ENVIRONMENTAL ARCHAEOLOGY IN NORTH-EAST AND CENTRAL WALES (CLWYD-POWYS)
Astrid
Caseldine
(CADW Environmental Archaeologist, University of Wales, Lampeter)
Mike
Walker
(University of Wales, Lampeter)
A. Caseldine
(1990): Environmental Archaeology in Wales. CADW Welsh Historic
Monuments & St David's University College, Lampeter
A. Caseldine
(2003): Environmental
Archaeology in Wales. 2nd edition,
CADW Welsh Historic Monuments & University of Wales, Lampeter (in
preparation)
Strength of
palaeoenvironmental studies is the ability to provide a record of both
CONTINUITY and CHANGE within the landscape
Important to distinguish
between research focusing on PALAEO- ENVIRONMENTAL RECONSTRUCTION and research
which is more overtly concerned with ENVIRONMENTAL ARCHAEOLOGY.
The former may or may not
include an archaeological dimension; the latter invariably will. The human
element is crucial in the latter.
Evidence available at a
range of spatial scales: SITE > LOCAL > REGIONAL
At one end of the spectrum
is the SITE SURVEY which invariably involves excavation; at the other the
LANDSCAPE SURVEY which may or may not include an excavation component, but
which may be linked to one
For example: FUNERARY &
RITUAL SITES project: combination of archaeological excavation/survey and
palaeoenvironmental analysis
ENVIRONMENTAL
ARCHIVES
Existing archives: Lakes, mires and
bogs ) Off-site
Buried
soils ) Off-site and on-site
Tufas ) Off-site and on-site
Ditch
fills ) On-site
Posthole
fills ) On-site
Middens ) On-site
Cave
sediments ) On-site
Potential archives (opportunities):
Fluvial sequences:
Under-explored in NE and C Wales
(a) Rivers as indicators of climate change
(b) Rivers as sites of human occupation
(c) Rivers as archives of human impact on the
landscape: alluviation and incision
Multidisciplinary approach involving archaeologists and
geomorphologists: variety of scales: catchment scale -> individual reaches
Work in the Ystwyth, but potential in the Elan Valley, in the Severn,
and in some of the North Wales Valleys
The coastal archive
(a) Coastal wetlands and human activity
(b) Midden sites
(c) Dune-building episodes and phases of sand-blow
Again, some work undertaken (e.g. Prestatyn are) but potential yet to
be realised
Key to both of the above: involvement of archaeologists with earth
scientists
THE
ENVIRONMENTAL RESOURCE BASE
1. Pollen analysis: Key technique
Strengths: (a) Found in a range of deposits
(b) Stratified sequences - vegetation change
through time
(c) Matrix can often be dated by 14C
(d) Preservation ) NE & C
(e) Wide range of potential sites
) Wales
Weaknesses: (a) Taphonomic
problems
(b) Inadequate records (Lateglacial?) )
(c) Few high-resolution sequences ) NE
& C
(d) Few well-dated diagrams ) Wales
(e) Few long lowland records )
(f) Many sites independent of archaeology )
2. Plant macrofossils/Charcoal/Wood
remains
Strengths: (a) Natural (local) vegetation
(b) Evidence of human activity: on- and
off-site
(c) Evidence of agriculture: arable/pastoral
(d) Site context evidence
(e) Preservation
Weaknesses: (a) Too few sites
so far investigated ) NE and C
(b) Few integrated studies ) Wales
3. Animal bones
Strengths: (a) Evidence of farming
(b) Evidence of diet
Weaknesses: (a) Preservation
4. Mollusca )
5. Insects )
6. Diatoms )
7. Ostracods ) Importance
8. Testate amoebae
(rhizopods) ) of
9. Marine fossils
(foraminifera, etc) ) integrated
10. Lipids (animal fats, plant
oils, waxes, resins, etc) ) studies
11. Soils (phosphates, soil
micromorphology) )
12. Sediments (particle size,
magnetic susceptibility, etc))
13. Stable isotopes )
14. Documentary sources (Historic period) )
1. Radiocarbon
Strengths: (a) Wide applicability
(b) Recent developments: calibration (INTCAL; OXCAL)
AMS
- single entity dating
(c) Dating of on-site and off-site events:
basis for correlation
Weaknesses: (a) Analytical
precision
(b) Contamination and related problems
(c) Cost
(d) NE & C Wales: few well-dated sites ) e.g.
Waun Fignen
few multi-dated sites )
Felen
many 'bulk sediment' dates
2. Dendrochronology
Strengths: (a) Age in calendar years
(b) Basis for inter-site correlation
(c) Dendroclimatology
(d) Coastal peats ) ?
NE Wales
Weaknesses: (a) Master curves
required
(b) Few sites (if any) so far investigated
3. Pb210 (very recent
sediments)
4. TL/OSL (sands; pottery)
5. U-series (cave sediments)
6. Amino-acid racemisation
(marine molluscs)
7. Cosmogenic nuclides
8. Tephrochronology
THREATS
1. Drainage of wetland sites
2. Liming of sites
3. Afforestation of uplands
4. Road developments ) Although potential here for
5. Industrial developments ) developer
funding
SOME
KEY RESEARCH QUESTIONS/RESEARCH ISSUES IN NE and C WALES
1. The climatic/vegetational sequence over
the longer timescale, especially during the Lateglacial (Late Palaeolithic).
2. Effects of climate change
on human activities (eg. in Late Bronze Age; in Dark Ages, in Medieval period): agricultural
practices; farm abandonment;
cultivation limits.
3. Evidence for Mesolithic
human impact - landscape management?
4. When did pastoralism
become established in NE and C Wales?
5. Origins of agriculture in NE and C Wales
- when did cereal cultivation begin?
6. Spatial and temporal
changes in prehistoric woodland clearance (upland/lowland contrasts: Cambrian Mountain; lowland valleys etc).
7. Human agencies in upland
peat formation in C Wales?
8. Upland/lowland contrasts
in prehistoric agricultural activity (e.g. Brecon
Beacons and Wye Valley; Plynlimon and Severn Valley).
9. Regional contrasts in farming regime
during Bronze Age and Iron Age (cereals; pastoralism?).
10. The development of field
systems during the 2nd and 1st millennia BC.
11. Impact of Roman occupation on agricultural
activities in C and NE Wales?.
12. Environmental impact of prehistoric mining,
etc.
13.
Environmental conditions at and surrounding funerary and ritual monuments?
14.
Role of plant and animal remains in burial and ritual practice.
More integrated studies needed:
(a) EXCAVATION and SURVEY (b) MULTI-PROXY
approaches
(c) ARCHAEOLOGISTS
& EARTH SCIENTISTS