This is a very interesting video Amaia. What it shows so vividly applies only in certain types of sedimentary environments (SBK is a prime example);
their common denominator is hyper-aridity. D Pearsall has already described this phenomenon and the conditions under which it may have a significant negative impact in her Paleoethnobotany volume (2nd edition, 2000, pp.82-84):
“dry sieving [should be used] instead of water flotation in soils that are habitually dry … Charcoal that is rarely wetted in the soil may “explode”
on contact with water.” (and the she goes on to describe a range of methods and sieving apparatus that can help addressing such situations)
Were it the case that this is a “problem that researchers working in southwest Asia OFTEN face“
(my emphasis), then all of us would have had very little to go about re: adequately retrieved primary data sources. Any arguments against using flotation need to be fully qualified and tested on a site-by-site basis. I am sure that all archbots would agree
that we really don’t need uncooperative field directors hiding behind excuses such as “flotation destroys everything therefore it is not necessary”.
All the best,
Eleni
___________________________________________
Dr. Eleni Asouti
Reader in Environmental Archaeology
Director of Postgraduate Research
Department of Archaeology, Classics and Egyptology,
University of Liverpool
12-14 Abercromby Square
Liverpool L69 7WZ, UK
Tel: (+44) 151 79 45284
http://www.liv.ac.uk/archaeology-classics-and-egyptology/staff/eleni-asouti/
From: The archaeobotany mailing list <[log in to unmask]>
On Behalf Of amaia arranz
Sent: 24 March 2018 13:18
To: [log in to unmask]
Subject: tuber exploitation and flotation
Dear all,
For those that are interested in
prehistoric underground storage organs (USO) here is a link to a recently published paper from a late Epipaleolithic site in Jordan (free download for 50 days):
https://authors.elsevier.com/a/1WmGB-4PRmL4X
I’m grateful to all the listmembers that contributed to this study in one way or the other.
In particular I'd like to draw your attention to the
supplementary video S1. This video was recorded to visualise a problem that researchers working in southwest Asia often face: the desintegration of plant remains during flotation. The video shows how wood charcoal and underground storage organs completely
desintegrate when they enter in contact with water. We would like to encourage people to pay attention to the flotation process, and in so doing limit the biases associated to sample processing.
Hope the results are useful for some of you,
With best wishes,
Amaia