An early ecosystem of Archean tidal microbial mats (Moodies Group, South Africa, ca. 3.2 Ga)
An early ecosystem of Archean tidal microbial mats (Moodies Group, South Africa, ca. 3.2 Ga)
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DOI：
10.1130/g30101a.1
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发表时间：
2009-10-01
期刊：
影响因子：
5.8
通讯作者：
Heubeck, Christoph
中科院分区：
文献类型：
--
作者：
Heubeck, Christoph
中太古代穆迪群（南非巴伯顿绿石带，加利福尼亚州）的丰富微生物垫。3.2 Ga）在几乎无泥的环境中与粗粒和砾石砂岩紧密互层。它们显然生长在边缘海洋和可能的陆上沿海和潮汐环境中。典型的沉积构造包括封闭层理、气体或流体逃逸构造、砂火山、生物垫隆起、斑片状硅化微层积岩和微生物砂屑砾岩。它们表明，在高能量、高沉积速率的环境中，机械上坚韧的微生物垫快速生长，这可能是早期海底硅化作用的结果。这些观察结果扩大了对太古代微生物垫和早期地球生命栖息地的了解。如果潮汐环境在太古代比今天更广泛，那么广泛的潮间带环境中的生物垫可能有助于形成大量的沙子。
Abundant microbial mats from the Mesoarchean Moodies Group (Barberton Green-stone Belt, South Africa, ca. 3.2 Ga) are densely interbedded with coarse-grained and gravelly sandstones in a nearly mud-free setting. They apparently grew in marginal marine and possibly subaerial coastal and tidal environments. Characteristic sedimentary structures include anastomosing bedding, gas or fluid escape structures, sand volcanoes, biomat doming, patchy silicified microstromatolites, and microbial sand-chip conglomerates. They indicate rapid growth of mechanically tough microbial mats, possibly aided by early seafloor silicification, in a high-energy, high-sedimentation-rate environment.The observations expand the knowledge of the habitat of Archean microbial mats and life on early Earth. If tidal environments were more widespread in the Archean than today, biomats in extensive intertidal settings may have contributed to immobilize large volumes of sand.