Publication Account

Date 2007

Event ID 587279

Category Descriptive Accounts

Type Publication Account

Permalink http://canmore.org.uk/event/587279

Euan W Mackie Broch Corpus 2

NB03 1 DUN BHARABHAT 1 ('Loch Baravat', 'Dun Baravat 1')

NB/0987 3530

This probable ground-galleried broch or massive gallery-walled round-house, together with submerged dun or roundhouse close by, in Uig, Lewis, are both situated on an small islet in a loch, about 21m (70 ft) from the end of an adjacent promontory and connected to it by a causeway (excavation visited in June 1985).

1. Introduction

Loch Baravat itself is about 30m (100 ft) above sea level and is surrounded by low stony hills [3, Plate 1]. A shallow ravine leads down from the surrounding ground towards the lower ground and the sea. The name of the loch evidently comes from the Norse 'Borgarvatn', meaning 'lake of the stronghold' (Thomas 1890, 388).

The land structure was originally classified as an island dun [2] but excavations by the Dept. of Archaeology, University of Edinburgh, from 1985-87 revealed that it was a gallery-walled broch or massive roundhouse; the term preferred by the excavator is “complex Atlantic roundhouse” (see Section 6.5 above). The explorations also revealed a succession of submerged smaller stone roundhouses next to the islet, which produced a large quantity of implements of wood as well as valuable environmental evidence. These structures were thought at first to be somewhat older than the building on the islet but the whole complex was probably occupied simultaneously. Certainly the material culture in both areas was similar, the pottery in particular being indistinguishable.

The work at Dun Bharabhat is of considerable significance because the true nature of the 'broch' or 'roundhouse' itself was not seen until excavation started. It turned out to be a somewhat anomalous structure which does not fit clearly into the standard categories of Hebridean Iron Age buildings and thus emphasises the point made by the excavator [3, 102 ff], and also in Section 6.5 above; there is a much greater variety of broch-like sites in the western maritime part of the Atlantic Province than on the mainland and the northern islands. The date of the building and of the associated material culture is clearly of first importance and has been pinned down reasonably well – though perhaps not as well as one would like – by radiocarbon measurements (below).

Another reason for the importance of Dun Bharabhat is that it has given us a new insight into the economy and organisation of an Iron Age island round-house and its community. If the extensive underwater excavations had not been carried out we would have no idea that the roundhouse had an annexe to it which was used for a variety of purposes, and little idea of the range of artifacts of organic materials which were used therein. One wonders how many other island brochs and duns had these outlying buildings, now submerged.

The first part of the excavation report has appeared [3]. However this entry gives a fairly detailed summary of the most important information therein, firstly because the site is important as explained, and secondly because the report is a publication of the Dept. of Archaeology in Edinburgh and may not be widely available outside Scotland. Only a selection of the pottery found is illustrated here.

2. The roundhouse

2.1 The structure

The oval building rises from the water's edge on all sides except on the east where there is about 3.6m (12 ft) of ground (it was in this wider area that the submerged structures were found). Much damage was done to the main building when a sheep dip was built nearby in about 1911 [2], but signs of the collapse of part of the wall in ancient times were also observed. No intra-mural features were noted before the excavations began. A causeway paved with stepping-stones connects the island with the shore to the east.

The roundhouse [4, frontispiece] encloses an oval area measuring 10.0m east/west by 11.5m north/south and has its entrance passage facing east, on the opposite side to the causeway (it is assumed that some kind of raised dry path ran round from the latter to the entrance). This passage is 1.0m wide at the exterior and has two built door-checks, with a sill stone in the floor between them, 0.8m from the exterior; behind the door-frame the passage widens to 1.4 m. The floor is paved – the paving extending into an outer forecourt – and a pivot stone was found behind the right check (most are on the opposite side), with bar-hole and socket in the wall above. The wall contains a series of short galleries (about 1.0m wide) and a stairway, suggesting that Dun Bharabhat is a ground-galleried broch. However with an average thickness of 3.0m it is relatively thin for a broch tower, though not uniquely so.

At 7.30 o'clock is the doorway to Gallery 1, 90cm wide at the inner end, which contains the stair of which seven steps remain [3, Plate 3]; a slight recess to the left of the doorway suggests a rudimentary stair-foot guard cell, and here there were several apparent stone lintels which had fallen to the floor when the outer half of the wall sagged outwards. At 12 o'clock is the 1.6m- wide doorway (widening to 2.0m) to Gallery 2 but the whole of this section runs anti-clockwise to behind the stair. The doorway is so wide that it must surely have been widened during a secondary stage of occupation and after the upper parts of the wall had collapsed or been removed.

At 3 o'clock is the narrow doorway, with its lintel still in position, to Gallery 3 which also runs only anti-clockwise from it, and looks rather like an elongated cell; it contained several stone lintels which had collapsed downwards [3, Plate 4]. This seems to imply the existence of at least one upper gallery in the original structure. At 4.30 o'clock is the 1.5m wide doorway, with a fallen lintel [3, Plate 5], to a large rectangular cell which the excavator thought might have been inserted into Gallery 3; indeed the outer wallface of this gallery was found to extend towards this cell [3, fig. 3] and the cell seems to have been taken back into part of the outer wall of the roundhouse. Here again this could only have been done if the original high wall had been taken down.

The floor of the central court was of earth, based on a foundation of rough boulders; there was no trace of internal paving. A round hearth of baked clay was found in the centre of the enclosed area and had had a stone kerb added to it during the secondary phase of occupation. No scarcement was found on the inner wallface but the poor state of preservation means that there may have been one higher up. Neither were there any clear signs of a raised doorway in the wall to which the stair might have led, and no post-holes in the interior are described. The evidence for that typical broch structural feature – the annular raised wooden floor resting on the stone ledge and on a ring of posts – is thus absent at this site.

There was abundant evidence that parts of the stone wall of the roundhouse had collapsed because of poor foundations. As noted the secondary changes to the stonework – notably the insertion of the rectangular cell to the right of the entrance and the widening of the doorway to Gallery 2 – presumably occurred at this time.

2.2 The occupation layers

The stratigraphy of the layers of the central court revealed at least three phases of occupation, the oldest of which pre-dated the roundhouse. This consisted of an extensive layer of black, peaty soil overlying a raft of cobbles; several lenses of red or orange in this were found to extend under the roundhouse wall. Waterlogging during the excavations inhibited a full exploration of this stratum which the excavator thought could either represent a pre-roundhouse occupation or activity related to the construction of the latter. A C-14 date was obtained for this level of –

2550 +/- 50 bp (GU-236)

and this calibrates to 820-520 BC at a 95.4% level of confidence [3, Table 1]. No finds came from this layer.

The next layer up was the primary occupation layer, resting on a platform of hard green clay which equated with the small area of paving extending inwards from the entrance. The layer itself was of dark earth which contained small potsherds, occasionally large numbers of them, which may have been crushed and thrown down to harden the floor layer. This horizon was not a single, uniform layer all over the interior but its nature seemed clear [3, 22-5 and figs. 10 and 11]. The clay central hearth was laid in this phase.

The second and final major habitation layer was the most obvious of the occupation strata in the roundhouse interior and the clearest element of this was a burnt layer – including many charred timbers – which signalled the destruction of the site at the end of its Iron Age use. The impression gained was that the timber roof frame had caught fire and collapsed into the interior and this and other aspects of the horizon are discussed in detail in the report [3, 20-2]. An important point is that this secondary occupation layer overlapped in places the slumped or partially collapsed wall of the original building. Two C-24 dates were obtained for charcoal from the destruction layer.

2100 +/- 50 bp (GU-2435

2010 +/- 50 bp (GU-2434)

These calibrate, first, to 200-50 BC at 10% probability or 250 BC - AD 10 at 90% probability and, second, to 100 BC - AD 30 at 68.2% probability.

A layer of earth was found in places on top of the destruction layer, and below the final collapse of rubble, and suggests that the building was used intermittently for some purpose when it was a roofless shell.

Site sequence. For convenience the sequence of occupation phases in Dun Bharabhat is here numbered; the correlation between these numbers and the excavator's terminology is –

Primary occupation (pre-roundhouse): Phase 1

Main or primary roundhouse occupation: Phase 2

Secondary (roundhouse) occupation: Phase 3a

End of secondary occupation – destruction: Phase 3b

Late Secondary occupation: Phase 4

Post-abandonment: Phase 5

2.3 The non ceramic finds

The catalogue of finds simply gives a Context for each; they are not grouped into the main phases of occupation just described, though this can be worked out by consulting the list of Contexts [3, 52-3]. Here the most important finds are grouped by Phase. The pottery is indistinguishable from that obtained in the submerged buildings so is discussed all together below, in Section 5.

Phase 1

Stone: 1 spindle whorl (070) with a flattened oval cross-section, diam. 42mm [3, fig. 14, no. 1].

Phase 2

Glass: 1 small ring bead of blue translucent glass (050), diam. 7mm.

Stone: 1 pebble hammerstone (087).

Phase 3a

Copper alloy working: 1 crucible (030).

Glass: 1 small ring bead of blue translucent glass (036), diam. 6mm: 1 small ring-bead of yellow glass, diam. 4mm: 1 fragment of red and yellow opaque glass bead (068) with approx. D-shaped cross-section, diam. 18mm.

Amber: 1 fragment of orange-red amber bead (085), diam. c. 15mm.

Stone: 1 quartzite pebble strike-a-light, used on both faces (100), length 69mm.

Phase 3b

Copper alloy working: 3 small crucibles (no numbers).

Glass: 1 globular bead (037) with approximately hexagonal cross-section at right angles to the perforation, of yellow glass with dark brown spiral inlay: diam. 15mm.

Stone: 1 whetstone with square cross-section (no number), length 57mm; two-handed pebble-pounder (083).

Fired clay:1 spindle whorl made from a cut-down sherd (010), diam. c. 75mm.

Phase 4

Stone: 1 globular pebble probably used as a polisher (080), diams. 63 x 72mm; 1 quartzite pebble strike-a-light, used on both faces (no number), length 72mm; 2 pebble hammerstones (both un-numbered).

Phase 5

Lead: 1 strip, perforated at each end (001), perhaps a weight.

Iron; 2 bolts (029 and un-numbered).

Glass: quarter of 1 small yellow ring bead (031), diam. 6.5mm.

Stone: 2 pebble hammerstones (both un-numbered).

3. The submerged buildings

3.1 Introduction

Underwater excavations were also carried out off the east end of the islet with the initial aim of locating midden material thrown into the loch from the roundhouse. However the underwater stone structures were soon found to be much more extensive than had been suspected and the project was enlarged, not without encountering practical difficulties due to silt in the water. The preservation of organic material – heather and straw as well as artifacts of wood and bone – was found to be very good.

3.2 Structures

The earliest structure found was a stone platform made by dumping boulders into the shallow water, and this had evidently sunk into the loch bed, to depth of 3m below the modern surface; a thick layer of heather and occupation debris were found on it, so it had clearly served as a floor of some kind for a considerable period, probably beginning before the second roundhouse (below) was built on it. The entire complex seems to have been steadily subsiding throughout its use.

This roundhouse, presumably an annexe to the main building on the islet, was a sub-circular structure with traces of some form of intra-mural spaces, presumably galleries [3, fig. 27]; it measured internally about 4.8 x 3.6 m, very much smaller than analogous buildings classified as brochs and roundhouses. It was found to have two main periods of use. Part of this building was submerged and part on the islet [3, fig. 3]. From the beginning of Phase 1 thick occupation deposits began to accumulate in the interior, on top of a thick layer of peat blocks – covered with small pebbles and then with a layer of white beach sand – which served as the floor foundation. After occupation began layers of straw, heather and peat were laid down and these of course were mingled with occupation debris. The nature of the finds suggested that the annexe served initially as a workshop.

In its second phase of use continuing subsidence required the rebuilding of much of the wall of the annexe (Structure 2) with a new doorway slightly east of the old one, and several features were added to this during its occupation [3, 63]. Finally the building was dismantled and, some time later another stone house – Structure 3 – was erected on its foundations, though not following the earlier walls. The wall immediately east of the main roundhouse could be part of this final stage of the annexe, and habitation layers were found outside it – and on top of the remains of Structure 2 – which seemed to relate to it.

An important point about the various well preserved floor layers in the structures of the annexe (and one which surely relates to the level of Iron Age society to which the inhabitants of the islet belonged) concerns the distance which some of them had to be carried [3, 66-7]. Peat and heather could doubtless be collected locally two thousand years ago but Loch Bharabhat is in the middle of rocky uplands entirely unsuitable for arable farming which would have been done on the machair fringing the extensive beach Traigh na Berie about a kilometre to the north-east. The submerged floor deposits of the annexe were composed of straw and heather in alternate layers and straw had to be brought up the ravine to the loch from the fields. The same applies to the large quantities of white beach sand which were laid down at the beginning on top of a packing of peat blocks; this must likewise have been carried up to the site from a distance. It is possible also for the same reason – distance from the fields – to doubt that the inhabitants of the islet themselves grew crops [3, 68-9].

3.3 Phases and dates

Two radiocarbon dates were obtained for material from the submerged buildings; both were thought to date the occupation of Structure 3, presumably near the end of the use of the site as a whole. The dates are –

1810 +/- 110 bp (GU-2437)

1460 +/- 130 bp (GU-2438)

Calibrated to a probability level of 68.2% the dates give time spans of AD 70 - 340 and AD 420 - 680 respectively. They agree with and amplify the dates for the secondary occupation of the main roundhouse, and indicate that occupation of the islet continued well into the 1st millennium AD (see 'Discussion').

3.4 Finds

As noted below the information in the report does not allow one to attribute the finds from the submerged structures to specific phases of occupation. The only artifacts giving a terminus post quem for an occupation horizon are the pieces of lead; no lead is known to have been in use in Scotland before the arrival of the Roman army in the late AD 70s, so a lead object in the Outer Hebrides can hardly have been lost before the very end of the 1st century AD at the earliest.

Copper alloy [3, fig. 40]

These included 1 ring-headed pin of bent wire of North British type (with projecting head), 1 pin with a domed nail-like head and a shaft with a square cross-section, found with a dome-shaped cap, presumably hollow (these two pieces were found with one of the broken spiral finger-rings (no. 8)), 1 small penannular ring 9mm in diam., 3 penannular finger-rings, all with slightly overlapping terminals, and 2 penannular finger-rings with no signs of overlap.

From the drawings three of the five finger-rings appear to be parts of broken spiral rings, although not identified as such by the excavator.

Lead [3, fig. 40]

A lead alloy link.

Stone [3, fig. 39]

These included about a quarter of a worn, flat, discoid rotary quern with the handle-hole worn through to the grinding surface, a quartzite pebble strike-a-light, 2 stone grinders (with faceted grinding surfaces) made of large pebbles, and a spindle whorl.

Fired clay [3, fig. 41]

1 fine crucible with pouring lip and 1 coarse bowl-shaped example, 12 'miniature crucibles', and 1 bead with a very narrow perforation.

Bone and antler [3, fig. 38]

These included points, a handle, a weaving comb with wide-spaced teeth (of whalebone), and several large pieces of antler, presumably raw material.

Wood [3, figs. 32-37]

A large number of well preserved wooden objects were found of which the most interesting are mentioned here (it should be noted that the captions for figs. 35 and 37 are reversed [3, 71 and 76]). They include toggles, a grooved bung, a spindle, a spool, a variety of cut points, handled cups or scoops, a carved animal head, a double bead, a possible bow drill, a “baton” and a possible thatching tool. There was also the remains of a peat basket made of withies, not listed in the finds catalogue [3, Plate 12].

Other vegetable matter [3, fig. 35]

A length of heather rope.

4. The pottery

As noted all the pottery from the excavated areas – both dry and submerged – was composed of the same basic forms of vessels with similar decoration on each type. Nor was any clear ceramic sequence uncovered so, for both these reasons, the material can in effect be treated as a single group [3, 32]. The discussion in Section 5 attempts to put the pottery of Dun Bharabhat and similar Hebridean sites in a wider context so only a few specific comments are made here. In Harding and Dixon 2002 the pottery is drawn at two different scales. That from the round-house (figs. 16-23) is at 1:3 while that from the submerged building (Figs. 42-48) is at 1:4.

Most of the diagnostic pottery was found in the secondary occupation levels (Phases 3a and 3b here) so a meaningful ceramic sequence could not be estab-lished. Thus the assemblage represents the traditions of what was presumably a single kin group who lived in the roundhouse from sometime in the latter part of the first millennium BC until perhaps the 1st or 2nd centuries AD (though this lower limit is unclear).

The dominant form seems to be the 'hole-mouth jars' which are very similar to the Vaul ware urns found on Tiree in a stratified sequence going back at least to the 6th and probably to the 7th centuries BC and extending forward probably to AD 500 (NM04 4). Likewise at this Harris site the vessel is said to be the oldest form stratigraphically. However – as often seems to be the case in the Outer Hebrides – there is a greater mixture of formal and decorative features than at the Tiree site. For example at least one of the large urns has a footless base like an Everted Rim jar instead of the usual footed base. However the incised decoration on these pots broadly resembles that on Tiree.

The smaller Vaul ware vases also occur, though in fewer numbers [3, fig. 21, nos. 15 and 17]. The cordoned version (known as the Balevullin vase, after the type site on Tiree) is also present [Ibid. no. 18]. One of the latter vases is unusually large with a mouth diameter of 48cm (18.5 in) [3, fig. 16, no. 1].

Another very obvious hybrid has two classic features of the Everted Rim jar – the sharply everted and straight rim and the applied waist cordon moulded into a zig-zag pattern – but which also has the typical geometric incised pattern of Vaul ware vases.

Thus the dominant impression from the pottery is that Dun Bharabhat was inhabited by people using the indigenous pottery of the Western Isles, originating in the late Bronze Age. However many signs of the later Everted Rim ware are present [3, fig. 18]; the lips on these jars are much more sharply turned out than on the Vaul vases. In the classic form there is a distinct ridge at the angle between the inner surface of the lip and the interior, for example in no. 13 from the submerged structures [3, fig. 42]. However these jars, though usually decorated with a horizontal applied cordon as on Tiree, rarely have the characteristic pattern of the Clettraval style of Everted Rim ware which is so common in the west – the motif formed of a series of concentric channelled arches running round above the cordon, sometimes known as 'arcading'.

One rimless fragment is illustrated with this motif though it is crudely incised rather than channelled, but this tends to reinforce the view that the decorative motifs which are so clearly linked with the Clettraval style on Tiree are here more jumbled up with those of the more ancient Vaul ware styles.

Sources: 1. NMRS site no. NB 03 NE 4: 2. RCAHMS 1928, 21, no. 72: 3. Harding and Dixon 2000.

E W MacKie 2007

Continued...Part 2 Event ID 587279.