Taphonomy Document sent by Dr Nicholas Flemming

TAPHONOMY FORUM 1 - 22.Oct.2010

DRAFT FOR COMMENT ON THE SPLASHCOS TAPHONOMY FORUM

Note from Nic Flemming:

I refer to the discussion during the plenary meeting in Rhodes regarding a “Taphonomy Forum” in the SPLASHCOS website.

The following note is intended to start the discussion on the analysis of seabed prehistoric taphonomy in WG2, but anyone can join in, especially those in WG1.

The notes below have been copied in advance to Jan Harff, Tine Missiaen, Ole Gron, Delminda Moura, Ehud Galili, and I have modified this first draft in the light of comments received.

If SPLASHCOS has an unstructured random discussion on the website as a totally open-ended forum it is unlikely that there will be sufficient convergence of ideas to produce a useful report by the next SPLASHCOS meeting in April 2011.

This note suggests some boundary conditions for the discussion, sets out some headings or topics that we think are important, and the subject is now open for coments, totally new proposals, additions, deletions, comments, and so on. Please let us know what you would like to see as a report or set of recommendations on the study and analysis of prehistoric seabed taphonomy. It is a very serious subject, and we have to make some progress on this if SPLASHCOS is to be successful. It should be possible in 6 months to produce a summary web-document which will be an asset to SPLASHCOS and Deukalion.

Everybody is welcome to make contributions on this topic!

A. BOUNDARY CONDITIONS

The definition of “taphonomy” for the purposes of the SPLASHCOS Forum is the process of changes which occur to an archaeological or anthropogenic prehistoric site after it has been abandoned on land, during the phases of marine inundation, its survival on the seabed, and its phases of erosion, sedimentation, exposure, discovery and possible destruction.

The subject of Taphonomy for the purposes of this Forum does not include:-

• Prediction of the locations most likely to be occupied by hominins.
• General analysis of coastal and shallow water marine geomorphology.
• Site management or conservation
• The preservation or burial of entire landscapes

Reasoning: Site prediction is a huge subject involving all aspects of cultural determinism, archaeology on the grand scale, and a profound knowledge of different types of site origination in different cultures, environments and periods. Maybe there should be a forum on site prediction, but we should not mix it up with taphonomy in the simplest sense, which is a much more achievable goal.

There are text books on coastal processes such as “Beaches and Coasts” by Richard Davis and Duncan Fitzgerald:

http://www.amazon.com/Beaches-Coasts-Richard-Davis-Jr/dp/0632043083

Or similar books by Bird and others. We strongly recommend that people read these books, but we do not need to re-invent the wheel. This subject is well provided for in the established literature. SPLASHCOS and Project Deukalion will, in the course of their work, add greatly to our understanding of past evolution and dynamics of coastlines during rapid climate change, but this is not properly the subject of archaeological taphonomy in the present context.

Site management policies will derive, in part, from an understanding of the site formation and taphonomy, and the “Taphonomy Forum” will provide a service to experts concerned with site management, but, again, let’s try and keep the subject sharply defined and constrained, so that we can work towards an achievable goal, without distractions.

The preservation of landscapes at the scale of tens to hundreds of km is a different subject from that of the survival of buried archaeological materials. While we wish to study anthropogenic material in the context of landscapes, the key factor is to prove by archaeological survey and possible excavation that the landscape was genuinely occupied by hominins. This Forum is about the taphonomy of the archaeological materials in localised deposits, not the whole surface of the continental shelf.

B. SUB-HEADINGS FOR CLASSIFYING ASPECTS OF PREHISTORIC SITE CONTINENTAL SHELF TAPHONOMY

1. Temporal succession of the continental shelf taphonomic process
   i) Deposition of anthropogenic materials and effects on land and on the coast.
   ii) Changes occurring on land, and possible change of climate, before marine inundation.
   iii) The marine transgression impact on the archaeological deposits, especially the impact of the surf zone and storm waves and currents.
   iv) Intermediate sea water depth, impact of waves, currents, sedimentation, bioturbation, etc.
   v) Present day marine processes, impact of waves, currents, sedimentation, bioturbation, industrial impacts, tourism, etc.
   vi) Processes of erosion and destruction
   vii) Events leading to discovery and analysis, visual detection, trawling, industrial recovery, scientific search.

2. Outline classification of cultural period/technology of origin of the site material
   i) Middle Palaeolithic
   ii) Late/Upper Palaeolithic
   iii) Mesolithic
   iv) Neolithic
   v) Chalcolithic/Bronze Age

   Reasoning: The boundaries between these cultural periods may be debatable, and may change from time to time, and the dates of transition are different in different geographical regions. Nevertheless, the oceanographic and geomorphological processes operate on deposits in ways which depend upon the nature of the deposits. Thus it is useful to define the site-type in cultural/technological terms, rather than absolute dates. A shell midden responds differently from a heavy flint core, which is different from a Mesolithic hut post, or a Bronze Age street.

   This approach could be altered, and we can discuss the option of using fixed dates for the transition between site types.

3. Oceanographic exposure, fetch, and tidal range
   i) High energy, long fetch, high tidal range, e.g.- Atlantic/Arctic.
   ii) Medium energy, e.g.- North Sea, Channel/Manche/Irish Sea, open Mediterranean coasts, Black Sea.
   iii) Low energy, restricted fetch, e.g., Mediterranean marginal seas, Mediterranean climate, Adriatic, Aegean.
   iv) Low energy, restricted fetch, northern climate, e.g.- Baltic.

   Note: The effect of this broad classification will be worked out in detail when we include coastal configuration and climate. Rather than words like low and high we should adopt rigid quantitative definitions of wave and current climatology. In practice, the oceanographic parameters which impact on a site should be evaluated in detail for the initial inundation through to the modern conditions.

4. Dominant climate during history of the site
   i) Arctic, glacial.
   ii) Periglacial
   iii) Temperate
   iv) Warm temperate
   v) Mediterranean
   vi) North African.

   Note: These headings need elaboration into a more precise and technical classification. The climatic conditions at a site obviously change substantially during a glacial cycle, so that two extremes could be allocated to each site. Suggestions and references to established classifications invited.

5. Coastal topography and micro-environment (at time of deposition and now? Sequence? )
   i) Linear straight coast.
   ii) Coastal gradient, onshore-offshore, from vertical to 1:1000
   iii) Fjord coast
   iv) Steep or Cliff coast, non-karstic
   v) Karstic coast
   vi) Ria coast
   vii) Estuary
   viii) Archipelago, sheltering islands
   ix) Lagoonal;, sand bars, sand spits
   x) Prograding, active sedimentation
   xi) Deltaic
   xii) Eroding.
   xiii) Marsh, peat formation, organic deposits.
   xiv) Sand dunes, kurkar.
   xv) Sediment classification, mud to gravel, sorting.
   xvi) Erosional terrace
   xvii) River bank
   xviii) Coral or vermettid terrace
   xix) Cave, karstic solution pit.
   xx) etc,

   Note: I am grateful to Delminda Moura for the concept of a “Morpho-dynamic trap” for archaeological deposits. This concept captures the idea that the detailed shape of the coast and the distribution of wave-current energy in the locality determine whether the archaeological deposits survive or are destroyed. The concept applies to all scales. The ria harbours of the Vigo area of Spain create Morpho-dynamic traps, as do peat beds in the North Sea, or caves in a limestone cliff in the Mediterranean.

   We should check with Bird or Davis and Fitzgerald to make these categories fit agreed international lists of coastal classifications and features, if they exist.

   The micro-environment and the combined effect of climate and oceanographic exposure on the micro-environment, determine the history of survival. We should be able to identify types of sites which are known to have survived in many of these categories.

6. Deposited items and site assemblages…..this could be a long list!
   Note: It is premature to consider here a complete list of items which are known to have survived in submerged marine prehistoric sites, but we should consider some such inventory later. The range is enormous, from burials, lithics, carved bones, food remains, seeds, fibres, clothing, shells, hut foundations, canoes, paddles, fish weirs, wells, etc., etc. This can be elaborated later, possibly with sub-headings.

   Since the same types of artefact or anthropogenic signal may occur in different cultural periods this section could be classified by type of artefact, or by period, or as a grid of both.

   Palaeolithic items and assemblages:……..

   Mesolithic items and assemblages: Hearths, hut foundations, post holes, canoes, log boats, shells, shell middens, food debris and bones, plant food remains, human bones, seeds, nuts, lithics, debitage, hafted tools, wooden implements, fish hooks, etc…

   Neolithic items and assemblages: (Pre-pottery and pottery)…..

   Chalcolithic/Bronze Age items and assemblages: Burials, skeletons, hearths. lithics, figurines, carvings, stone walls, roads and tracks, coarse pottery, fine pottery, storage jars, shipwrecks (within harbours or occupied sites), metallurgical items, tools, fabrics, ropes, mats, etc….

Etc.

C. PRELIMINARY DISCUSSION, METHODOLOGY

We need to consider hypothetical sites of all types and combinations of conditions listed in section B, and assess whether materials will be conserved in situ, scattered slightly but still identifiable as a concentration of artefacts, or scattered and broken up so completely that only a few individual items will survive and completely out of context after transporting significant distances.

Three major of areas of agreement are needed if we are to succeed in converging towards a report document:

1. Have we got the definition of Taphonomy right?

2. Are there standard classifications or typologies which we should use for describing coastlines, climate/vegetation zones, archaeological artefacts, phases of taphonomic burial and change, etc? If there are pre-existing standards and lists, then that will save time, and make our work more compatible with other studies.(Even if we cannot define them all now). Please suggest established classifications of all types.

3. What is the best way of combining factors to study sites and regions? We need to develop dozens, maybe a hundred or more, of scenarios or worked examples, where we look at particular environments and types of deposit, and then run prototype sea level+ waves+ topography+ climate+ sediment supply over the site and calculate likely outcomes. These examples should include well-studied sites where the models are calibrated against reality, and hypothetical sites where we examine what is likely to happen to a site of a certain age west of Shetland, in the Gulf of Riga, the Sea of Azov, or west of Mallorca. How best to do this?

D. CONCLUSIONS

Please post comments, ideas, and suggestions on this forum!

Nic Flemming.

Downloads

• Taphonomy Forum (Word DOC file)