16th April 2019
Event phone: 020 7408 2000
An Introduction to Applied Trace Fossil Analysis
Dr Andy Taylor (Skolithos Limited)
With thanks to Simon Gould (Mearns Geoscience Ltd), for this review
Thirteen participants gathered at the PESGB training facility in Central London on April 16th 2019 to attend this course, led by Andy Taylor of Skolithos Ltd with assistance from Andy Racey. The attendees were a mix of consultants, sedimentologists and staff development/exploration geologists. The PESGB’s new training facilities were ideal for the purpose and conveniently located a few minutes’ walk from Victoria railway station.
Trace fossil identification represents a daunting prospect for many of us as, often, the lack of detailed knowledge of individual species dissuades one from making a confident interpretation, despite there being abundant evidence of general biogenic activity. However, the information which can be gained from an ichnofabric is often the only true real-time snapshot of the depositional environment and so is invaluable in providing a complete interpretation. This course does a good job of addressing this issue. Andy used the day wisely and took the approach of focussing on the extraction of pertinent information that taxonomy can yield whilst interpreting core or outcrop, rather than focussing on the complexity of species names. Over the course of the day the group discussed, amongst other things, the taxonomical differences between dwelling, grazing, resting and predication traces, and what information this provides about depositional energy levels, substrate conditions and the palaeoenvironment.
The course contained very few slides, with the ones used comprising of many good quality photographic examples from outcrop and core material. Andy also provided many exemplary hand specimens for inspection, several of which were from classic localities which we will all have visited at some point in our careers. Not all examples were from shallow marine rocks– it was good to see examples from Devonian and Triassic continental rocks as well as Palaeocene turbidites. The course was centred around 3 main practical exercises, focussing on the use of hand specimens which allowed the participants to get their eyes into the main features. Specimens could be picked at random in some instances, which kept the exercises both interesting and challenging. Both Andy Taylor and Andy Racey ably assisted this with informative discussions with individuals over the samples. Reviewing these exercises afterwards seeded some intriguing discussions. One of these stressed the importance of understanding the nature of faunal colonisation when assessing both the source and reservoir potential of a shale. Another discussion centred around the use of ichnofabrics for defining correlatable, hiatal surfaces within sequences. These discussions emphasised that although trace fossils rarely provide an accurate dating constraint in the manner of plant or body fossil data, they have many other uses for subsurface correlation and need to be accounted for in any core description.
In summary, this well-organised course provided a great insight into a complex subject and, being practical based, provided basic skills which can be applied to core or outcrop data to improve an interpretation, and comes highly recommended.