Lateral variability in shallow marine ichnofabrics: implications for the ichnofabric analysis method
Lateral variability in shallow marine ichnofabrics: implications for the ichnofabric analysis method
复制标题
浅海海洋结构的横向变异：对结构分析方法的影响
DOI：
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发表时间：
2007
影响因子：
2.7
通讯作者：
D. McIlroy
中科院分区：
文献类型：
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作者：
D. McIlroy
遗迹学分析通常在野外和岩心研究中进行，通常在垂直测井序列中进行。这项工作记录了详细的遗迹组构研究的结果，两个高度生物扰动砂岩床分开的泥岩，在厚，下侏罗纪继承的约克郡海岸，英国。这两个砂岩层含有丘状交叉分层的残余物和罕见的双壳类和箭石生物碎屑。生物扰动强烈，遗迹化石的多样性相当可观。遗迹化石包括Teichichnus rectus、Teichichnus isp. A，Thalassinoides isp.，Palaeophycus heberti，Diplocraquillum parallelum，Rhizocorallium，Rosselia socialis，Schaubcylindrichnus isp.，Chondrites isp.，Planetarisp.和Phycosiphon incertum。遗迹组构进行了研究，在5米的间隔平行于现代的悬崖线，这是平行于推断的侏罗纪古海岸线。结果表明，即使在一个相对简单的沉积环境，如风暴影响的货架，有相当大的斑块遗迹组构。这一观察结果与现代海底的研究一致。遗迹组构斑块的影响是广泛的，但最重要的是表明，在使用遗迹组构分析区域内的相关性需要谨慎。
Ichnological analysis, commonly undertaken both in the field and in core studies, is generally carried out in vertical logged successions. This work documents the results of a detailed ichnofabric study of two highly bioturbated sandstone beds separated by a mudstone, within the thick, Lower Jurassic succession of the Yorkshire coast, UK. The two sandstone beds contain relicts of hummocky cross-stratification and rare bioclasts of bivalves and belemnites. Bioturbation of the beds is intense and the diversity of trace fossils is considerable. Trace fossils present include Teichichnus rectus, Teichichnus isp. A, Thalassinoides isp., Palaeophycus heberti, Diplocraterion parallelum, Rhizocorallium, Rosselia socialis, Schaubcylindrichnus isp., Chondrites isp., Planolites isp. and Phycosiphon incertum. Ichnofabrics were studied at 5 m intervals parallel to the modern cliff-line, which is parallel to the inferred Jurassic palaeo-coastline. The results demonstrate that there is considerable patchiness to ichnofabric even in a comparatively simple depositional setting such as a storm-influenced shelf. This observation is in line with studies of the modern sea floor. The implications of patchiness in ichnofabric are broad-ranging, but most importantly suggest that caution is needed in the use of ichnofabric analysis for intra-regional correlations.