Lateral Comparative Investigation of Stromatolites: Astrobiological Implications and Assessment of Scales of Control.
Lateral Comparative Investigation of Stromatolites: Astrobiological Implications and Assessment of Scales of Control.
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叠层石的横向比较研究：天体生物学意义和控制规模评估。
DOI：
10.1089/ast.2015.1388
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发表时间：
2016
期刊：
影响因子：
4.2
通讯作者：
F. Corsetti
中科院分区：
文献类型：
--
作者：
Y. Ibarra;F. Corsetti
控制层积物形成的过程--可能代表微生物过程的宏观表现和天体生物学研究的明确目标的结构--发生在不同的尺度上（局部与区域），但确定它们的相对重要性仍然是一个挑战，特别是对于古老的沉积物和/或太阳系其他地方发现的类似沉积物。我们建立在传统的多尺度水平的调查方法（微观，中观，宏观，大型），包括横向比较调查组成部分的罚款大规模的功能，以确定当地和/或非本地控制叠层石形态的相对意义，并在这个过程中，帮助限制微生物形成的主导影响。在横向比较研究的一个例子中，中新世巴斯托组的湖相微生物岩（加州）显示出两种主要的中孔织物：（1）泥晶带，其厚度急剧变化，并且不能在相邻的分米级亚单元之间直接追踪;以及（2）在亚单元之间惊人一致的亮晶纤维层，这表明亮晶纤维层的形成受到比亚单元之间的长度尺度更大的过程的影响（可能是湖泊化学）。来自英国三叠纪科瑟姆最上层的微生物岩，以米级土丘的形式出现，并含有一系列层压和树枝状中纤维。同样的层压/树枝状对联可以追溯到，不仅从一个土堆到另一个土堆，但超过100公里，表明区域规模的影响非常小的结构（微米到厘米），否则将不明显，没有横向比较的方法，并证明，规模的功能不一定规模的过程的范围。因此，横向比较研究和多尺度分析的结合可以提供一种有效的方法，用于评估整个岩石记录中对叠层石结构和形态的主要控制，并可能通过漫游者尺度分析（例如，火星）。
The processes that govern the formation of stromatolites--structures that may represent macroscopic manifestation of microbial processes and a clear target for astrobiological investigation--occur at various scales (local versus regional), yet determining their relative importance remains a challenge, particularly for ancient deposits and/or if similar deposits are discovered elsewhere in the Solar System. We build upon the traditional multiscale level approach of investigation (micro-, meso-, macro-, mega-) by including a lateral comparative investigational component of fine- to large-scale features to determine the relative significance of local and/or nonlocal controls on stromatolite morphology, and in the process, help constrain the dominant influences on microbialite formation. In one example of lateral comparative investigation, lacustrine microbialites from the Miocene Barstow Formation (California) display two main mesofabrics: (1) micritic bands that drastically change in thickness and cannot directly be traced between adjacent decimeter-scale subunits and (2) sparry fibrous layers that are strikingly consistent across subunits, suggesting the formation of sparry fibrous layers was influenced by a process larger than the length scale between the subunits (likely lake chemistry). Microbialites from the uppermost Triassic Cotham Member, United Kingdom, occur as meter-scale mounds and contain a characteristic succession of laminated and dendrolitic mesofabrics. The same succession of laminated/dendrolitic couplets can be traced, not only from mound to mound, but over 100 km, indicating a regional-scale influence on very small structures (microns to centimeters) that would otherwise not be apparent without the lateral comparative approach, and demonstrating that the scale of the feature does not necessarily scale with the scope of the process. Thus, the combination of lateral comparative investigations and multiscale analyses can provide an effective approach for evaluating the dominant controls on stromatolite texture and morphology throughout the rock record and potentially on other planets via rover-scale analyses (e.g., Mars).
COTHAM 大理石的微相：来自英国西南部上三叠世的管石碳酸盐微岩：答复
影响因子：
1.6
作者：
IBARRA Y
通讯作者：
IBARRA Y