CHAMBERS OF EPIPHYTON THALLI IN MICROBIAL BUILDUPS, ZHANGXIA FORMATION (MIDDLE CAMBRIAN), SHANDONG PROVINCE, CHINA
CHAMBERS OF EPIPHYTON THALLI IN MICROBIAL BUILDUPS, ZHANGXIA FORMATION (MIDDLE CAMBRIAN), SHANDONG PROVINCE, CHINA
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DOI：
10.2110/palo.2006.p06-103r
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
J. Woo;S. Chough;Z. Han
中科院分区：
文献类型：
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作者：
J. Woo;S. Chough;Z. Han
摘要通过对附着藻体在微生物堆积过程中的微观形态变化进行研究，探讨了影响附着藻体形态和钙化过程的控制因素，以及这些因素对钙化微生物鉴定的意义。中国山东张夏组（中寒武世）的微生物碳酸盐岩包括凝块岩、叠层石和附生植物堆积，以及微生物和后生动物群落的联合体。附生植物是植物的刚性骨架，根据其分枝的特征可分为四种类型。类型1由直径为1.75 μ m的致密微晶树枝状棒状体组成，形成形和分室的叶状体。2型分枝粗约80 μ m，以横节为特征。类型3由细的、直径约50 μm的微晶枝组成，形成圆形的菌体。类型4的特征是横向排列，形成扇形菌体的分支管。所有的形态类型都有二分的分枝丝作为基本的生长模式。丛状的叶状体在附生生物丘的内部占优势，而室状的叶状体，这是孤立的，连接和分层，是常见的外部部分。这些物理能量条件，如水流或波浪，控制着分枝的密度、长度和鞘的厚度以及菌体的繁殖方式。附生菌体的腔室轮廓类似于雷纳西斯的腔室轮廓，尽管腔室壁中的分支杆和管的内部结构不同。当钙化和成岩作用去除或消除腔壁的内部结构时，菌体变得类似于肾。附生菌体的形态变化和随后的质地变化可以导致鉴定为不同的钙化微生物类群。
Abstract Microscopic morphologic variations of Epiphyton thalli in microbial buildups were examined in order to detail controlling factors on morphology and calcification processes, and their implications for identification of calcified microbes. Microbial carbonate of the Zhangxia Formation (Middle Cambrian), Shandong Province, China comprises thrombolites, stromatolites, and Epiphyton buildups, as well as consortia of microbial and metazoan communities. Epiphyton, a rigid framework of the buildups, is subdivided into four types based on characteristics of the branches. Type 1 consists of ∼75-μm-diameter dendritic rods of dense micrite that form bush-shaped and chambered thalli. Type 2 has ∼80-μm-thick branches characterized by transverse segments. Type 3 consists of thin, ∼50-μm diameter micritic branches that form round thalli. Type 4 is characterized by laterally arrayed, branching tubes that form fan-shaped thalli. All morphologic types have bipartite branched filaments as a basic growth pattern. Bush-shaped thalli are dominant in the inner part of the Epiphyton bioherms, while chambered thalli, which are solitary, connected, and tiered, are common in the outer part. Such physical energy conditions as currents or waves control the density, length, and sheath thickness of the branches and propagation pattern of the thalli. Chamber outlines of Epiphyton thalli resemble those of Renalcis, although internal structures of the branching rods and tubes in the chamber walls are distinct. Thalli become similar to that of Renalcis when calcification and diagenesis remove or obliterate the internal fabric of the chamber wall. Morphologic variations of Epiphyton thalli and subsequent textural changes can result in identification as different groups of calcified microbial taxa.