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Ichnofabric Index
The Droser-Bottjer ichnofabric index is a method used to quantify the degree of bioturbation in a sedimentary rock. It involves grading the amount of trace fossil activity on a scale of 1–6; a value of 1 indicates that bioturbation is entirely absent, whereas the highest grade would involve a Bed (geology), bedding plane containing over 60% trace fossil cover. Application Ichnofabric index can be applied in either a vertical or horizontal aspect. The vertical component provides an indication of the interplay between physical and chemical aspects of the environment and the degree of biological activity. The vertical ichnofossil index is harder to measure; it involves quantifying the amount of disturbance to the original sedimentary fabric. References Trace fossils {{trace-fossil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helminthopsis01
''Helminthopsis'' is the ichnogenus of a type of trace fossil that is found preserved on the bedding planes of fine-grained sedimentary rocks. It is characterized by short, curvilinear, non-branching, parallel-sided, unlined traces on bedding surfaces. It is thought to represent the submarine feeding trails of an invertebrate organism that worked the surface of muddy substrates in search of food. Because ''Helminthopsis'' traces never cross over themselves, the ichnogenus is distinguished from similar traces assigned to the ''Gordia'' ichnogenus. The similar sounding, but now obsolete, ichnogenus ''Helminthoida'' refers to a somewhat similar trace characterized by regular, back-and-forth meanders, whereas ''Helminthopsis'' traces are irregular. See also * Trace fossil * Ichnology References Trace fossils {{trace-fossil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
