Early Neolithic Agriculture in County Mayo, Republic of Ireland: Geoarchaeology of the Céide Fields, Belderrig, and Rathlackan
Erika B. Guttmann-Bond1,*, Jennifer A.J. Dungait2, Alex Brown3,
Ian D. Bull4, and Richard P. Evershed4
1Department of Archaeology, History and Anthropology, University of Wales, Trinity Saint David, College Street, Lampeter, Ceredigion, SA48 7ED, UK. 2Department of Sustainable Soils and Grassland Systems, Rothamsted Research-North Wyke, Okehampton, Devon, EX20 2SB, UK. 3The University of Reading, School of Human and Environmental Sciences, Department of Archaeology, Whiteknights Box 226, Reading, RG6 6AB, UK. 4Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, University of Bristol, School of Chemistry, Cantocks Close, Bristol, BS8 1TS, UK. *Corresponding author.
Journal of the North Atlantic, No. 30 (2016)
Abstract
The Céide Fields, Belderrig, and Rathlackan are extensive early Neolithic field systems in County Mayo, Republic of Ireland. The Céide Fields are thought to be the earliest field systems in Europe, and as such they are listed as a potential World Heritage site. For this project, the buried soils of the 3 sites were analyzed in order to determine the nature and extent of the prehistoric land use within the field systems. The aims were twofold: to identify material added as fertilizer, and to determine whether the land was used for pasture or for arable agriculture. Soil phosphates and bile acids from the Neolithic soils indicate low levels of input of herbivore dung, and also some human fecal material in the Céide Fields. The results suggest that the soils may have been fertilized with animal manure.
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Early Neolithic Agriculture in County Mayo, Republic of Ireland:
Geoarchaeology of the Céide Fields, Belderrig, and Rathlackan
Erika B. Guttmann-Bond1,*, Jennifer A.J. Dungait2, Alex Brown3, Ian D. Bull4, and Richard P. Evershed4
Abstract - The Céide Fields, Belderrig, and Rathlackan are extensive early Neolithic field systems in County Mayo, Republic
of Ireland. The Céide Fields are thought to be the earliest field systems in Europe, and as such they are listed as a
potential World Heritage site. For this project, the buried soils of the 3 sites were analyzed in order to determine the nature
and extent of the prehistoric land use within the field systems. The aims were twofold: to identify material added as fertilizer,
and to determine whether the land was used for pasture or for arable agriculture. Soil phosphates and bile acids from
the Neolithic soils indicate low levels of input of herbivore dung, and also some human fecal material in the Céide Fields.
The results suggest that the soils may have been fertilized with animal manure.
1Department of Archaeology, History and Anthropology, University of Wales, Trinity Saint David, College Street, Lampeter,
Ceredigion, SA48 7ED, UK. 2Department of Sustainable Soils and Grassland Systems, Rothamsted Research-North
Wyke, Okehampton, Devon, EX20 2SB, UK. 3The University of Reading, School of Human and Environmental Sciences,
Department of Archaeology, Whiteknights Box 226, Reading, RG6 6AB, UK. 4Organic Geochemistry Unit, Bristol Biogeochemistry
Research Centre, University of Bristol, School of Chemistry, Cantocks Close, Bristol, BS8 1TS, UK. *Corresponding
author - e.bond@tsd.ac.uk.
Introduction
The Céide Fields in County Mayo, Republic of
Ireland, are thought to be the earliest field systems
in Europe (Fig. 1; Caulfield et al. 1998). The Early
Neolithic co-axial fields are delineated by stone
walls that are now buried beneath up to 4 m of peat
(ibid.), which also seals an extensive buried mineral
soil. This geoarchaeological project was set up to
investigate the nature of prehistoric agriculture and
land use in these fields, and to compare the Irish evidence
with that of Britain and Continental Europe.
The origin of farming in Europe and the nature
of the social changes which accompanied it have
been the subject of considerable debate. Early arable
agriculture in Britain was once thought to have taken
place in small fields within temporary clearings
in the woodland (e.g., Case 1969), but subsequent
models suggested that Neolithic populations were
more sedentary (e.g., Barker 1985). The nature of
Neolithic settlement and subsistence was radically
reconsidered in the 1990s, when it was once again
suggested that settlement in Neolithic Britain was
shifting and impermanent (Thomas 1991, 1999;
Whittle 1996). The argument was largely based on
the absence of evidence for a sedentary lifestyle in
SW England. The Scottish and Irish evidence contrasts
with the mobile Neolithic model, and more
recent thinking is that there are strong regional
variations with differing degrees of mobility (Bradley
2003, Cooney 2003, Gibson 2003).
The Scottish evidence was reviewed by Barclay
(1997), who rejected the suggestion that the Neolithic
population in this region was anything but
permanent. Stone field boundaries, clearance cairns,
and long-lived settlement evidence suggest that
there was little movement about the landscape, unless
it was the seasonal movement of small groups.
The geoarchaeological evidence from Scotland suggests
that Neolithic agriculture took place in small
plots of very fertile land that were more like gardens
than fields (Guttmann 2005, Guttmann et al. 2004).
In NW Ireland, there is evidence for long-term
settlement and substantial ties to the land, including
many chambered tombs and extensive Neolithic
field systems bounded by stone walls. The Céide
Fields are the most well known of these sites, and
their 12-ha extent has been painstakingly surveyed
using steel probes to follow the walls beneath the
peat (Caulfield et al. 1998); the site is now a visitor
attraction and is currently under consideration to
become a World Heritage site. Other field systems
in the area have been revealed in peat cuttings, and
there are fields and house structures to the east of
the Céide Fields at Rathlackan (Byrne 1990) and to
the west at Belderrig (also called Belderg) (Caulfield
1978, Caulfield et al. 2009).
Pollen analyses from Belderrig suggest pastoral
land-use ending at around 3425 cal BC (Verrill and
Tipping 2010), but pollen analyses from around
the Céide Fields have demonstrated the presence
of cereal-type pollen in a cleared landscape from
the Early Neolithic, between ca. 3800–3250 cal BC
(O’Connell and Molloy 2001). The extent of the field
systems suggests that agriculture took place on a
large scale in this region. It has been suggested that
the land was used largely for pasture and to a lesser
2016 Journal of the North Atlantic No. 30:1–32
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Figure 1. Location of the study area, sites, and test pits.
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degree for arable cultivation (Caulfield 1983). Caulfield’s
original argument for pasture was based on
the large size of the fields and the great extent of the
enclosed land, but the later discovery of ard marks
and stone ard shares within the fields demonstrate that
they were also used, at least in part, for arable production
(Byrne 1991, Byrne et al. 2009a). The extent of
the ploughed land is unknown, because open-area
excavation has been limited. Lazy beds (hand dug
ridge and furrow) were found to the west at Belderrig,
although these seem to be later, dating to the Bronze
Age (Caulfield 1978, Herity and Eogan 1977:50).
Our new research aimed to determine how intensively
the Neolithic fields were used. Cultivation
within the fields could have been long term,
or arable plots could have been shifting in order to
fallow the land. Crop production could have been
improved by adding locally available fertilizers
such as domestic waste (including food remains and
hearth ash), organic-rich sediments (such as peat and
seaweed), or animal dung (Bakels 1997). The Céide
Fields, Belderrig, and Rathlackan are all located
by the sea, so seaweed would have been available,
and organic-rich materials such as mud and peat
(also potential fertilizers) occurred in basins in and
around the fields (O’Connell and Molloy 2001).
Domestic waste would have been available if there
were permanent settlements in or around the fields,
and animal manure would have been available if the
fields were used for pasture, as Caulfield (1983) suggests.
Peat development began in this region before
the elm decline at 5840 cal BP, and continued to
expand during the use of the fields, but peat did not
develop within the fields until after they went out
of use around 3250 cal BC (O’Connell and Molloy
2001). This history would suggest that manuring
might have taken place to keep the soil fertile in the
face of acidification and the spread of blanket bog.
The application of different materials would have
made differing contributions to the fertility of the
soil. The key elements necessary for plant growth
are nitrogen, phosphorus, and potassium, and in addition
there are a number of micronutrients that are
required in smaller quantities. The addition of hearth
ash and kitchen waste would have improved the soil
nutrient availability, as hearth ash contains calcium
and potassium (Canti 2003). The addition of ash to
the soil would also have raised the soil pH. Animal
bone and food residues would have added phosphate
and nitrogen to the soil.
Animal dung is a better fertilizer than ash and
kitchen waste, as it contains all 3 of the macronutrients
required by plants, together with calcium, magnesium,
and other micronutrients (Wild 1993:156).
It is particularly rich in nitrogen, which is the key
nutrient required by cereal crops. Organic manures
such as animal dung also improve the soil structure
by encouraging earthworms, which aerate the soil
and enhance soil cohesion. Soil organic matter also
retains water and enhances the availability of plant
nutrients (Brady and Weil 1999:468; Dungait et al.
2008, 2012). The introduction of animal dung as an
agricultural fertilizer therefore represents a considerable
advance in agricultural land management, and
it is an important indicator for the intensification of
arable production and perhaps also for the emergence
of long-lived (as opposed to shifting) fields.
Different stages of agricultural intensification
can be traced back into prehistory, and a review of
prehistoric soils in England and Scotland has suggested
that Neolithic agriculture took place in small
plots which are more like gardens than arable fields
(Guttmann 2005, Guttmann et al. 2005). Macrobotanical
evidence indicates that the same was true
in Continental Europe (Bogaard 2004, 2005). Soils
were fertilized with domestic or kitchen waste in the
British Bronze Age, and although new evidence suggests
that manuring took place as early as the Neolithic
(Bogaard et al. 2013), there is not yet enough
evidence to suggest that animal manures were widely
used in Britain before the Iron Age (Guttmann et
al. 2005). By contrast, animal manures were used in
Switzerland as early as the Neolithic (e.g., Nielsen
et al. 2000), and there are many records of its use in
the Bronze Age in Western Europe (Bakels 1997).
The aims of the project presented here were to
determine the intensity and extent of agricultural
production within the Céide Fields, and to determine
whether the land was used for pasture or arable agriculture.
We tested the hypothesis that the arable soils
in the Neolithic fields may have been fertilized, and
given the extent of enclosed land—which suggests
a large amount of pasture—that they were fertilized
with animal manures. Such a finding would indicate
the area followed an agricultural model closer to that
currently accepted for Continental Europe than to
that which has been presumed to apply to Britain.
Our specific objectives were: (1) To sample areas
thought to have been arable and pasture within
the Neolithic Fields, and to identify added cultural
materials in the soils such as charcoal, charred peat,
animal bone, animal dung, human excrement, and
seaweed; and (2) To compare soils within the Neolithic
field systems with “control” buried soils dating
to the Mesolithic. This comparison would demonstrate
the degree of enhancement in the arable soils.
Geology and soils
The geology of northern County Mayo is largely
made up of metamorphic and sedimentary rocks.
2016 Journal of the North Atlantic No. 30
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Belderrig is located on Dalradian rocks, which are
mainly metamorphosed sedimentary rock (Long et
al. 1992). The Céide Fields are on carboniferous
rocks of the Downpatrick formation, which is a
complicated interbedding of mudstones, siltstones,
alluvial and deltaic sandstones, limestones, and
shales. Moving west to Rathlackan, the geology is
carboniferous sandstone and siltstones of the Mullaghmore
formation. The solid geology is covered
by drift made up of till (boulder clay). The soils in
the region are peat, with areas of podzolic soils and
acid brown earths.
Methods
In order to determine whether the soils were fertilized,
it was necessary to identify material added to
the soil. We used a range of analytical methods including
thin-section micromorphology, macrobotanical
analysis, and measurements of soil phosphates,
soil magnetism, and lipid biomarkers. The point of
using this wide range of methods was to ensure that
there were no false positives, and to enable correlation
between methods, e.g., phosphate data can be
correlated with the lipid biomarkers analysis, which
provides more specific information about the added
material.
In order to determine whether the soils were
used for arable or pasture, we took samples from
the buried soils for analysis of insect remains. This
did not produce results, probably because the soils
were too oxidized. The second method we used for
distinguishing arable and pasture was the analysis
of compound-specific stable isotopes that are linked
with particular amino acids in the soil. The method
was developed by Simpson et al. (1999a, 1997) and
was based on samples from experimental farms in
Northumberland, the Paris Basin in France, and
North Wyke, Devon. Simpson et al.’s work successfully
distinguished manured grassland, unmanured
grassland, and land used for long-term cereal cultivation,
and also demonstrated that the signatures
were still evident in soils from Bronze Age Orkney
(ibid.). For the current project, we aimed to carry on
the research of Simpson et al. by conducting further
control studies at Rothamsted Research (Harpenden,
Hertfordshire). We took samples at Rothamsted
from areas of manured and unmanured arable land,
and manured and unmanured grassland, in order
to ascertain whether the method was replicable,
before trying it out on the Céide Fields. The results
were encouraging but mixed, and will be discussed
after further analysis in a later publication. We had
planned to compare the stable isotope/amino acid
results with the results from insect analysis, but the
lack of surviving insects made this impossible. This
unsuccessful aspect of the project is introduced here
in order to report on the negative evidence, as well
as the positive.
Sampling strategy
Excavations were undertaken at the Céide Fields
(Fig. 1c), Belderrig (Fig. 1b), and Rathlackan (Fig.
1d). We sampled buried soils dating to the Mesolithic
at Belderrig (Test Pit F). In order to identify
potential fertilizing materials, we also sampled a
midden at Belderrig (Test Pit A). The field method
involved digging 1 m x 1 m test pits through the peat
and underlying Neolithic soils and sampling both
the buried soil and the humified peat that overlay it.
The more fibrous peat above the humified layer was
not sampled because it was disturbed or redeposited
during modern peat cutting. We sampled the humified
peat overlying the buried soil for comparison,
to ensure that any geochemical signatures in the
soil were not derived from material leaching down
from above. The buried soils were sampled for soil
micromorphology, with bulk samples taken for geochemical,
fecal biomarker, insect, and macrobotanical
analyses.
Soil micromorphology
We conducted thin-section micromorphology
to investigate the nature of the buried mineral soil,
including the amount of biological activity, the soil
structure, and the types and quantities of added
cultural material such as charcoal, charred peat, and
bone fragments. Thin sections of undisturbed soil
were prepared at the Royal Holloway, University of
London, and at the University of Reading, School
of Human and Environmental Sciences. Both labs
used oven drying and epoxy resin, rather than the
standard technique of acetone and crystic resin;
otherwise the techniques followed the standard
practice (MacLeod 2008). The thin sections were
examined at magnifications of 40x to 400x using a
polarizing microscope, and were described using the
International System for soil thin-section description
(Bullock et al. 1985). Light sources included
plane polarized (PPL), cross polarized (XPL) and
oblique incident (OIL). Interpretations were aided
by FitzPatrick (1993) and Courty et al. (1989), and
by comparison to reference materials (including
peat, hearth ash, and animal manures) collected in
Shetland and manufactured as thin sections (Guttmann
2001).
The charcoal abundance in thin section was
quantified in 5 size-classes: <150 μm, 150–250 μm,
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250–500 μm, 500 μm–1 mm and >1 mm. We examined
a total of 100 fields of view for each context
using a Leica DMLP trinocular microscope at 200x
magnification. Laterally contiguous fields of view
were examined in transects across the slide until 100
fields of view had been recorded.
Phosphate
We conducted organic/inorganic phosphate analysis
to identify and quantify added animal manures
and domestic waste. Soil samples were air dried and
sieved at 2 mm, and we took two 1-mg subsamples
from each sample. One subsample was heated in a
furnace at 550 °C for an hour in order to transform
the organic P fraction into inorganic P, after which
both samples were subject to sulphuric acid extraction
following Mikkelsen (1997). The heated subsample
thus provided an estimate of the total phosphate
content of the sample (organic and inorganic),
excluding the phosphorus bound in silicate structures
(ibid.). The unheated subsample provided an
estimate of the inorganic fraction. We subtracted the
value of each unheated subsample from the heated,
total P subsample, the difference being the value for
the organic P content. Colourimetry was carried out
using an ammonium molybdate reagent (ibid.)
Fecal biomarker lipids
Feces-derived lipids provide another suite of indicators
for manuring. The 5b-stanols are acknowledged
biomarkers of fecal input, and have been used
in both archaeological and pedological research
(Bethell et al. 1994; Bull et al. 1999a, 1999b, 2002;
Leeming et al. 1996; Simpson et al. 1998, 1999b).
We extracted and analyzed the lipid biomarkers
5b-stanols using the method described by Bull et al.
(1999b). Samples from all sites were processed, but
not from all test pits. We made a selection based on
the likelihood that the sample would be free from
contamination, and ensured that each assumed land
use was represented (pasture, arable, and control).
Following the discovery of high phosphate in the
peat overlying the buried soils, we processed additional
samples from the peat.
Loss on ignition
We used loss on ignition (LOI) to distinguish
soils with added organic matter from soils without
such amendment, based on comparison with
unamended local buried control soils dating to the
Mesolithic. LOI was determined as percentage mass
loss following ignition of oven-dried soil (105 °C)
at 425 °C for 8 hours. We conducted LOI in the first
season only because later peat infiltration into the
samples rendered the analysis meaningless.
Macrobotany
We took 10-litre soil samples for charred macrobotanical
remains from the buried soils in each
test pit. The density of rootlets made sieving and
analysis rather difficult. We scanned the 1-mm sieving
fraction of all the samples using an illuminated
magnifying glass, and selected 8 samples for further
investigation under the microscope.
Soil magnetism
We analyzed soil magnetism (mass susceptibility,
Xfd, ARM, IRM) in order to identify fuel ash
residues in the soil (e.g., Peters et al. 2001). This
method was not successful in distinguishing the
different areas, probably because of the high degree
of iron translocation in the soil, and the results will
therefore not be discussed here. We examined soil
magnetism in the first season only, and not in the
second.
Results
Dating
The field walls have been firmly dated to the
Neolithic (Caulfield et al. 1998), but 2 phases of
activity were identified at Belderrig Beg (Fig. 1b),
where a roundhouse and lazy beds were found (Caulfield
1978). Radiocarbon dates placed the later phase
in the Bronze Age and the earlier in the Neolithic
(ibid.). For the current research, we placed test pits
in a Neolithic/Bronze Age midden (Test pit A) and
in an area where the Bronze Age lazy beds were
discovered (Test pit B). The aim of Test pit A was
to identify the potential fertilizing material within
the midden, and Test Pit B was placed to sample and
compare the soil from the Bronze Age lazy beds and
the underlying Neolithic soil. The lazy beds were
not found, but a radiocarbon date from a charcoal
fragment in the buried soil in Test Pit B confirmed a
Bronze Age Date (Table 1).
Field observations and background
The peat in County Mayo reaches depths of over
4 m, so samples were taken predominantly from
areas where some of the peat had been extracted.
Table 1. Radiocarbon dates (calibrated at 95.4% probability).
Test Date uncal. BP Date
Lab code pit Material (BP = 1950) (cal. BC)
OxA-15270 A Calluna vulgaris 3563 ± 30 1920 ± 60
OxA-15271 A Salix 3649 ± 30 2035 ± 105
OxA-15272 B Ilex aquifolium 3091 ± 29 1360 + 70
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During peat extraction, the more fibrous and poorly
humified upper “topsod” is removed and set aside
(S. Caulfield, University College Dublin, Dublin,
Ireland, pers. comm.), and the black, humified peat
below is removed in long, thin blocks, to be then
dried and used for fuel. As peat cutting progresses,
the topsod is thrown back onto the truncated humified
peat layer, creating what is often a sharp
boundary between redeposited brown topsod and
the truncated black peat that seals the buried soils
(Fig. 2a). The sequence is not always simple; in
places the buried soil was sealed by bands of brown
and black peat, which may represent burning or
peat cutting on more than one occasion (Fig. 2c).
The layer of humified peat overlying the buried
soils was between 1.10 m and just 10 mm thick,
and in one instance (Test Pit C) the peat appeared
to have been extracted right down to the level of the
mineral soil (Fig. 2b).
The buried soils in the field were variable in
color and texture (Appendix 1), ranging from
10YR2/1 (black) to 5/4 (yellowish brown), and
the stone walls of the Neolithic fields often rested
on buried soil horizons that were pale and leached
(e.g., 10YR 5/4). The buried soils were 40–190 mm
thick, and in a few instances there was evidence
of soil profile development, with slightly paler,
leached eluvial horizons below the buried topsoil.
The thin depth of the buried soils suggests that
they have been either truncated or eroded. Test Pit
J (Fig. 3a) shows the development of soil horizons,
consisting of a layer of black peat (126) over a thin,
pale brown horizon with an indeterminate boundary
onto a grey horizon. The brown/grey horizon (127)
had characteristics of a buried soil, e.g., dense and
very dense excremental fabric and a moderate porosity.
Below this was a distinctly leached eluvial
horizon that overlay gleyed till.
We had hoped to find traces of the lazy beds described
by Caulfield et al. (2009) at Belderg Beg, but
Test Pit B did not contain any obvious cultivation
ridges or furrows. Possible cultivation ridges were
found in Test Pit 3 in the Céide Fields, however,
where there was a 4-cm-high ridge adjoining a 4-cmdeep
furrow at the interface between
the base of the buried soil and the surface
of the till below. The buried soils
in Test Pit 10 at Rathlackan were contained
entirely within a furrow, reaching
a depth of 10 cm and tapering to 0
cm over a length of 50 cm. Shallower
and less convincing wavy interfaces
occurred in Test Pit J (Céide Fields)
and Test Pits 7 and 8 at Rathlackan
(Fig. 4a).
On slopes, the field walls act as sub-peat drains,
with water-lain silts and sands accumulating in
lenses between and around the stones; this was a
phenomenon that was also noted in excavation at
Belderrig by Warren (2004). The passage of rainwater
down through the soil profile has also affected the
soil; iron panning was evident in some of the buried
B horizons and also in the stony, compacted, and
often gleyed glacial till below.
Micromorphology, LOI, and macrobotanical
evidence
There was a vast amount of variation in the soil
organic matter of the samples, and many of the horizons
identified as mineral soils in the field were
actually higher in organic matter than the layers
identified as well-humified peat, based on loss-onignition
results (Table 2; see also Supplementary
Table 1, available online at http://www.eaglehill.
us/JONAonline/supl-files/J091812-Guttman-Bonds1,
and for BioOne subscribers, at http://dx.doi.
org/10.1656/J091812.s1). The thin-section analysis
(Appendix 2) provides an explanation for these unexpected
findings: the buried soils contain frequent
rootlets in a state of partial decay, making them
more organic-rich (Fig. 3b, c), and the black peat
layers often contained charcoal, suggesting that
some of the organic matter within them had already
been burned. Regular burning of moorland prevents
heather from growing too large and woody; it is possible
that the fires were intentional, but natural fires
in this region date back to the Mesolithic (Molloy
and O’Connell 1995).
Many of the buried soil samples contained
15–20% organic material, as estimated in thin section.
Conversely, the peat horizons contained up to
20–30% mineral material (silt and sand size), which
suggests that either the peat was redeposited, or that
sediment washed over or blew into these horizons
and accumulated within them during their formation.
It is also possible that the peat and soil were
mixed due to cultivation; the soils in Test Pits 5 and
6 at Rathlackan—both within the same enclosure—
Table 2. Phosphate and loss on ignition (LOI) ranges given in mg per 100 g.
Location Total P Organic P % LOI
Buried soils, Rathlackan 9.03–44.80 8.59–33.81 -
Buried soils, Céide Fields 6.45–76.12 8.20–74.58 5.48–90.54
Peat (Céide Fields) 28.25–88.24 24.05–86.62 7.24–11.45
Buried soils, Belderrig 10.60–33.88 10.46–29.29 9.09–31.70
Peat (Belderrig) 16.08 16.03 95.56
Buried soil, control Mesolithic 11.14–13.46 7.14–9.43 13.79–81.96
Till 13.68–34.06 9.43–33.48 12.68–89.08
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Figure 2. (a)
Soil profile,
Test Pit B
( B e l d e r r i g )
photo and section
drawing;
(b) Test pit C
( B e l d e r r i g )
photo; (c) Test
pit G (Belderrig)
photo.
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organic material with intact sheets of phytoliths.
Rathlackan’s Test Pits 7 and 12 also contained peat
fragments in the buried soils (205) and (217). Field
observations support the notion that the peat layer
contained peat fragments similar to those found
in plaggen soils (cf. Guttmann et al. 2006). These
layers (contexts 202 and 200) included porous to
dense excremental fabric, and 202 also contained
Figure 3. (a) Test pit J (Céide Fields) photo and section drawing; (b) Rootlets in the buried soil, macro (Céide Fields Test
Pit I, layer 119); (c) Rootlets in the buried soil, micro (Céide Fields Test Pit I, layer 119).
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The structure of the soils in thin section was
characterized by cracks (due to wetting and drying)
and channels, derived from either earthworm activity
followed by root penetration or from root penetration
alone. The channels were typically around
1 mm wide and had a vertical to 45° orientation.
The remains of roots were evident within the channels,
which carry on down into the till (hence the
high LOI of many of the till samples). The organic
root material within the channels was often well
preserved or only slightly decayed. The porosity of
the samples was typically 20–30%, with much of the
void space occurring as channels in which rootlets
were partially decayed.
A number of the samples were characterized by a
platy structure of planar voids and flattened organic
aggregates, a sign of compaction that is frequently
interpreted as an indication of ploughing (Macphail et
al. 1990). However, this was more often a characteristic
of peat layers, occurring in a soil only in test pit
18 in the Céide Fields, in which soil (243) contained
horizontal lenses of peat. In several layers, we noted
that the channels cut through the horizontal peat layers,
indicating that the rootlet penetration occurred at
a later date. Test Pit 4 in the Céide
Fields contained horizontal laminations
in the peat and clay domains
occurring in the soil fabric; the clay
domains might be interpreted as
fragmented plough pan.
Soils develop through processes
of chemical and physical
weathering, and are generally distinguished
from sediments by the
presence of soil horizons (French
2003:35). On a microscopic scale,
soil formation can be identified by
the presence of “pedofeatures”,
or soil-forming features (French
2003:40). Pedofeatures are characteristics
that derive from physical
and chemical weathering processes
such as leaching and oxidation, and
also from the biological activities
of soil biota such as earthworms
and mites. There was abundant evidence
for oxidation and reduction
in the samples, in the form of iron
accumulation around the rootlets
and the channels in which they occurred.
This evidence for redox processes
is indicative of wetting and
drying, which is hardly surprising
in a temperate landscape covered
in blanket bog. Evidence for transwas
disturbed and possibly ploughed: Test Pit 7 had
a wavy interface between the buried soil (205) and
the subsoil below (206), as well as at the base of the
subsoil (Fig. 4a). Test Pit 12 showed an irregularity
in the interface between the humic black peat (216)
and the buried soil below (217); this finding could
be due to either prehistoric arable activity or modern
peat cutting (Fig. 4b).
Phytoliths occurred in both the peats and soils;
phytoliths are concentrated in animal dung, but they
also occur naturally in soil and peat. A more unusual
occurrence was the occasional cluster of spherulites,
which are an indicator of animal manure (Canti
1997), but it is difficult to believe that these calcitic
structures could survive in such an acidic environment,
and it is possible that they are an artifact of
thin-section processing. A more convincing indicator
for manuring was found in the form of a bright
blue mineral (PPL and XPL) interpreted as vivianite
in the buried soil (226) in the Céide Field Test Pit 3.
Vivianite is a phosphatic mineral which occurs naturally
in wet, peaty soils (Bullock et al. 1985:72) but
it is also associated with human and animal excrement
(Mcgowan and Prangell 2006).
Figure 4. (a) Test pit 7 (Rathlackan) section drawing; (b) Test pit 12 (Rathlackan)
section drawing.
2016 Journal of the North Atlantic No. 30
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10
soil quality, attracting earthworms, and increasing
agricultural yields.
A size analysis on the charcoal fragments in thin
sections from all sites indicated that 96.3% of the
fragments were in the size class of less than 150 μm (Fig.
5; see also Supplementary Table 2, available online
at http://www.eaglehill.us/JONAonline/supl-files/
J091812-Guttman-Bond-s1, and for BioOne subscribers,
at http://dx.doi.org/10.1656/J091812.s2).
Since this is the size class most likely to be carried
by the wind (Clark 1988), it cannot be conclusively
stated that the land was intentionally fertilized with
hearth ash. Larger fragments were found in small
quantities in other contexts, particularly the Belderrig
midden, but only 21 fragments over 500 μm were
recorded in thin section. Some of the charcoal noted
in thin section was from burned peat, identified by
its structure and the inclusions of mineral grains
(Davidson and Carter 1998).
Molloy and O’Connell (1995) noted that the
black, humified peat layer in the Céide Fields area
contained frequent charcoal, which was interpreted
as a consequence of burning on the peat surface. The
charcoal dates predominantly to before the Neolithic
land clearance, with the latest major deposition occurring
200 years before the clearance phase (ibid.).
Burning as part of the clearance phase is suggested
by Caulfield (1978), who noted that charcoal occurs
in all the exposures of the buried mineral soil within
the field systems. Given the ubiquity of charcoal in
the landscape before and possibly during the use of
the field system, it is impossible to ascribe either
natural or human causes to the burning, apart from
the evidence within the clearly archaeological midden
deposits at Belderrig.
All macrobotanical samples contained small- to
moderate-sized charcoal measuring less than 6 mm.
Most contained un-diagnostic spores, many of which
seemed to have been charred. There were no charred
seed remains in any of the samples investigated,
but small lumps of humified peat were found in the
bulk sieving from the buried soil in Test Pit G, and
burnt peat was recovered from the Belderrig midden
(Table 3). We identified charcoal from the Belderrig
location of clays and silt was very rare; there were
very rare mineral grains with birefringent coatings,
but (apart from in Test Pit 1 in the Céide Fields) the
soil voids did not have either the limpid clay coatings
that might be expected from a woodland soil,
or the dusty clay coatings which would indicate
disturbance such as that brought about by cultivation
(Jongerius 1983, Macphail et al. 1987).
Another important pedofeature that is useful in
this context is excremental fabric, which is an indicator
for the presence of soil biota. This fabric includes
rounded aggregates of excrement in differing
states of decay. When the aggregates are still distinct
and rounded, the fabric is described as porous and
very porous, and is an indication of recent biological
activity (Bullock et al. 1985:137). Over time, the
aggregates coalesce into dense and very dense
excremental fabric. Nineteen soils (including soils
from all 3 sites) contained rare to very rare porous
excremental fabric, indicating potentially recent
earthworm or mesofaunal activity (e.g., collembola,
mites). The porous excremental fabric was confined
almost entirely to the channels, in which organic
material was partially decayed. Twenty-seven soils
(from all 3 sites) contained dense and very dense
excremental fabric, indicating both age and compaction
of the soils (ibid.) and that the soils were once
biologically active.
Potentially anthropogenic material visible in the
soil thin sections was limited to charcoal and charred
peat fragments. Soil charcoal is traditionally interpreted
as the result of burning of the vegetation for
land clearance prior to agriculture, but hearth ash is
also applied as fertilizer in regions where the soil
is naturally acidic (Guttmann et al. 2005). Ash is
calcareous and helps to raise the soil pH, improving
Figure 5. Charcoal distribution by fragment size range,
based on contiguous transects of the thin section slides.
Table 3. Macrobotanical remains.
Sample Test pit Site Results
1 C Belderrig
4 D Belderrig 2 fragments possible charred
pine bracts
9 1050/990 Belderrig
10 A (midden) Belderrig
13 B Belderrig Burnt peat
14 A (midden) Belderrig
15 A (midden) Belderrig
27 G Ceide Small lumps of humified peat
Journal of the North Atlantic
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E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
The main taphonomic problem with organic/
inorganic phosphate analysis is that soil microbes
convert organic P into inorganic P in aerobic conditions,
but (as predicted) the waterlogging and acidity
has prevented this from taking place. The samples
contained predominantly organic P and very little
mineralized P, which suggests that the inputs were
organic material such as manures. The total P plot
shows a similar distribution to the organic P (Fig.
6b). The outlier in Figure 6b showing higher total P
levels is from the Céide Fields Test Pit 3, in the field
to the south of the field containing ard marks.
If the sites are presented individually, the P distribution
from the Céide Fields appears similar to the
overall distribution (Fig. 7a), but a slightly different
pattern is apparent at Belderrig, where P seems to
have leached down into the till to a greater degree
(Fig. 7b). The P levels in the Belderrig peat are lower
than on the other sites.
Samples were taken from 2 fields and 2 enclosures
at Rathlackan (Test Pits 5–12, 29, and 30; Fig. 1d). The
total P distribution showed a high level of P in Test Pits
7 and 8 compared to the controls, with slightly raised
levels also occurring in the field immediately to the
south (Fig. 8). The 2 enclosures, by contrast, contained
P at about the same levels as the controls.
Fecal biomarker lipids
The stanol index ([5β-stanol + epi-5β-stanol]:[5α-
stanol + 5β-stanol + epi-5β-stanol]) (Simpson et al.
midden as Calluna vulgaris, another indicator that
peat was burnt on this site.
Phosphate
The phosphate results indicated raised levels of
P in the buried soils as compared to the controls,
which suggests low levels of anthropogenic inputs
in the buried soils (Table 2; see also Supplementary
Table 1, available online at http://www.eaglehill.
us/JONAonline/supl-files/J091812-Guttman-Bonds1,
and for BioOne subscribers, at http://dx.doi.
org/10.1656/J091812.s1, and Supplementary Table
3, available online at http://www.eaglehill.us/
JONAonline/supl-files/J091812-Guttman-Bonds3,
and for BioOne subscribers, at http://dx.doi.
org/10.1656/J091812.s3). The peat from the 3 sites
was also significantly richer in phosphate than the
control samples (P = 0.000), based on an ANOVA in
SPSS using replicate samples from each site. Figure
6a shows that the highest levels of organic phosphate
were actually derived from the peat, which is probably
the result of several processes, to be discussed
below. The outliers shown in Figure 6a indicate
particularly high organic phosphate in contexts 121
(the buried soil in Test Pit G) and 226 (the buried
soil in Test Pit 3; note that vivianite also occurred
in this context). Test Pit G was in the field in which
the ard marks and ard share were found in the 1991
excavation (Byrne et al. 2009b), and Test Pit 3 was
in the field immediately to the south.
Table 4. Concentrations (μg g-1 soil) of bile acids extracted from buried soils. LC = lithocholic acid, DOC = deoxycholic acid, CDOC =
chenodeoxycholic acid, HDOC = hyodeoxychoilic acid, UDOC = ursodeoxycholic acid, and X = 3a-hydroxy-12-oxo-5b-cholanic acid. All
acids given in μg g-1 soil.
Sample/
context Site Test pit Type LC DOC CDOC HDOC UDOC X
10/108 Belderrig A Buried soil 0.00 0.41 0.00 0.27 0.00 0.00
07/104 Belderrig D Buried soil 0.00 0.36 0.00 0.00 0.00 0.00
13/110 Belderrig B Buried soil 0.00 0.94 0.00 0.00 0.00 0.00
47/129 Ceide H Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
43/127 Ceide J Buried soil 0.47 0.95 0.05 0.06 0.00 0.19
27/121 Ceide G Buried soil 0.00 2.06 0.00 0.00 0.00 0.00
42/125 Ceide G Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
30/119 Ceide I Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
49/238 Ceide 27 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
24/222 Ceide 1 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
73/243 Ceide 18 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
33/117 Ceide I Peat 0.00 0.37 0.00 0.00 0.00 0.00
13/211 Rathlacken 9 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
09/208 Rathlacken 8 Buried soil 0.00 0.09 0.00 0.00 0.00 0.00
15/213 Rathlacken 11 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
05/205 Rathlacken 7 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
03/203 Rathlacken 5 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
07/206 Rathlacken 7 Buried sub-soil 0.00 0.00 0.00 0.00 0.00 0.00
11/209 Rathlacken 8 Buried sub-soil 0.00 0.00 0.00 0.00 0.00 0.00
44/234 Area E 24 Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
60/136 Control F Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
61/136 Control F Buried soil 0.00 0.00 0.00 0.00 0.00 0.00
63/136 Control F Buried soil 0.00 0.5 0.00 0.00 0.00 0.00
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
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Figure 6. (a) Distribution of organic P in the Céide Fields, Belderrig, Rathlackan, Area E and the controls; (b) Distribution
of total P in all sites. The boxplots show the maximum and minimum values for each sample set, with the median line in
the center.
Journal of the North Atlantic
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E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Figure 7. Organic P in (a) Céide Fields and control soils, and (b) in Belderrig and control soils. The boxplots show the
maximum and minimum values for each sample set, with the median line in the center.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
14
1998; Bull et al. 1999b, 2002), summarized as [5β:5α
+ 5β], was used to detect the ancient deposition of
manures in archaeological soils at Céide, Rathlackan,
and Belderrig (Table 4). All of the buried soils analyzed
contained 5b-stanols, which suggests the presence
of herbivore feces, but which could also be natural
background levels. The undisturbed Mesolithic
control soils contained a significantly higher stanols
index [5β:5α + 5β] compared with Rathlackan,
Belderrig, and Céide (Fig. 9), which indicates that
the 5b-stanols are probably natural and do not suggest
manuring. The single samples analyzed from
the overlying peat at Céide and the buried soil from
Area E provided ratios of (5β:5α + 5β) = 0.11 and
0.07, respectively, and (5β:5α + 5β) = 0.25 ± 0.11 for
the buried sub-soil from Rathlackan, but these were
less than or similar to the control soils ([5β:5α + 5β] =
0.29 ± 0.01). The 5b-stanols and total phosphate were
correlated to test whether enhanced levels of organic
phosphate were reflecting added organic manures
(Linderholm 1997), but the results showed no statistically
significant relationship (P = -0.24).
The analysis of bile acids produced some interesting
but widely variable results. Overall, deoxycholic
acid was the most common bile acid (Table 4).
In isolation, deoxycholic acid provides evidence of
bovine dung, and in combination with lithocholic
acid it is evidence for human feces (Simpson et al
1999b). All of the soils that contained deoxycholic
acid also contained 5b-stanols (but not vice versa).
Deoxycholic acid occurred in 1 of the 3 control soils
at 0.50 mg g-1 soil; it was 0.00 mg g-1 soil in the other
two. Deoxycholic acid was identified in all Belderrig
buried soil samples (Test Pit A: 0.41mg g-1 soil,
Test Pit B: 0.94 mg g-1 soil, and Test Pit D: 0.36 mg
g-1 soil). Test Pit B, with the slightly raised level, was
the buried soil sample taken from a buried Bronze
Age soil. Deoxycholic acid also occurred in 1 of 5
Rathlackan samples (0.19 mg g-1 soil), and also in a
peat sample from Céide Test Pit I (0.37 mg g-1 soil).
The buried sub-soil samples from Rathlackan and
the buried soil from Area E contained no evidence of
deoxycholic acid. Two of the 8 buried soil samples
from Céide contained deoxycholic acid, but in
Figure 8. Total P in Rathlackan fields and enclosures. The boxplots show the maximum and minimum values for each
sample set, with the median line in the center
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E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
significantly different concentrations: 0.95 mg g-1
(Test Pit J) and 2.06 mg g-1 in Test Pit G. Hyodeoxycholic
acid was also identified in 1 of the Belderrig
buried soils and in 1 of the Céide soils. In the latter
sample, deoxycholic acid and hyodeoxycholic acid
were identified along with lithocholic acid, chenodexoycholic
acid, and 3a-hydroxy-12-oxo-5b-cholanic
acid.
Discussion
In 1991, a cluster of ard marks and a stone ard
share were uncovered in the Céide Fields in an area
that is now beneath the Visitor Center (Byrne et al.
2009b). In 2004–2005, we placed 4 test pits to the
east of the Visitor Center, in the same Neolithic
field as the ard marks and ard share, and a further
3 test pits in the field immediately to the south. The
evidence from these test pits suggests that the arable
area extended to the south and east of the Visitor
Center. The soil in Test pit 18 (ard mark field) contained
planar voids with horizontal lenses of peat.
The soil in Test Pits 3 (to the south of the ard mark
field) and Test Pit G (the ard mark field) had organic
phosphate levels that were significantly higher than
the other soil samples, such that they appear as outliers
in the organic P plot for all 3 sites. The highest
level of deoxycholic acid on the site (2.06 μg g-1)
was found in Test Pit G. Test Pit G also had small
lumps of humified peat in the buried soil, which
may indicate mechanical mixing such as would take
place in an arable ploughsoil. Taken together, these
indicators suggest that the entire field may have been
used as arable land, and that it is likely to have been
manured with bovine dung.
The Neolithic field to the south of the ard mark
field also contained potential arable indicators. The
buried soil in Test Pit 1, located within a round enclosure
to the south of the 1989 excavation trenches,
contained the only dusty clay coatings noted in the
excavation; these coatings are an indicator of disturbance
usually associated with ploughing (Macphail
et al. 1987), although they can also arise from other
types of disturbance (Wilson 2000). Test Pit 2 was
abandoned due to the truncation of the shallow soil,
but the buried soil in Test Pit 3 contained an outlier
with the highest total P found on all 3 sites. The
buried soil in Test Pit 3 had a distinctively wavy
interface with the till below, suggesting cultivation;
this soil also had the highest organic P concentration
found on the 3 sites, as well as vivianite, a phosphatic
mineral associated with manuring. Test Pit
Figure 9. Mean (5β:5α + 5β) for buried soils from Belderrig (n = 3), Rathlackan (n = 5), Céide Fields (n = 8), and control
areas (n = 3). The boxplots show the maximum and minimum values for each sample set, with the median line in the center.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
16
4 contained a possible re-worked plough pan in the
form of disturbed clay domains (cf. Gebhardt 1992,
Lewis 1998).
Rathlackan had one field that was distinctly
higher in P than the controls. Test Pits 7 and 8, within
this field, not only had higher total P but also had
evidence for possible ploughing or cultivation ridge
and furrow. Test Pit 11, within the southern enclosure,
also had a slightly wavy boundary between
the base of the buried soil and the top of the natural
till. Test Pits 10 and 11 had raised P compared to
the enclosures, but it was not as pronounced as the
distinctly higher levels in the northern field.
The phosphate sampling showed generally higher
levels of P in the peat than in the buried mineral
soils, although natural blanket peat is not naturally
high in P (Grime and Guttmann-Bond 2011, Renou
and Farrell 2005). Phosphorus gains derive from
P that is sorbed on wind-blown dust particles, but
this usually contributes very low levels of P to the
developing peat (Brady and Weil 1999:551). The P
enrichment of the peat in the Neolithic field systems
is likely to derive partly from such aeolian deposits,
but the high levels have most likely been brought
up from the Neolithic mineral soils via plant roots.
As plants decay on the peat surface, the P returns
to the developing peat, and probably continued to
be drawn up to the upper peat levels as the peat
accreted. Water throughput in blanket peat is extremely
slow, with movement of less than 1 cm per
day (Renou and Farrell 2005); this water may have
brought low levels of P from upslope, which in all
cases consists of blanket bog. Erosion from the Penriched
Neolithic arable soils may also be a factor;
the soils contained mineral grains which might have
eroded into the peat via wind or sheetwash.
The thin-section analysis identified high quantities
of sand and silt within the peat, interpreted as a
result of erosion of the local soils via wind or sheetwash.
Molloy and O’Connell (1995) also observed
large quantities of mineral material in the peat when
they undertook pollen analyses in the region, and
they also concluded that the material represents erosion
of local soils. This is a hilly region, and colluviation
could have been accelerated by either arable
agriculture or overgrazing. Occasional bog bursts
also occur in this area during heavy rainfall.
Peat fragments also indicate mechanical mixing,
possibly due to recent peat cutting but possibly also
due to prehistoric cultivation. Both interpretations
would explain the shallow depth of the buried soils
identified in the field, but the evidence for mineral
grains in thin section ties in with the work of Molloy
and O’Connell (1995), who noted the presence
of sediment in the peat and also frequent charcoal,
indicative of burning on the peat surface. The charcoal
deposition and erosion events that they identified
took place before the Neolithic clearance for the
Céide Fields (ibid.). The evidence from the current
study suggests that soil erosion—possibly accelerated
by ploughing or grazing animals—continued
to take place while the Céide Fields were in use and
may have continued after the fields were abandoned.
The burnt peat and Calluna vulgaris charcoal
from the Neolithic/Bronze Age midden deposit at
Belderrig, together with the occasional charred peat
seen in thin section, suggests that peat was used as
a fuel and may also have been used as fertilizer on
the fields. Charred peat was identified in Test Pits
A and B at Belderrig; Area E; Céide Fields Test Pits
G, I, 1, 18, 19, 21, and 26; and Rathlackan Test Pit 8.
Charred peat was also seen in thin section in the peat
layer of Test Pits E, G, I, J, 19, 20, 21, and 26. The occurrence
of charred peat fragments in the peat could
be due to natural fires or to mixing—which suggests
that the charred peat in the buried soils could also be
natural. It is difficult to draw conclusive evidence
from this indicator alone, but it may be significant
that the one sample containing charred peat at
Rathlackan was from a test pit with raised levels of
phosphate in the field thought to be arable land.
The phosphate within the peat is likely to derive
from the soil of the fields, and the low levels of
P in the buried soils suggests that they have been
depleted, either through truncation, removal of P
by plants, or both. The enhanced organic P, together
with the bile acid data, suggests that there was some
amendment with animal manures. The presence of
charcoal in the buried mineral soils suggests that
fires continued to occur in the landscape, but there
is no evidence to conclusively argue that charcoal
was intentionally spread onto the land as fertilizer,
or to distinguish whether the burning episodes were
natural or intentional.
The lipid results were mixed. Although 5bstanols
were observed in most of the buried soil
samples from Belderrig, Céide, and Rathlackan,
these alone did not provide sufficient evidence to
support the managed application of animal manures
in the Neolithic. There is a natural background of
5b-stanols in the environment (Bethel et al. 1994),
and, since the chemical precursors of the fecal biomarker
sterols and 5a-stanols occur naturally in the
environment, there exists the possibility for the diagnostic
ratio of (5β:5α + 5β) proxy to be obscured by
the latter addition of the 5a component, be it directly
or as a reduction product of its precursor. Downward
transport of these components from overlying peat
may explain why there was no definitive signal of
fecal input using these biomarkers.
Journal of the North Atlantic
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Bile acids are more specific indicators for fecal
material as they derive from mammalian metabolism
rather than as a reductive product of a dietary compound,
i.e., stanols, and have been shown to be more
stable in the environment than stanols (Elhmmali et
al. 1997). The results of the analysis of the 2 compound
classes described support this specificity;
although all but 1 of the samples analyzed contained
5β-stigmastanol and/or its epimer, only 8 contained
bile acids. Therefore, instances where deoxycholic
acid was the dominant bile acid, and coincident
with 5b-stanols, can be tentatively ascribed to cattle
dung. The presence of cattle dung suggests that herbivore
dung was added to the soil—although it may
have simply been the unstructured deposition of fecal
material by grazing animals. The highest level of
deoxycholic acid on the site (2.06 μg g-1) was found
in Test Pit G, which was on or near the area of ard
marks. Possible manuring also occurred in the buried
Bronze Age soil at Belderrig, in the area where
cultivation ridges were recorded in the excavation of
1971–1982 (Byrne et al. 2009). However, because
most of the samples produced levels comparable to
the control soils (0 to 0.5 μg g-1), the results of this
analysis did not strongly support the hypothesis of
manuring of the Céide Fields, apart from in Test
Pit G.
One buried soil sample from the Céide Fields
contained a wider range of bile acids than the other
samples. Test Pit J, placed in a field thought to be for
pasture, contained a significant quantity of lithocholic
acid. Although no coprostanol was observed, this
indicator suggests the input of human fecal material.
Human excrement has certainly been used as fertilizer
in many parts of the world, and if composted can be
quite safe (De Bertoldi et al. 1983, Poincelot 1972),
but without more replicate samples it cannot be demonstrated
that this “fertilization” was intentional.
Agricultural fields play a prominent part in landscape
development in the Early Neolithic in Ireland,
but for reasons we cannot explain, they apparently
fell out of use in the Late Neolithic. This agricultural
decline is supported by pollen analysis (O’Connell
and Molloy 2001, Verrill and Tipping 2010) and by
a radiocarbon dating program of charred Neolithic
cereal grains, the majority of which date from ca.
3800–3000 (Brown 2007). It may be that large field
systems were replaced by small plots of land which
were more like gardens than fields—a form of agriculture
that we see in the Neolithic in Scotland
(Guttmann 2005) and on the Continent (Bogaard
2005). This study has demonstrated that early Neolithic
agriculture in Ireland seems to follow the
Continental model, in which animal manures were
used as fertilizer in the Neolithic. This may in fact
turn out to become the new model for Neolithic agriculture
in Britain as well, given the new findings by
Bogaard et al. (2013). This is an exciting new area
of research, which we shall be following closely.
Conclusions
The hypothesis for this project was that the land
within the enclosed Neolithic fields may have been
manured or fertilized, given that 1) ard marks and
cereal pollen indicate that some of the land was
cultivated, 2) fertilizing material would have been
available, and 3) the land was enclosed, which suggests
an intensity of land use. The actual site of the
ard marks now sits underneath a building, so we
could not obtain a set of samples from a soil that
was unambiguously arable, but buried soils from the
test pits within the same Neolithic field produced
high phosphates and the highest levels of deoxycholic
acid found on all 3 sites, which suggests the
presence of animal manure in the soil in this area.
Micromorphology also suggested possible ploughing
in this field, as did the presence of small lumps
of peat mixed into the buried soil. The field to the
south of this one also had evidence for soil amendment
and ploughing, including dusty clay coatings,
a possible plough pan, and the highest P from any of
the test pits.
The conclusion is that the early Neolithic Céide
Fields, Belderrig, and Rathlackan were used for both
arable and pastoral farming, and that herbivore dung
was added to the soil of 2 fields at Céide and possibly
also 1 at Rathlackan. We also have tentative
evidence for the presence of bovine manure in the
Bronze Age soil at Belderrig, together with burning
of peat for fuel. Caulfield (1978) suggested that land
use at Belderrig may have actually prevented the
peat from spreading into the fields, and the evidence
from this study supports this idea.
Acknowledgments
This project was funded by grants from NERC, the British
Academy, and The University of Reading. Many thanks
go to Prof. Seamas Caulfield, who showed E. Guttmann-
Bond around the fields and Belderrig, but did not wish to
be included in the publication, and also to Gretta Byrne,
who showed E. Guttmann-Bond around Rathlackan. Both
colleagues were of great assistance to the project. We are
grateful to Mick Monk, University College Cork, for looking
at the flots for potential Macrobotanical remains, and to
Paul Stevens, who held the archaeological license for the
projects. Special thanks to E. Guttmann-Bond’s students,
Antonia Morgan-Forster, Lynne Roy, and Jen Gilpin.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
18
Literature Cited
Bakels, C.C. 1997. The beginnings of manuring in western
Europe. Antiquity 71:442–445.
Barclay, G.J. 1997. The Neolithic. Pp.127–149, In K.J.
Edwards and I.B.M. Ralston (Eds.). Scotland: Environment
and Archaeology, 8000 BC– AD 1000. John
Wiley and Sons, Chichester, UK.
Barker, G. 1985. Prehistoric Farming in Europe. Cambridge
University Press, Cambridge, UK.
Bethell, P.H., L.J. Goad, R.P. Evershed, and J. Ottaway.
1994. The study of molecular markers of human activity:
The use of coprostanol as an indicator of human
faecal material. Journal of Archaeological Science
21:619–632.
Bogaard, A. 2004. Neolithic Farming in Central Europe:
An Archaeobotanical Study of Crop Husbandry Practices.
Routledge, London, UK.
Bogaard, A. 2005. “Garden agriculture” and the nature
of early farming in Europe and the Near East. World
Archaeology 37(2):177–196.
Bogaard, A., R.A. Fraser, T.H.E. Heaton, M. Wallace,
P., Vaiglova, M. Charles, G. Jones, R.P. Evershed,
A.K. Styring, N.H. Andersen, R.-M. Arbogast, L.
Bartosiewicz, A. Gardeisen, M. Kanstrup, U. Maier,
E. Marinova, L. Ninov, M. Schäfer, and E. Stephan.
2013. Crop manuring and intensive land management
by Europe’s first farmers. Proceedings of the National
Academy of Sciences 110(31):12,589–12,594.
Bradley, R. 2003. Neolithic expectations. Pp.218–222, In
I. Armit, E. Murphy, E. Nelis, and D. Simpson (Eds.).
Neolithic Settlement in Ireland and Western Britain.
Oxbow Books, Oxford, UK.
Brady, N.C., and R.R. Weil. 1999. The Nature and Properties
of Soils. Prentice-Hall International, London, UK.
Brown, A. 2007. Dating the onset of cereal cultivation in
Britain and Ireland: The evidence from charred cereal
grains. Antiquity 81:1042–1052.
Bull, I.D., I.A. Simpson, P.F. van Bergen, and R.P. Evershed.
1999a. Muck n’ molecules: Organic geochemical
methods for detecting ancient manuring. Antiquity
73:86–96.
Bull, I.D., I.A. Simpson, S.J. Dockrill, and R.P. Evershed.
1999b. Organic geochemical evidence for the origin
of ancient anthropogenic soil deposits at Tofts Ness,
Sanday, Orkney. Organic Geochemistry 30:535–556.
Bull, I.D., M.J. Lockheart, M.M. Elhmmali, D.J. Roberts,
and R.P. Evershed. 2002. The origin of faeces by
means of biomarker detection. Environment International
27:647–654.
Bullock, P., N. Federoff, A. Jongerius, G. Stoops, and
T. Tursina. 1985. Handbook for Soil Thin Section
Description. Waine Research Publications, Wolverhampton,
UK.
Byrne, G. 1990. Rathlackan: Court tomb with associated
pre-bog settlement. Available online at http://www.
excavations.ie/report/1990/Mayo/0001024/. Accessed
3 March 2016.
Byrne, G. 1991. Céide Fields, Glenulra and Behy, Neolithic
Field System. Available online at http://www.excavations.
ie /report/1991/Mayo/0001157/. Accessed 3
March 2016.
Byrne, G., Downes, M., N. Dunne, G. Warren, S. Rathbone,
D. McIlreavy, and P. Walsh. 2009a. Archaeological excavations
at Belderg Beg (E109): Stratigraphic report.
Unpublished Report. University College Dublin School
of Archaeology, Dublin, Republic of Ireland.
Byrne, G., N. Dunne, S. Caulfield, G. Warren, P. Walsh,
D. McIlreavy, and S. Rathbone. 2009b. Archaeological
excavations in association with the construction of the
Céide Visitor Centre (E494). Stratigraphic Report. Unpublished
Report. University College Dublin School
of Archaeology, Dublin, Republic of Ireland.
Canti, M. 1997. An investigation of microscopic calcareous
spherulites from herbivore dungs. Journal of Archaeological
Science 24:219–231.
Canti, M. 2003. Aspects of the chemical and microscopic
characteristics of plant ashes found in archaeological
soils. Catena 54:339–361.
Case, H. 1969. Neolithic explanations. Antiquity
43:176–186.
Caulfield, S. 1978. Neolithic fields: The Irish evidence.
Pp.137–143, In H.C. Bowen, and P.J. Fowler (Eds.).
Early Land Allotment in the British Isles: A Survey of
Recent Work. British Archaeological Reports (British
Series 48), Oxford, UK.
Caulfield, S. 1983. The Neolithic settlement of north
Connaught. Pp.195–215, In T. Reeves-Smith and F.
Hammond (Eds.). Landscape Archaeology in Ireland.
British Archaeological Reports (British Series 116),
Oxford, UK.
Caulfield, S., R.G. O’Donnell, and P.I. Mitchell. 1998.
14C dating of a Neolithic field system at Céide Fields,
County Mayo, Ireland. Radiocarbon 40(1–2):629–640.
Caulfield, S., G. Byrne, M. Downes, N. Dunne, G. Warren,
S. Rathbone, D. McIlreavy, and P. Walsh. 2009. Archaeological
excavations at Belderg Beg (E109). Unpublished
Report. University College Dublin School
of Archaeology, Dublin, UK.
Clark, J.S. 1988. Particle motion and the theory of charcoal
analysis: Source area, transport, deposition, and
sampling. Quaternary Research 30:67–80.
Cooney, G. 2003. Rooted or routed? Landscapes of Neolithic
settlement in Ireland. Pp.47–55, In I. Armit, E.
Murphy, E. Nelis, and D. Simpson (Eds.). Neolithic
Settlement in Ireland and Western Britain. Oxbow
Books, Oxford, UK.
Courty, M.A., P. Goldberg, and R. Macphail. 1989. Soils
and Micromorphology in Archaeology. Cambridge
University Press, Cambridge, UK.
Davidson, A., and P. Carter. 1998. Micromorphological
evidence of past agricultural practices in cultivated
soils: The impact of a traditional agricultural system
on soils in Papa Stour, Shetland. Journal of Archaeological
Science 25:827–838.
De Bertoldi, M., G. Vallini, and A. Pera. 1983. The biology
of composting: A review. Waste Management and
Research 1(2):157–176.
Dungait, J.A.J., R. Bol, M.J.I. Briones, and R.P. Evershed.
2008. Bulk tissue and fatty acid stable isotope
investigation of the trophic exploitation of cow pats by
epigeic and endogeic earthworms. Rapid Communications
in Mass Spectrometry 22:1643–1652.
Journal of the North Atlantic
19
2016 No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Dungait, J.A.J., L. Cardenas, M. Blackwell, L. Wu, A.
Whitmore, P. Murray, D. Chadwick, R. Bol, A. Macdonald,
and K. Goulding. 2012. Future-proofing macronutrient
cycling in UK agricultural systems. Science
of the Total Environment 434:29–50.
Elhmmali, M.M., D.J. Roberts, and R.P. Evershed.
1997. Bile acids as a new class of sewage pollution
indicator. Environmental Science and Technology
31:3663–3668.
FitzPatrick, E.A. 1993. Soil Microscopy and Micromorphology.
Wiley, Chichester, UK.
French, C. 2003. Geoarchaeology in Action: Studies in
Soil Micromorphology and Landscape Evolution.
Routledge. London, UK.
Gebhardt, A. 1992. Micromorphological analysis of soil
structure modifications caused by different cultivation
implements. Pp. 373–381, In P.C. Anderson (Ed.).
Préhistoire de L’agriculture: Nouvelles Approches
Expérimentales et Ethnographiques. Monographie du
CRA no. 6, éd. CNRS. Paris, France.
Gibson, A. 2003. What do we mean by Neolithic settlement?
Some approaches, 10 years on. Pp.136–145, In
I. Armit, E. Murphy, E. Nelis, and D. Simpson (Eds.).
Neolithic Settlement in Ireland and Western Britain.
Oxbow Books, Oxford, UK.
Grime, G., and E. Guttmann-Bond. 2011. The use of PIXE
for the identification of plaggen soils. X-Ray Spectrometry
40:210–214.
Guttmann, E.B. 2001. Continuity and change in arable
land management in the Northern Isles: Evidence from
anthropogenic soils. Ph.D. Dissertation. University of
Stirling, Stirling, UK.
Guttmann, E.B.A. 2005. Midden cultivation in prehistoric
Britain: Arable crops in gardens. World Archaeology
37(2):224–239.
Guttmann, E.B.A., S.J. Dockrill, and I.A. Simpson. 2004.
Arable agriculture in prehistory: New evidence from
soils in the Northern Isles. Proceedings of the Society
of Antiquaries of Scotland 134:53–64.
Guttmann, E.B., I.A. Simpson, and D.A. Davidson. 2005.
Manuring practices in antiquity: A review of the evidence.
Pp. 68–76, In M. Brickley and D. Smith (Eds.).
Fertile Ground: Papers in Honour of Susan Limbrey.
Oxbow Books, Oxford, UK.
Guttmann, E.B., I.A. Simpson, D.A. Davidson, and S.J.
Dockrill. 2006. The management of arable land in
prehistory: Case studies from the Northern Isles of
Scotland. Geoarchaeology 21(1):61–92.
Herity, M., and G. Eogan. 1977. Ireland in Prehistory.
Routledge and Kegan Paul, London, UK.
Jongerius, A. 1983. The role of micromorphology in
agricultural research. Pp 111–138, In P. Bullock, and
C.P. Murphy (Eds.). Soil Micromorphology Vol. 1:
Techniques and Applications. AB Academic Publishers,
Berkhamsted, UK.
Leeming, R., A. Ball, N. Ashbolt, and P. Nichols.1996.
Using faecal sterols from humans and animals to distinguish
faecal pollution in receiving waters. Water
Resources 30(12):2893–2900.
Lewis, H. 1998. The characterisation and interpretation
of ancient tillage practices through soil micromorphology:
A methodological study. Ph.D. Dissertation.
University of Cambridge, Cambridge, UK.
Linderholm, J. 1997. Prehistoric land management and
cultivation. A soil chemical study. Bulletin 1 of the Archaeological
Soil Micromorphology Working Group,
University College London, London, UK. Pp. 9–16.
Long, C.B, C.V. MacDermot, J.H. Morris, A.G. Sleeman,
D. Tietzsch-Tyler, C.R. Aldwell, D. Daly, A.M. Flegg,
P.M. McArdle, and W.P. Warren. 1992. Geology of
North Mayo: A geological description to accompany
the bedrock geology 1:100,000 map series; Sheet 6,
North Mayo. Geological Survey of Ireland, Dublin,
Ireland.
MacLeod, G. 2008. Thin section and micromorphology
at the University of Stirling—Methods: Impregnation.
Available online at http://www.thin.stir.
ac.uk/2008/06/03/methods-impregnation/.
Macphail, R., J.C.C. Romans, and L. Robertson. 1987. The
application of micromorphology to the understanding
of Holocene soil development in the British Isles with
special reference to early cultivation. Pp. 647–656, In
N. Fedoroff, L.M. Bresson, and M.A. Courty (Eds.).
Micromorphologie des sols. Association Française
pour l’Étude du Sol (AFES), Paris, France.
Macphail, R.I., M.A. Courty, and A. Gebhardt 1990. Soil
micromorphological evidence of early agriculture in
northwest Europe. World Archaeology 22(1):53–69.
McGowan, G., and J. Prangnell. 2006. The significance of
vivianite in archaeological settings. Geoarchaeology
21(1):93–111
Mikkelsen, J.H. 1997. Laboratory method for determination
of organic, inorganic, and total phosphate. Bulletin
1 of the Archaeological Soil Micromorphology
Working Group. University College London, London,
UK. Pp. 5–8.
Molloy, K., and M. O’Connell. 1995. Palaeoecological
investigations towards the reconstruction of environment
and land-use changes during prehistory at Céide
Fields, western Ireland. Probleme der Küstenforschung
im südlichen Nordseegebiet 23:187–225.
Nielsen, B.O., V. Mahler, and P. Rasmussen. 2000. An arthropod
assemblage and the ecological conditions in a
byre at the Neolithic settlement at Weier, Switzerland.
Journal of Archaeological Science, 27:209–218.
O’Connell, K., and M. Molloy. 2001. Farming and woodland
dynamics in Ireland during the Neolithic. Biology
and Environment: Proceedings of the Royal Irish
Academy 101B(1–2):99–128.
Ottaway, J.H. 1984. Persistence of organic phosphates in
buried soils. Nature 307:257–259.
Peters, C., M.J. Church, and C. Mitchell. 2001. Investigation
of domestic fuel sources on Lewis using mineral
magnetism. Archaeological Prospection 8:227–237.
Poincelot, R.P. 1972. The biochemistry and methodology
of composting. Bulletin 727.The Connecticut Agricultural
Experiment Station, New Haven, CT, USA.
Renou, F., and E.P. Farrell. 2005. Reclaiming peatlands
for forestry: The Irish experience. Pp. 541–557, In
J.A. Stanturf and P.A. Madsen (Eds.). Restoration
of Boreal and Temperate Forests, CRC Press, Boca
Raton, FL, USA.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
20
Simpson, I.A., R. Bol, S.J. Dockrill, K.-J. Petzke, and
R.P. Evershed. 1997. Compound-specific δ15N amino
acid signals in palaeosols as indicators of early land
use: A preliminary study. Archaeological Prospection
4(3):147–152.
Simpson, I.A., S.J. Dockrill, I.D. Bull, and R.P. Evershed.
1998. Early anthropogenic soil formation at Tofts
Ness, Sanday, Orkney. Journal of Archaeological Science
25:729–746.
Simpson, I.A., R. Bol, I.D. Bull, E.P. Evershed, and K.
Petzke, K. 1999a. Interpreting early land management
through compound specific stable isotope analyses of
archaeological soils. Rapid Communications in Mass
Spectrometry 13(13):1315–1319.
Simpson, A.A., P.F. van Bergen, V. Perret, M. Elhmmali,
D.J. Roberts, and R.P. Evershed. 1999b. Lipid biomarkers
of manuring practice in relict anthropogenic
soils. The Holocene 9:223–229.
Thomas, J. 1991. Rethinking the Neolithic. Cambridge
University Press, Cambridge, UK.
Thomas, J. 1999. Understanding the Neolithic. Routledge,
London, UK.
Verrill, L., and R. Tipping. 2010. Use and abandonment
of a Neolithic field system at Belderrig, Co. Mayo,
Ireland: Evidence for economic marginality. The Holocene
20(7):1011–1021.
Warren, G. 2004. Belderrig quartz scatter. Unpublished
report, Department of Archaeology, University College
Dublin, Republic of Ireland.
Whittle, A. 1996. When did Neolithic farmers settle
down? British Archaeology 16:7.
Wild, A. 1993. Soils and the Environment: An Introduction.
Cambridge University Press, Cambridge, UK.
Wilson, C. 2000. Processes of post-burial change in archaeologically
buried soils. Unpublished Ph.D. Dissertation.
University of Stirling, Stirling, UK.
Journal of the North Atlantic
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E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Area TP Top sod Humified peat Buried soil Sub-soil Till
Belderg Beg A -109 (108) humic
silt. (112) sandy
loam 10YR 3/2.
Midden layers
(130, 131, 132)
Belderg Beg B (135) Black -110 (134) 10YR 4/4
sandy silt
Belderg More C (100) 5YR 4/6 7.5YR 2.5/2 (101) 10YR5/4
soft clayey silt,
v. frequent large
stones, peat
mottles
10YR5/4 large
stones, poorly
sorted
Belderg More D (102) 5YR5/6 (104) 10YR5/3
clayey silt with
gleying
(105) 10YR5/4
frequent large
stones, poorly
sorted
Area E E (113) Black,
humified
(115) 10YR2/2
brown peaty silt
(115) 10YR3/2
silt loam
10YR5/3
Belderg Beg F (136) 10YR2/2
sandy silt
10YR 4/6
compact,
50–60% large
stones
Céide Fields G (124) Black
humified peat
(121) 10YR2/2
organic clayey
silt
(125) 10YR4/3
brown,
compact,
frequent large
stones
Céide Fields H (122) Black (123) 10YR4/2
dark greyish
brown soft
clayey silt
(129) 10YR3/2
and 10YR4/3
very compact
silty clay,
10–20% poorly
sorted stones
Gley 1 4/10Y
dark greenish
grey
Céide Fields I (117) Black (118) 10YR3/2
silty clay
(119) 10YR2/2
silty clay
(120) 10YR4/2
compact clayey
silt
Céide Fields J (126) Black,
moderately
humified, freq
rootlets
(127) 10YR3/2
very dark
greyish brown
organic rich
clay-silt
(128) Mottled
10YR3/2 and
5Y4/2 olive
grey. Gleyed,
decayed
sandstone.
Belderrig,
(analyzed for
UCD)
K -133 (107) 10YR 4/3
soft clayey silt.
20–30% poorly
sorted stones,
2–5% charcoal
flecks
Appendix 1. Field descriptions, showing area, test pit, and con texts (in brackets).
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
22
Area TP Top sod Humified peat Buried soil Sub-soil Till
Céide Fields 1 (221) Black,
humified
( 222) 10YR2/2
very soft clayey
silt
(223)
10YR3/1silty
clay
Gleyed till
Céide Fields 3 (224) Black,
fairly well
humified
( 225) Black,
humified peat,
clayey
(226) Compact stony
till
Céide Fields 4 (218) Black,
fairly well
humified
(219) Black,
Well humified,
clayey
(220) 10YR3/2
silty clay,
frequent
sandstone,
occassional
charcoal
Rathlackan 5 Fibrous (202) Black,
well humified
( 203) 10YR2/2
v dark brown
clayey silt,
frequent rootlets
Stony till
Rathlackan 6 (200) Black,
well humified,
frequent rootlets
(201) 10YR2/2
silty clay loam
Rathlackan 7 (204) Black and
orange
(205) 10YR2/1 (206) 10YR3/2
Rathlackan 8 (208) Black,
humified
(209) Dark
brown humic
clay
Yellow brown
silty clay, sandy
inclusions
Rathlackan 9 (210) Black,
humified,
frequent roots
and rootlets
(211)10YR2/2
to 10YR 4/4,
clayey silty,
mottled very
dark brown,
paler with
depth.
Rathlackan 10 Fibrous peat (214) Black,
fairly well
humified,
moderate
rootlets
(215) 10YR2/2
clayey silt
10YR5/3
Rathlackan 11 (212) Black
peat. Darker,
denser band at
base.
(213) 10YR2/2
dark brown,
frequent
sandstone
Rathlackan 12 (216) Black (217) 10YR2/2
dark brown
clayey silt,
occassional
small stones
Céide Fields 18 Reddish, fibrous
peat
(242) Black, v
humified
(243) 10YR2/2
silty clay,
occassional
small stones
Compact, with
large stones
Journal of the North Atlantic
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2016 No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Area TP Top sod Humified peat Buried soil Sub-soil Till
Céide Fields 19 (227) Black (228) 10YR
2/2 very dark
brown, m paler
mottles (10YR
3/2) occassional
small stones
Céide Fields 20 (244) Band of
charcoal within
peat
(245) 10YR2/1
Black, well
humified,
freq roots and
rootlets
(246) 10YR2/1,
occ stones, occ
charcoal flecks.
Near field
wall at base of
slope; possible
lynchet?
(247) 10YR3/2,
distinct from
till below, paler
than horizon
above
Compact
Céide Fields 21 (248) 10YR2/1
Very dark
brown humified
peat
( 249) 10YR
very dark brown
clayey silt,
occassional
charcoal,
occassional
stones
(250) 10YR3/3
dark brown silty
clay, moderate
stones,
occassional
charcoal
Very stony
compact till
Area E 22 Dark brown (229) Black,
well humified,
freq rootlets
(230) 10YR3/2
dark brown
clayey soil,
sandstone
inclusions
Stony till
Area E 23 (231) Black,
well humified,
frequent rootlets
(232) 10YR3/2
clayey silt, very
soft
10YR4/3 and
4/4 Sandy clay
loam, ~30%
stones up to 28
cm
Area E 24 (233) Black,
humified
(234) 10YR3/2
silty clay, very
soft, frequent
rootlets
10YR4/3
frequent
blackened
rootlet holes
Area E 25 (235) Very dark
black, humified,
occassional
rootlets
(236) 10YR3/3
light brown,
clayey,
occassional
large sandstone
fragments up to
15 cm
Céide Fields 26 (251) 10YR 2/1
black, humified
(252) 10YR3/2
very dark
brown, as
thin as 1cm in
places. Roots,
rootlets
Stony—large
stones
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
24
Area TP Top sod Humified peat Buried soil Sub-soil Till
Céide Fields 27 (237) Black,
well humified.
Overlies
possible wall.
(238) 10YR2/2
organic clayey
soil with
occassional
charcoal. Buried
soil? Overlies
stones of
possible wall.
(239) One
large stone
directly over
this layer; light
yellow brown
sandy silt,
friable, 20–25%
small stones.
Buried soil?
Part of wall
construction?
Céide Fields 28 (240) Banded
horizons;
disturbed?
(241) 10YR3/1
very organic
horizon. Roots,
no stones.
(253) 10YR4/2
silty clay,
10–20% small
stones under 10
mm.
Stony till. Gley
4/10Y dark
greenish grey.
Journal of the North Atlantic
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E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Appendix 2. Micromorphology Ceide, Belderrig and Rathlackan, 2004 and 2005. Key: + Very Rare (less than 0.5%), ++ Rare (0.5-2%), +++Very Few (2-5%), · Few (5-15%), ··
Frequent (15-30%), ··· Common (30-50%), ···· Dominant/Very Dominant.
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
A
Belderrig
midden
17, 18 108 Soil Complex. Spongy with
channels filled by organics.
Porphyric.
●● ●● ●●● ●● ●● 23
16
15
21
26
2–5% charred material up to 2mm.
LOI average 20
A
Belderrig
midden
18 109 Peat Complex. Spongy, with
channels, chambers and
cracks. Open porphyric.
+++ ● - ●●●● - - Peat shrinkage has altered structure.
Possible charcoal in peat. Very
pronounced horizontal laminations.
Channels contain decaying organic
material and porous excremental fabric.
A
Belderrig
midden
17 112 Layer Spongy, with channels.
Very compressed granular
fine fabric (dense and very
dense excremental fabric).
Porphyric.
●●● ●● ●● ●● ● 5 2–5% charred peat and charcoal. Very rare
phytoliths. Porous, dense and very dense
excremental fabric.
B
Belderrig
56 110 Soil Spongy structure with
channels, chambers and
vughs. Porphyric.
●● ●● ●●● ● ●● 22
17
Channels filled by decaying rootlets.
Wholly excremental fabric, porous to
dense. 2–5% charred peat and charcoal.
Very rare diatoms, very rare phytoliths.
Very rare spherulites.
C
Belderrig
3 100 Redeposited
peat
Crack structure; less than 2%
channels and chambers.
++ +++ - ●●●● ●●●● 96 Less than 2% fine sand and silt. Rare
phytoliths, v. rare pollen grains,
rare fungal sclerotia, v. rare porous
excremental pedofeatures.
C
Belderrig
3 101 Soil Channel structure with
vughs. Porphyric.
●● ●● ●●● +++ ●● 32
27
D
Beldering
6 103 Redeposited
peat
Channel and chamber with
cracks. Open porphyric.
+ ●● - ●●●● - - Multiple fabrics. Context is disturbed.
Field observations suggest the disturbance
was probably by peat cutting.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
26
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
D
Beldering
6 104 Soil Spongy structure with
channels. Open porphyric.
●● ●● ●●● +++ ●● 18
19
2–5% charred material.
E
control
37 229 Peat Channel, chamber and crack.
Open porphyric.
++ ● ●●●● ●● _ _ 5-10% charred peat. Excremental fabric.
Yellow-brown B-fabric looks more like
soil than peat. Organic material fills c.
95% of voids.
E
control
37 230 Soil Massive, with organic-filled
channels and vughs. Close
porphyric.
●●●● ++ ●●● ●●● - - 0.5–2% charred peat. Rare phytoliths,
including distinct dumbbell shaped. Very
rare pollen. Rare porous excremental
fill in voids. Dense and very dense
excremental fine fabric.
E
Control
(TP23)
38 232 Soil Massive, with organic
material filling channels,
which are mainly vertical.
Close porphyric.
● ● ●●●● ●● - - 5–10% charred peat. Rare phytoliths. Rare
very dense excremental fabric.
G
Céide
arable?
36 124 Peat Channels and cracks. Open
porphyric.
+++ ●● - ●●●● - - Typical red, fibrous peat. Contains charred
peat and charcoal.
G
Céide
arable?
36 121 Soil Crack and channel structure,
channels predominantly
vertical and contain organics
(rootlets). Open porphyric.
● ●● ● ●●●● ●●● 48 Very rare fungal sclerotia, very rare
phytoliths and pollen. Rare charred
woody material. Dense and very dense
excremental fabric; very rare porous
excremental fabric.
G
Céide
arable?
48 125 Till? Complex; crack and channel
but mainly massive structure
with fairly well sorted silt,
very fine sand and fine sand.
Close porphyric.
●●●● ●● ●● ●● ●● 15
H
Céide
37 122 Peat/soil Horizontal cracks and
vertical channels. Open and
close porphyric structure
●● ●● +++ ●●●● ● 39 Very mineral-rich for a peat deposit.
Journal of the North Atlantic
27
2016 No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
H
Céide
37 123 Soil Crack and channel structure;
close porphyric.
●●● ●● ● ●● ● 11 Very rare diatoms. Dense excremental
fabric.
H
Céide
46 129 Sub-soil or
till
Channel and chamber. Fine
fabric shows angular blocky
structure. Porphyric.
●● ●● ●● ●● ● 9 Channels filled by decaying rootlets. Rare
dense and v. dense excremental fabric.
I
Céide enclosure
49 117 Peat Complex: channels,
chambers and cracks.
Porphyric.
●● ●● - ●●●● ● 19 Decayed organics in some channels. 2–5%
charred peat. Interface with soil below
(118) is gradual; channels penetrate into
118. Cracks are horizontal and channels
are vertical.
I
Céide enclosure
49 118 Silty clay Spongy, with channels.
Close porphyric.
●●●● ●● ●● ● ● 7 Very rare charred peat, very rare charcoal.
Very rare phytoliths, very rare pollen. Peat
in channels comminuted by soil biota/
microbes. Fine fabric porous to very
dense excremental, esp. near top of layer.
Several microfabrics present.
I
Céide enclosure
26 119 Silty clay Channels, filled by ironenriched
rootlets with mainly
vertical orientation. Close
porphyric.
●●● ●● ●●● ● ● 11 Rare phytoliths, very rare pollen. Dense
and very dense excremental. fabric.
Occasional channels contain dense and
very dense excremental fabric. Very rare
porous excremental fabric.
I
Céide enclosure
26 120 Till Channel structure,
predominantly vertical and
filled by organic material
(decayed roots). Open
porphyric.
●●● ●●● ●●●● ●● ● 5 Dense excremental fabric and decaying
peat in channels.
J
Céide
Pasture?
45 126 Peat Structure includes channels,
chambers and cracks.
++ ●● - ●●●● ●●●● 91 5–15% charred peat and charcoal.
Organic-filled channels cut through thin
horizontal laminated peat.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
28
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
J
Céide
Pasture?
44, 45 127 Soil Channel structure. Root
channels contain decaying
organic material. Porphyric.
●●●● ●● ●● ● ●● 27 Dense and very dense excremental fabric,
including infilled worm channels which
are filled by compact, darker and more
humic fine fabric.
K
Céide
Pasture?
8 133 Peat Channel, chamber and crack.
Open porphyric.
+ ● - ●●●● - - 2–5% charcoal. Dense, fibrous dark red
peat.
K
Céide
Pasture?
8 107 Soil Channel structure, vertical
orientation to channels. Very
close porphyric.
●●●● ●● ●● ● ● 9 2–5% charcoal, up to 60μm. Fabric
predominantly dense and vry dense exc.
fabric. Very rare porous excremental
fabric.
1
Céide
9 221 Peat Complex: channel and crack,
but also platy near surface.
+++ ++ - ●●●● - - Peat is coalescing and becoming
comminuted into excremental fine fabric
with a granular structure
1
Céide
9 222 Soil Channels up to 2 mm wide.
Close porphyric.
●● ● ●●●● ● - - Rare charcoal, rare charred peat. Charcoal
lens in peat above buried soil. Very rare
phytoliths. Moderate birefringence;
reticulate striations (clay domains). Very
rare porous and rare dense exc. fabric.
Pendant, crescent and typic hypocoatings
of dusty clay (inner) and limpid clay
(outer).
3
Céide
12 225 Peat Channels and planar voids.
Open porphyric- mineral
grains rare.
++ ●●●● - ●●●● - - Excremental fabric
4
Céide
10 219 Peat Channels and cracks. Open
porphyric.
+++ +++ ●●● ●●● - - Horizontal laminations made up of
compressed organic material. Rare
charcoal.
Journal of the North Atlantic
29
2016 No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
4
Céide
10 220 Soil Channel and chamber. Close
porphyric.
●● ● ●●● ●● - - Very rare charcoal, probably wood. Very
rare phytoliths. Areas of concentrated clay
domains; possibly fragmented plough
pan? Chambers filled by organics. Dense
and very dense exc. fabric occurring very
rarely in channels.
18
Céide
13 242 Peat Complex: platy, with
channels and cracks. Open
porphyric, with rare mineral
grains.
++ ● ●●● ●●●● - - 5–10% charred material.
18
Céide
13 243 Soil Channel structure; roots
infilling channels. Porphyric.
● ●● ●●●● ●● - - Horizon is sealed by a birefringent clay
and silt horizon, which itself is sealed by
an organic peat layer. 5–10% charred peat.
Contains horizontal lenses of peat. Rare
dense and very dense excremental fabric;
very rare porous.
19
Céide
14 227 Peat Channel structure. Open
porphyric.
++ ● ●●●● ●● - - Large channels, charred peat. Fine fabric
includes excremental fabric.
19
Céide
14 228 Soil Close porphyric. Crack
and channel structure. Two
fabrics: a more organic-rich
one appears in occasional
channels and chambers,
indicating worm activity.
●● ●● ●●●● ●● - - 2–5% charred peat. Decaying organic
material in channels (roots). Very rare
phytoliths and diatoms. Rare porous
excremental fabric; very rare dense.
20
Céide
16 245 Peat Platy structure, with
channels, chambers and
cracks.
+ ● ●●● ●●●● - - 2–5% charred peat containing mineral
grains. Organic material in horizontal
cracks. Channels mostly vertical.
20
Céide
16 246 Soil Very open porphyric. ~10%
silt to very fine sand. Fabric
looks like decayed peat (very
red fabric) with channels,
cracks and chambers.
++ +++ +++ ●●●● - - Very rare fungal sclerotia. Rare phytoliths;
areas of surviving plant remains with
sheets of intact phytoliths. Very rare
diatoms. Common dense and very dense
excremental fabric; very rare porous.
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
30
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine
fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
21
Céide
17 248 Peat Complex: platy with
channels and cracks; also
acrumb structure.
+ ● ●●●● ●● - - 2–5% charred peat. Organic material in
horizontal cracks. Fine fabric made up
of porous to dense excremental fabric,
coalescing into flat, platy aggregates.
21
Céide
17, 18 249 Soil Channel and chamber. Open
porphyric. Mineral material
predominantly silt and fine
sand.
● ● ●●●● ●● - - 0.5–2% charred peat. Excremental
fabric. Reticulate striations of clay
domains. Very rare fungal sclerotia. Rare
charcoal. Common dense and very dense
excremental fabric; very rare porous.
21
Céide
18 250 Sub-soil Cracks and organic-filled
channels. Very close
porphyric.
●●●● ● ●● +++ - - Buried sub-soil
26
Céide
19 251 Peat Cracks and root channels. ++ +++ ●●●● ● - - 5–10% charred peat. Rare phytoliths. Very
rare diatoms. Fine fabric all decayed peat?
26
Céide
19 252 Soil Channel and chamber.
Porphyric.
●● ++ ●●●● ●●●● - - 5–10% charred peat. Rare phytoliths.
Very rare diatoms. Fine fabric may derive
from decayed peat. Peat above grades into
this soil; B-fabric increases with depth.
Organic-filled channels and chamber.
Cracks and root channels. Very dense
excremental fabric.
5
Rathlackan
2 202 Peat/soil Channel and chamber.
Porphyric.
● ●● ● ●●● - - Identified as peat in the field, but has
fragments of peat within fabric; 5–15%
peat fragments up to 5 mm. Excremental
fabric, porous to dense. 5–10% organic
material with intact sheets of phytoliths.
5
Rathlackan
2 203 Soil Channels and chambers.
Porphyric.
●●●● ● ●● ●● - - Channels and chambers filled by organic
and decayed organic. Occasional dense
and very dense excremental fabric; very
rare porous in channels. Interpreted as
subsoil.
Journal of the North Atlantic
31
2016 No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
6
Rathlackan
1 200 Peat/soil Complex: channel and
chamber, crack, and crumb.
Open and close porphyric.
● ●●● ●● ●●●● - - Peat is disturbed; peat fragments occur in
a matrix of fine fabric and peat.Large (up
to 1 cm, mostly under 5 mm), frequent
peat fragments, similar to 202. Channels
filled by decaying organics and porous
excremental fabric. Fine fabric also
includes very porous to dense excremental
fabric. Very heterogeneous fabric.
6
Rathlackan
1 201 Soil Open porphyric. ●●●● ●●● ● ● - - Very rare charcoal, wood. Very rare
phytoliths. Very rare porous and very
porous excremental fabric in channels and
chambers. Very rare dense excremental
fabric.
7
Rathlackan
3 205 Soil Channel and chamber. Open
porphyric.
● ●●● ●● ●● - - Some channels infilled by organic
material. Rare porous to dense
excremental fabric in channels with very
decayed organics. Channels cut decayed
peat fragments.
8
Rathlackan
4 208 Soil Channel and chamber.
Porphyric.
● ●● ● ●●●● - - Very rare phytoliths and fungal sclerotia.
Rare charcoal up to 1mm and rare charred
peat. Very rare dense excremental fabric;
very rare porous excremental in channels.
9
Rathlackan
5 211 Soil Channel, slightly spongy.
Close porphyric.
●●● ●● ●● ●● - - 2–5% charred material. Rare phytoliths
and pollen. Very Rare fungal sclerotia.
Very rare, very dense excremental fabric;
low porositiy, deriving mainly from
channels left where roots have decayed.
10
Rathlackan
7 214 Peat Channels, chambers and
planar voids.
+++ ●● +++ ●●●● - - Excremental fabric within channels.
Interleaved fine fabric and organic
material. Rare charred material, fungal
sclerotia.
10
Rathlackan
7 215 Soil Channel and chamber. Open
porphyric
● ●● ●● ●●● - - 2–5% phytoliths, very well preserved.
Very rare charcoal. Organic material in
chambers. Excremental fabric, porous to
dense. Rare calcitic spherulites?
2016 Journal of the North Atlantic No. 30
E.B.Guttmann-Bond, J.A.J.Dungait, A. Brown, I.D.Bull, and R.P. Evershed
32
Test pit (for
location see Figs.
3, 4 and 5)
Sample Context Substrate Microstructure and related
distribution
% Mineral
% Porosity
% Fine fabric
% organic /
peat
Loss on
ignition
% loss on
Ignition
Notes
11
Rathlackan
6 212 Peat Channels and chambers.
Very open porphyric.
+++ ● +++ ●●●● - - Excremental fabric in channels and
chambers. Also decayed organic material
in channels. Very rare charcoal. Horizontal
compacted organic remains and planar
voids.
11
Rathlackan
6 213 Soil Channel and chamber. Open
and close porphyric.
●● ●● ● ●●● - - Organic material (rootlets) in channels.
Very rare phytoliths. Very rare charcoal.
Porous to dense excremental fabric.
12
Rathlackan
8 216 Redeposited
peat
Complex: channel, chamber,
crack and crumb. Open
porphyric
+++ ●● ●● ●●● - - 20–30% peat fragments up to 3 mm.
Fine fabric almost completely porous to
dense excremental fabric. Very mixed
and heterogeneous. Organic material with
intact sheets of phytoliths.
12
Rathlackan
8 217 Soil Channel and chamber. Close
porphyric.
●● ●● ● ●● - - Organic material in channels. Very rare
charcoal, 2–5% phytoliths, including
within intact plant remains. Very rare
diatoms. Rare dense and very dense
excremental fabric.