or internal core fossils are composed of phosphate, which is related to local taphonomic processes.