1 / 13

Trace Fossils

Trace Fossils. ichnofossils. Tracks and Trails . These features result from organisms moving across the sediment as they walk, crawl, or drag their body parts through the sediment. Burrow Marks.

sanura
Download Presentation

Trace Fossils

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Trace Fossils ichnofossils

  2. Tracks and Trails • These features result from organisms moving across the sediment as they walk, crawl, or drag their body parts through the sediment.

  3. Burrow Marks • Any organism that burrows into soft sediment can disturb the sediment and destroy many of the structures • If burrowing is not extensive, the holes made by such organisms can later become filled with water that deposits new sediment in the holes.  • Such burrow marks can be excellent top and bottom indicators.

  4. TRACE FOSSILS • Biogenic sedimentary structures are formed through the activities of animals and plants and vary widely from indistinct disruptions of bedding/laminations (bioturbation) to discrete trace fossils (ichnofossils). • The term ichnofabric refers to the sediment’s texture and internal structure arising from bioturbation and a bioturbation index [from 0 (no disruption) to 6 (complete disruption)] is often used to describe the degree of disruption. • Trace fossils are best considered in terms of their mode of formation: crawling, grazing and resting (on bedding surfaces) and feeding and dwelling (within the beds).

  5. TRACE FOSSILS • ♦ crawling traces: trails, uncomplicated pattern; linear or sinuous. • ♦ grazing traces: more complicated surface trails, symmetrical or ordered pattern; coiled, radial, meandering. • ♦ resting traces: impression of where animal rested during life (but not a fossil mold). • ♦ dwelling structures: simple to complex burrow systems but without suggestion of systematic working of sediment; burrows can be lined or pelleted. • ♦ feeding structures: simple to complex burrow systems commonly with well-organised and defined branching pattern indicating systematic reworking of sediment.

  6. CRUZIANA RUSOPHYCUS DIPLICHNITES

More Related