2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 168-8
Presentation Time: 3:00 PM

TO WHAT EXTENT DOES DEPOSITIONAL ENVIRONMENT AFFECT PARTICLE MORPHOLOGY IN CHARCOAL ASSEMBLAGES?


CRAWFORD, A.J., Department of Geography, University of Exeter, Level 7 Laver Building, North Park Road, Exeter, EX4 4QE, United Kingdom and BELCHER, Claire M., Department of Geography, University of Exeter, Exeter, EX4 4PS, United Kingdom, a.j.crawford@exeter.ac.uk

Charcoal particles, produced in wildfires and preserved in sediments, are a valuable indicator of past fire activity and environmental change. One source of this information is their morphology, which can indicate the botanical affinity of the source material, and may also affect the suitability of different methods for measuring charcoal quantity. Previous work on this subject has focused on Late Quaternary lake sediments, which often present an optimal environment for preservation of the charcoal record. However other sedimentary archives may be studied, which may relate to different timescales and different taphonomic processes, and lead to differently preserved morphologies.

We have extracted mesocharcoal particles (> 125 µm) from a Mid-Late Holocene peat core, and from Mesozoic sedimentary rocks, and used image analysis to characterise the morphological variation in the charcoal present in these samples.

We will consider the effects of depositional environment and age on morphology, and whether these result in differential preservation of morphological information. We will assess whether such differences have implications for the quantification of charcoal particles, and thus for reconstructions of levels of fire activity, and whether they may affect the potential for broad taxonomic identification.