Machen Quarry extension, Carphilly

Machen Quarry Extension Archaeological field evaluation January 2009

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A report for Hanson Aggregates by Rowena Hart BSc MA

GGAT report no. 2009/002 Project no.P1130 National Grid Reference: ST 23108 89449

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The Glamorgan-Gwent Archaeological Trust Ltd Heathfield House Heathfield Swansea SA1 6EL

Machen Quarry extension, Caerphilly: archaeological field evaluation

Contents

Page

Summary .................................................................................................................................. 2 Acknowledgements .................................................................................................................. 2 Copyright notice....................................................................................................................... 2 1. Introduction ........................................................................................................................ 3 1.1 Project background and commission............................................................................ 3 1.2 Location and Topography ............................................................................................ 3 1.3 Geology ........................................................................................................................ 3 1.4 Historical and archaeological background ................................................................... 5 2. Methodology ....................................................................................................................... 7 3. Results ................................................................................................................................. 9 3.1 Finds ........................................................................................................................... 19 4. Conclusion......................................................................................................................... 23 Appendix I: Context Inventory............................................................................................... 25

Figures Figure 1. Site location .................................................................................................................. 4 Figure 2. Plan showing location of Trenches 1-5 and MQ1. Inset showing location of section drawings in Trenches 1 and 2............................................................................................... 8 Figure 3. East facing section in Trench 1................................................................................... 12 Figure 4. North and east facing section in Trench 2 .................................................................. 13 Figure 5. Flint blade (scale 1:1) and Mesolithic flint (2:1) below ............................................. 22

Plates Plate 1. Trench 1. Showing clearance cairn 104. View to the south west.................................. 14 Plate 2. Trench 1. North facing section showing proximity of the limestone bedrock to the ground surface. ................................................................................................................... 14 Plate 3. Trench 1. South facing section showing proximity of the bedrock to the ground surface. ............................................................................................................................... 15 Plate 4. Trench 1. Oblique view of the west facing section showing the shallow bedrock. ...... 15 Plate 5. Trench 2. Showing stony clay 203. View to north........................................................ 16 Plate 6. Trench 2. South-west corner showing clearance cairn (206). View to south-west....... 16 Plate 7. Trench 3. South-facing section showing clearance cairn (307). Oblique view to north west. ................................................................................................................................... 17 Plate 8. Trench 4. View to the north showing clearance cairn 403 and shallow bedrock 404... 17 Plate 9. Trench 4. View to the east showing very shallow and outcropping bedrock 404. The possible leading face of a small quarry area continuing to the east. .................................. 18 Plate 10. Trench 5. View to the south-east. showing shallow and outcropping bedrock........... 18

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Summary Hanson Aggregates commissioned the Glamorgan-Gwent Archaeological Trust (Projects Division) to carry out an archaeological evaluation on land to the north of the existing quarry, in advance of extension works centred at NGR ST 23108, 89449. The evaluation was carried out during November 2008. Five evaluation trenches were excavated on the previously identified area of archaeological potential within the extension area (MQ1). The trenches revealed a number of late postmedieval or modern clearance cairns and areas of bedrock outcropping to the present ground surface. No deposits of archaeological significance were encountered. Four flint artefacts were recovered and retained for specialist analysis. The resulting report outlined that the assemblage was typical of those found in upland environments and probably the result of casual loss rather than representing evidence of settlement or occupation. The archaeological evaluation was carried out to the standards specified by the Institute for Archaeologists Standard and Guidance For Archaeological Field Evaluation 1994. Acknowledgements This project was managed by Richard Lewis BA MIFA and the fieldwork undertaken by Rowena Hart BSc MA, Rachel Bowden BA, Ellie Graham BA, Andrew Sherman BA and Chris Bentham BA. The photographs and report were prepared by Rowena Hart BSc MA, with illustrations by Paul Jones (GGAT Senior Illustrator). Copyright notice The copyright of this report is held by Glamorgan-Gwent Archaeological Trust Ltd; GGAT has granted an exclusive licence to Hanson Aggregates and their agents to use and reproduce the material it contains. Ordnance Survey maps are reproduced under licence (AL 10005976), annotations are GGAT copyright.

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1. Introduction 1.1 Project background and commission Planning consent has been granted for a 5ha extension to Machen Quarry, Machen, Caerphilly (Application No. P/05/1100). One of the conditions attached to the consent states that “no development should take place within the extension area until the applicant has secured the implementation of a programme of archaeological works in accordance with a written scheme of investigation which has been approved in writing by the Mineral Planning Authority.” The scheme (Dunning 2006) allowed for an archaeological field evaluation to be conducted on a feature identified in a previous archaeological assessment of the extension (Tuck 2004). The purpose of the evaluation was to elucidate the extent and nature of the feature, as well as to outline any further works that may be required to fully investigate and record this monument prior to its removal. The archaeological works will be carried out to the professional standards laid down by the Institute of Field Archaeologists. 1.2 Location and Topography The extensive existing quarry (centred at NGR ST 2271 8913) is situated off the A468 Newport/Caerphilly road between Machen and Lower Machen. The quarry is situated on the southwest facing slopes of Mynydd Machen and set between a landscape of planted woodland and pasture to the northwest and farmed pastureland on the southeast. The direction of quarrying is to the northeast, heading into the rising hillside, from about 90m Ordnance Datum (OD) near the valley bottom of the River Rhymney to a local high point, a ridgeway at 279m OD, on the southeast slope of Mynydd Machen. From this ridge, the ground falls northeast to another valley and the village of Pontymister. The area of the proposed extension is to the northeast of the current quarry (Tuck 2004). 1.3 Geology The uncultivated slopes of Mynydd Machen are of rough grassland and bracken with strewn boulders of Millstone Grit. Distinctive scars and spoil heaps from earlier small-scale quarrying are visible over the ridge on the northeast boundary of the quarry. Ordnance Survey mapping of 1885 depicts the earlier beginnings of mineral extraction in a small quarry in woodland named The Park, located adjacent to the Caerphilly branch of the Brecon and Merthyr Railway. These earlier workings are now part of the Hanson Aggregates quarry. Limestone quarried for commercial purposes has already been extracted from an area of around 1.1km by 0.25km. The underlying bedrock is Dolomitic Limestone (Tuck 2004).

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Area of Figure 2

GRID N Based on the 2005 Ordnance Survey 1:25000 Explorer 152 map with the permission of The Controller of Her Majesty’s Stationery Office, © Crown Copyright, Glamorgan-Gwent Archaeological Trust Ltd, Licence number Al10005976

0

1.00 Figure 1. Site location 4

2.00

3.00km


1.4 Historical and archaeological background Human activity in the area is first evident in the archaeological record in the form of round barrows which are typical of Bronze Age funerary customs and by a number of artefacts, notably axes. Two extant Bronze Age barrow sites have Scheduled Ancient Monument status (SAM), Begwns Round Barrow (00012m/MM071) on Mynydd Machen and Twyn Pant-Teg Round Barrow (00027g/MM065) both situated on a local high spot to the southeast of the quarry. Cropmarks identified on aerial photographs suggest two further round barrows may also have existed in close proximity to Twyn Pant-Teg. There is no obvious reason why these sites were chosen and the fields of the proposed extension would seem equally suitable for remains of similar structures, being on the flatter ground of the higher part of the ridge. No evidence of Iron Age activity has come to light within the assessment area. The Roman period probably represents the first signs of settlement and industrialisation in the area with some evidence for mining or surface extraction of the minerals, lead and ironstone. At Draethen, just across the Rhymney valley, several Roman coins were found in an old lead mine. At Lower Machen, Roman finds of masonry structures, carved stonework and metalworking debris were discovered during construction of the A468 bypass road. More recently in the 1990s numerous Roman artefacts from the fields to the south of the bypass road were recovered by metal detecting and fieldwalking (Evans 2004). Furthermore, a geophysical survey of the same fields (Barker and Mercer 2000) revealed a series of features one of which may be interpreted as a timber building. The north side of the road has also revealed remains dating to the Roman period but this area has been less well studied. The archaeological evidence suggests that a fairly densely occupied Roman lead-working settlement of 1st to 2ndcentury date was located within the present village of Lower Machen (Evans 2004). Three distinct areas of early medieval and medieval presence are noted on the hill slopes surrounding the proposed quarry extension. They include Pontymister, where place name evidence points to an early medieval monastic site (Pierce 2000, 135-7); it is documented in the later medieval period as a grange of Llantarnam Abbey. A second area includes Castell Meredydd (SAM MM186, ID 00028g) was a house situated atop a rocky outcrop commanding the Rhymney valley formerly occupied by the Welsh lord Meredydd Gethin. Fortified in the late 12th century, the building was later captured by Gilbert de Clare in 1236 (Newman 2000, 372); the site is now nearly destroyed. The third area of interest is a series of house platforms, probably representative of deserted rural settlement located around the northwest-facing slope of Mynydd Machen. The majority of these belong to the medieval/post medieval periods, but absolute dating is problematic (Locock 2001). These sub-rectangular platforms, of varying dimensions (from between 15m by 8m to 6m by 3m) are formed by a cut and fill process, where the material excavated from the upper part of the hillside is then spread and banked-up over the downslope side to leave a horizontal flat platform. Apart from other types of building construction there appears to be a tradition of platform building in the medieval and later periods in South Wales (Locock 2001). The historical periods of post-medieval and modern are represented by features linked to the present communities in the valleys on either side of the hill, Machen and Lower Machen to the southwest and Pontymister to the northeast. In the main, the landscape of the earlier postmedieval period was dominated largely by rural farming until the 19th century when modern industry developed along the river valleys. Extant chapels and disused mines, limekilns, foundries and tram/railroads are testament to the once prosperous days of industry. Whilst housing proliferated along the valley bottoms, a core area of rural farmland was maintained on the hillslopes. Three sites have Listed Building status, Machen House, Panteg Farmhouse and 5


a bee bole at Plas Machen. Ordnance Survey cartographic evidence from 1886 onward to the present day depicts the proposed extension area as cultivated fields with no buildings shown. A recent watching brief undertaken as part of the ongoing works at the site was conducted during the excavation of a series of sixteen test pits within the extension area (Tuck 2004). No archaeologically important deposits or features were noted in the test pits. However, a walkover survey noted a sub-rectangular feature (MQ1) on the summit of the hill (see Figure 2), which is the subject of the present evaluation. It measures 25m east-west by 20m northsouth, and is delimited by low banks at the northern and eastern edges, and by shallow ditches to the west and south. A further two features were noted (MQ2 and MQ3), both sub-circular in shape and associated with nearby linear-shaped depressions. These may represent demolished cairns or be associated with industrial workings, such as lead mining.

6


2. Methodology Five trenches were mechanically excavated by a tracked excavator with a 2m wide grading bucket. Mechanical excavation was halted when archaeological deposits or the natural bedrock was encountered and hand excavation implemented. A full written, drawn and photographic record was made of all archaeological contexts, in accordance with the GGAT Manual of Excavation Recording Techniques. Contexts were recorded using a single continuous numbering system, and are summarised in Appendix I. All significant contexts were photographed using a Fuji Film S9600 9MP digital camera and in monochrome 35mm film. All classes of finds were identified and catalogued in line with the requirements of the Institute of Field Archaeologists’ Standard and Guidance for the collection, documentation, conservation and research of archaeological materials (2001). The finds recovered were of modern date therefore an on-site recording and discard policy for this class of finds was adopted in line with the GGAT Manual of Excavation Recording Techniques. The management of environmental recording and sampling followed the principles and tenets laid down in English Heritage’s Guidelines for Environmental Archaeology, published in 2002. All deposits with a high potential for the preservation of palaeoenvironmental material were sampled by bulk for subsequent analysis. An archive of records relating to the preparation of the reports has been prepared to the specifications in Management of Archaeological Projects (English Heritage, 1991) Appendix 6 and UKIC’s Archaeological Archives: a guide to best practice in creation, compilation, transfer and curation 2007. After an appropriate period has elapsed, copies of the report and archive index will be deposited with the regional Historic Environment Record (HER). A copy of the report and archive index will also be deposited with the National Monuments Record, RCAHMW, Aberystwyth.

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T2

Section (see Figure 4)

MQ1

T4 T5

Section (see Figure 3)

0

MQ1 T2 T4 T5 T1

T3

See enlargement top right

GRID N

0

100

200metres Figure 2. Plan showing location of Trenches 1-5 and MQ1. Inset showing location of section drawings in Trenches 1 and 2 8

T3

T1

30

60metres


3. Results Trench 1 (Plates 1-4, Figure 4) Trench 1 was excavated to a maximum depth of 1.3m and measured 7.3m in length and 3.8m in width. The basal deposit encountered was limestone bedrock (103). This bedrock was dipping to the south west at approximately 17o. It was encountered at its shallowest point at ground level where it outcropped to the surface and was deepest at 0.6m below ground level. It was fractured on its surface with pieces of the limestone being held in the overlying deposit. Overlying the bedrock was an orange-brown silty clay subsoil (102) containing angular and sub-angular limestone especially concentrated toward the base of the deposit where it had fractured from the bedrock. The subsoil also contained occasional manganese staining. Overlying deposit 102 in a small part of the east facing section was a very thin deposit of limestone fragments (105) varying in size between 0.02-0.12m in length. The deposit measured 1.5m in length and had a maximum depth of 0.10m. Overlying these stones was a deposit of orange-brown silty clay (106). This deposit measured 1.5m in length and only occurred overlying 105. This silty clay deposit 106 separated the thin stone deposit 105 from the clearance cairn proper (104). A mid brown, clay loam topsoil (101) overlay 106. The topsoil contained inclusions of angular and sub-angular limestone and quartz conglomerate varying in size from 0.04m – 0.47m. Contained by topsoil 101 was a clearance cairn (104) which was comprised of limestone and quartz conglomerate boulders measuring up to 0.44m. Trench 2 (Plate 5 and 6, Figure 5) Trench 2 was excavated to a maximum depth of 1.2m and measured 7.2m in length and 4.1m in width. The basal deposit encountered was limestone bedrock (205). This was encountered at varying depths along the trench, the highest being at 0.3m below ground level and the lowest was at 1.2m below ground level. Overlying this bedrock was a red-brown silty subsoil (202) which measured between 0.19m and 0.88m in depth, being deepest where the underlying bedrock was lowest. Overlying 202 was a thin deposit (0.07 – 0.22m) of yellow-white clay (203) which contained frequent small (2mm – 61mm) inclusions of angular and sub-angular quartz. This was only visible in the south facing section. Overlying 202 in part of the west facing section was a deposit of angular and sub-angular limestone (204) varying in size between 0.03 – 0.1m. Directly above this deposit was a significant depth of disturbing root action. The length of the deposit as seen in the section was 1.84m and a minimum depth of 0.17m and a maximum depth of 0.32m. Overlying 204 was a mid brown clay loam topsoil (201). This varied in depth between 0.20m and 0.40m. Contained by the topsoil was a post-medieval/ modern clearance cairn (206), which comprised large sub-angular fragments of limestone and quartz conglomerate.

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Trench 3 (Plate 7) Trench 3 was excavated to a maximum depth of 1.0m and measured 3.7m in length and 1.9m in width. The basal deposit encountered in Trench 3 was the limestone bedrock (303). This was encountered at varying depths along the trench, the highest being at 0.5m below ground level and the lowest part was at 1.0m below ground level. Overlying this bedrock was a red-brown silty subsoil (302) which measured between 0.30m and 0.74m in depth, being deepest where the underlying bedrock was lowest. The subsoil contained inclusions of sub-angular quartz conglomerate and limestone up to 0.17m in diameter. This deposit also contained isolated small flecks of charcoal (2mm in length). Contained by 302 were three small deposits of yellow-brown silty clay (304, 305, 306) having a maximum diameter of 0.12m and a minimum diameter of 0.07m and each measured 0.04m in depth. Each feature was investigated by box section and discerned to be natural variations in the subsoil as no distinct cut could be seen in each case. Two flint finds were recovered and retained from deposit 302 and are subject to a specialist report (see 3.2.1 below). Overlying 302 was a mid brown clay loam topsoil which contained moderate inclusions of sub-angular and sub-rounded limestone and quartz conglomerate fragments varying in size between 0.01m and 0.15m. Contained by topsoil 301 was a post-medieval or modern clearance cairn (307), which comprised sub-rounded and subangular limestone and quartz conglomerate stones which varied in size between 0.14 – 0.70m in diameter. The stones were loosely compacted, with the lowermost stones being held within the topsoil and the upper stones resting upon the stones below. Trench 4 (Plate 8 and 9) Trench 4 was excavated to a maximum depth of 1.0m and measured 4.5m in length and 2.1m in width. The basal deposit encountered in Trench 4 was the limestone bedrock (404). This was encountered at varying depths along the trench, the highest being at ground level and the lowest was at 1.0m below ground level. Overlying the bedrock was an orange-brown silty clay (402) with occasional angular and sub-angular limestone, occurring most commonly where the bedrock was highest. Flecks of charcoal (2mm) were found in isolation in the south end of the trench, contained within 402. The uppermost deposit in Trench 4 was a mid brown, clay loam topsoil (401) varying in depth between 0.28 – 0.52m. This topsoil deposit produced a single flint find that was retained and formed part of a specialist report (see 3.2.1 below). The bedrock outcrops in the north-east corner of the trench where a possible ridge of the bedrock continues in an east-west alignment. Contained within the topsoil was a late post-medieval or modern clearance cairn (403) comprised of angular and sub-angular limestone varying in size from 0.14 – 0.64m. Underlying the stones were numerous fragments of barbed wire and nonbarbed wire fencing.

10


Trench 5 (Plate 10) Trench 5 was excavated to a maximum depth of 1.0m and measured 4.5m in length and 2.1m in width. The basal deposit encountered in Trench 5 was limestone bedrock (503), which was encountered at a maximum depth of 0.3m. The bedrock also outcropped to the surface. Overlying the bedrock was deposit 502, a red-brown silty clay containing frequent inclusions of sub-rounded and sub-angular limestone. Overlying 502 was deposit 503, this was a mid brown, clay loam topsoil containing frequent components of sub-angular and sub-rounded limestone and quartz conglomerate varying in size between 0.04 – 0.47m in length.

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South

North ( 104 )

101

101

101 101

101

106

267.78m

Stone Deposit 105

Site Datum

102

102

0

1.00

Figure 3. East facing section in Trench 1

12

Upper surface of 103

2.00metres


North

South-west

East ( 206 )

201

201

268.45m

201

201

Site Datum

202

202

Upper surface of 205

South-west corner of trench 0

1.00

2.00metres

Figure 4. North and east facing section in Trench 2

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Plate 1. Trench 1. Showing clearance cairn 104. View to the south west.

Plate 2. Trench 1. North facing section showing proximity of the limestone bedrock to the ground surface.

14


Plate 3. Trench 1. South facing section showing proximity of the bedrock to the ground surface.

Plate 4. Trench 1. Oblique view of the west facing section showing the shallow bedrock.

15


Plate 5. Trench 2. Showing stony clay 203. View to north

Plate 6. Trench 2. South-west corner showing clearance cairn (206). View to south-west.

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Plate 7. Trench 3. South-facing section showing clearance cairn (307). Oblique view to north west.

Plate 8. Trench 4. View to the north showing clearance cairn 403 and shallow bedrock 404.

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Plate 9. Trench 4. View to the east showing very shallow and outcropping bedrock 404. The possible leading face of a small quarry area continuing to the east.

Plate 10. Trench 5. View to the south-east. showing shallow and outcropping bedrock.

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3.1 Finds Several finds were encountered during the evaluation and retained. The assemblage contained four flints, a single piece of lead slag and two very small pieces of possibly heated clay (502). The lithics were sent for specialist analysis and the report is included below (3.1.1). 3.1.1 Lithic Analysis (By Richard Lewis BA MIfA) Introduction An area of outcropping limestone bedrock at Machen quarry has been evaluated ahead of limestone extraction. During the excavation of several trenches lithic material from three contexts was recovered and presented for analysis (see Table 1). The analysis of this small assemblage forms the subject of the present report. Methodology The assemblage is composed of flint and was examined and recorded using a typological recording system (Andrefsky 2000). Brief details including raw materials, condition and pertinent technological information was also recorded. No further technical analysis was undertaken. However, the potential for usewear was recorded where it was found to facilitate further analysis in the future. Raw material and condition There is wide variation as to what is commonly classified as flint or chert (Whittaker 2007, 70). However, the most common definition limits flint to material formed in chalk deposits while chert can be found forming in limestone environments. Both materials belong to the cryptocrystalline group of silicates. All of the material examined from the present assemblage can be classified as flint. The patinated conchoidal flint blade (context 401) and undiagnostic conchoidal flint flake (unstratisfied) shows evidence of heat treatment. This may indicate an inferior parent material, which needed improving. Cryptocrystalline silicates when heated slowly to 230-260° Celsius form smooth, glossy surfaces with a soapy feel that become very easy to fracture and thus easier to manipulate. There are several schools of thought as to why this occurs, some suggest the silica crystals melt and fuse becoming more homogeneous while the others argue that microscopic cracks are formed during the heating process that weakens the material sufficiently for easier fracturing (Whittaker 2007, 72-73). Description of material Trench 3 (context 302) produced two flint tools. The first is a Mesolithic conchoidal blade of pale, almost translucent, light brown flint with a small amount of cortex present on the dorsal surface at the distal end. The proximal end of the blade has a clearly defined bulb of percussion and eraillure facet with evidence of a crushed platform. The ventral surface shows possible usewear damage along the blade edge. The second worked piece of flint is a grey patinated scraper fragment with a rounded hinge step at the distal end and retouch on the dorsal surface. Only the distal end of the scraper survives, the proximal end is absent, probably the result of a natural medial break. Trench 4 (context 401) produced a Neolithic conchoidal blade of smooth dark grey flint with mottled white patination, possibly indicating heat treatment. The blade has a prepared platform 19


at the proximal end with a clearly defined bulb of percussion and eraillure facet. The platform is clean (not crushed) and is angled at 35° towards the ventral surface creating an ideal striking platform for its removal from the parent core. The dorsal surface has a clearly defined ridge from previous blade removals and a small quantity of cortex at the distal end. Possible usewear is present on the ventral surface along the upper half of the blade, terminating at an older step fracture. Unstratisfied material included one undiagnostic conchoidal flint flake (possibly debitage). The flake is a smooth dark grey flint with mottled white patination, possibly indicating heat treatment. Clean breaks can be found on two edges, the shorter possibly a prepared platform the longer probably through natural processes. The flake has similar attributes (smooth dark grey flint with mottled white patination) to the flint blade from context 401 and may have a common origin. Discussion The small assemblage is typical of those found in an upland environment and probably the result of casual loss rather than representing evidence of settlement and occupation. However, the presence of at least two pieces of flint, one blade (context 401) and one piece of probable debitage (unstratisfied), showing evidence of heat treatment, suggests that this may have occurred in the immediate locale and that these pieces may have a common origin. Heat treating flint is a hazardous technique, if heated too quickly or exposed to cool air whilst hot they are liable to fracture or shatter but if carried out correctly indicates considerable technical ability. The presence of the Mesolithic blade represents activity of the period. The possible usewear along the ventral surface (along the one edge) indicates that this piece may have been hafted along one edge, as found on tools such as arrows, sickles and knives. However, no resinous residue was visible along the potentially hafted blade edge and the piece was not subjected to microscopic analysis.

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Machen Quarry Extension, Newport: archaeological field evaluation

Table 1: Summary of flint assemblage from Machen Quarry. Site no.633 Trench Context Worked Flakes Retouched Cores and Chips stone forms core fragments Trench 302 1 3

Period

Summary

Total

Mesolithic

Mesolithic conchoidal blade with possible marginal retouch on the ventral surface. However, this may be the result of usewear. Blade is sub-rectangular in form. Proximal end has a clearly defined bulb of percussion and eraillure facet; evidence of a crushed platform. Cortex is present on the dorsal surface at the distal end. Pale light brown flint. Weight = 0.2g, Length = 17mm, Width = 7mm (distal end), 8mm (proximal end). Scraper fragment hinged at distal end, clean medial break, proximal end absent. Retouch present on dorsal surface and ripple marks present on ventral surface. Radial fissures present from proximal end on dorsal surface. Grey patinated flint. Weight = 2.4g, Length = 18mm, Width = 29mm, Thickness = 4mm. Patinated conchoidal flint blade. Prepared platform at proximal end with clearly defined bulb of percussion and eraillure facet. Possible usewear on ventral surface along upper half of the blade, terminating at an older step fracture. Dorsal surface has a clearly defined ridge from previous blade removal and a small quantity of cortex at the distal end. Smooth dark grey flint with mottled white patination, possibly indicating heat treatment. Weight – 7.6g, Length = 66mm. Width = 32mm (distal end), 8mm (proximal end), overall thickness 12mm. Undiagnostic conchoidal flint flake (debitage). Limited ripple marks present. Smooth dark grey flint with mottled white patination, possibly indicating heat treatment. Clean breaks found on two edges, the shorter possibly a prepared platform. Parent material appears synonymous with the flint blade from Context 401. Weight = 4.7g, Length = 38mm, Width = 26mm, Thickness = 3mm.

1

Trench 3

302

-

-

1

-

-

Prehistoric

Trench 4

401

-

-

1

-

-

Neolithic

-

Unstratisfied

-

1

-

-

-

Prehistoric

TOTAL

1

1

1

4

21


Use-wear

Cortex

Ventral View

Dorsal View

Use-wear

Cortex

Dorsal View

Ventral View

Key Extent of striking platform

Presence and position of intact striking platform/bulb of percussion

Extent of whitened thermal effect (shown as grey)

Figure 5. Flint blade (scale 1:1) and Mesolithic flint (scale 2:1) below

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4. Conclusion The results of the evaluation concluded that the stone deposits to the north of the quarry at Machen were clearance cairns of late post-medieval or modern date (MQ1). The stone was held exclusively in the topsoil or resting on top of the turf. Underlying the cleared stones in Trench 4 were several pieces of barbed wire and non-barbed wire fencing. The bedrock underlaying the evaluation area was encountered at shallow depths beneath current ground level. The deepest it was encountered was at 1.2m in Trench 2 where it was unusually deep when compared to the other trenches, where an average depth of 0.3m was common. The bedrock outcropped to surface extensively in the vicinity and this is the likely source of the stone that has formed the clearance cairns. The area both surrounding and including the evaluation area was ploughed during the twentieth century up until modern times. Prior to this ploughing the outcropping bedrock and loose limestone fragments would have been cleared in advance of ploughing to avoid damage to the plough. The subsoil in Trenches 2 and 3 contained worked flints. The small assemblage was typical of those found in an upland environment and probably the result of casual loss rather than representing evidence of settlement or occupation. No further archaeological finds, features or deposits were encountered.

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Bibliography Andrefsky, W, 2000, Lithics – Macroscopic Approaches to Analysis. Cambridge Manuals in Archaeology, Cambridge University Press Evans, E M, 2004, Land adjacent to The Old Post Office, Lower Machen: archaeological field evaluation, GGAT report no. 2004/005 Dunning, R, 2006, Machen Quarry Extension: Written Scheme of Investigation. GGAT Report 2006/072 Locock, M, 2001, GGAT 65 Deserted Rural Settlements in Glamorgan and Gwent: a condition survey, GGAT Report No. 2001/016 Newman J, 2000, The Buildings of Wales- Gwent/Monmouthshire, University of Wales Press Pierce, G O, 2000, The Welsh mystwyr, Nomina 23, 121-140 Tuck, M, 2004, Machen Quarry Extension, Caerphilly: archaeological assessment, GGAT Report no. 2004/040 Whittaker, JC, 2007, Flint Knapping - Making and Understanding Stone Tools. University of Texas

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Appendix I: Context Inventory Context Location Number

Context Context Description Type

101

Trench 1

Deposit

A mid brown clay loam with inclusions 0 - 0.18 of angular and sub-angular limestone and quartz conglomerates fragments varying in size from 0.04 – 0.47m. These are likely to be a result of clearance prior/during ploughing throughout the 19th/20th century. In places the underlying limestone bedrock outcrops to the surface. The depth of the topsoil varies as the subsoil beneath gently undulates.

Post-medieval/ Modern

102

Trench 1

Deposit

An orange-brown, silty clay deposit 0.18 - 0.49 overlying the undulating limestone bedrock. This deposit contains a moderate amount of limestone, especially towards the base of the deposit where the bedrock has fractured. In places the bedrock cuts through this deposit where it outcrops to the surface. Occasional manganese staining contained within deposit.

Unknown

103

Trench 1

Bedrock Natural limestone bedrock.

104

Trench 1

Deposit

A clearance cairn measuring 1.8m in 0 – 0.70 length and a max of 0.8m in depth viewed in the east facing section of Trench 1. The stone includes both limestone and quartz conglomerates varying in size from 0.04 – 0.23m.

Post-medieval

105

Trench 1

Deposit

A thin deposit of small limestone 0.70 – 0.80 fragments (0.02 – 0.12m) measuring approximately 1.5m in length running north-south as seen in the east facing section.

Unknown

106

Trench 1

Deposit

A thin deposit of orange-brown silty 0.30 – 0.60 clay underlying 105.

Natural

201

Trench 2

Deposit

A mid brown clay loam with 0 – 0.20 occasional sub-angular and sub-circular limestone with a maximum diameter of 0.17m


202

Trench 2

Deposit

A red-brown, silty subsoil containing 0.20 – 0.75 isolated patches of large, sub-angular quartz conglomerate and limestone fragments varying in size from 0.09 – 0.40m. Isolated flecks of manganese.

Unknown

25

Depth below Period ground surface (m)

0.49 – n.b.

Natural


Context Location Number



203

Trench 2

Deposit

A thin deposit of yellow-white greasy 0.29 - 0.41 silty clay with frequent fragments of angular quartz .

Unknown

204

Trench 2

Deposit

A deposit of angular and sub-angular 0 - 0.24 limestone varying in size between 0.03 – 0.1m. The deposit had a length in the section of 1.84m and a minimum depth of 0.17m and a maximum depth of 0.32m

Unknown

205

Trench 2

Deposit

Natural limestone bedrock.

Natural

206

Trench 2

Natural

A clearance cairn measuring 2.45m 0 – 0.85m min. (extends into section) in length and a max of 0.85m in depth viewed in the north facing and east facing section of Trench 2. The stone includes both limestone and quartz conglomerates varying in size from 0.11 – 0.55m.


301

Trench 3

Deposit

A mid brown clay loam topsoil which 0 – 0.28 contains moderate amounts of subangular and sub-rounded limestone and quartz conglomerate stones which vary in size between 0.01 – 0.15m. This deposit varies in depth across the trench as the deposits fill undulations in the underlying deposit.

Post-medieval/ Moden

302

Trench 3

Deposit

A red-brown silty clay sub-soil that 0.28 – 0.58 contains isolated sub-angular quartz conglomerates measuring up to 0.17m in size. This deposit also contains isolated small flecks of charcoal. This deposit varies in depth as the underlying bedrock undulates.

Unknown

303

Trench 3

Bedrock Natural limestone bedrock

304

Trench 3

Deposit

0.40 – n.b.

0.58 – n.b.

A sub-circular deposit of yellow- 0.48 – 0.52 brown, silty clay which is extremely fine and greasy. On initial inspection this was thought to be a small feature, possibly a stake hole. However a box section revealed that this deposit was not contained by a discernable cut and probably represented a natural variation in the subsoil.

26

Natural Unknown


Context Location Number


305

Trench 3

Deposit

A sub-circular deposit of yellow- 0.47 – 0.51 brown, silty clay which is extremely fine and greasy. On initial inspection this was thought to be a small feature, possibly a stake hole. However a box section revealed that this deposit was not contained by a discernable cut and probably represented a natural variation in the subsoil.

Unknown

306

Trench 3

Deposit

A collection of at least three sub-oval 0.50 – n.b.. patches of yellow-brown fine, greasy silty clay. All natural variations in 302.

Natural

307

Trench 3

Deposit

A large clearance cairn built out of sub- 0 – 0.80 rounded and sub-angular limestone and quartz conglomerate boulders which vary in size between 0.04 to 0.7m. The boulders are loosely compacted and contained by a loose clay loam, very similar to the topsoil. Lower boulders have sunk into the underlying subsoil through the weight of the stones piled above.


401

Trench 4

Deposit

A mid brown clay loam topsoil 0 – 0.28 containing a moderate abundance of angular and sub-angular limestone. The bedrock outcrops in the northeast corner of this trench where the ridge of a small quarry may be seen. Contains clearance cairn 403.

Post-medieval /Modern

402

Trench 4

Deposit

An orange-brown, silty clay deposit 0.28 – 0.53 with occasional abundance of angular and sub-angular stone where the bedrock is high. Tiny (2mm-4mm) flecks of charcoal found in isolation to the south end of the trench. A single flint recovered from this deposit.

Unknown

403

Trench 4

Deposit

A late post-medieval or modern 0 – 0.56. clearance cairn. The stone is deposited on top of barbed wire fencing and other metal fencing wire. The stone is angular and sub-angular limestone measuring between 0.14 – 0.64m and contained within the topsoil.


404

Trench 4

Natural

Natural limestone bedrock

Natural

27


0.56 – n.b.


501

Trench 5

Deposit

A mid brown, clay loam topsoil with 0 – 0.21. frequent inclusions of sub-angular and sub-rounded limestone and quartz conglomerate. The stone varies in size between 0.004m and 0.47m in length. These deposits of stone most probably represent post-medieval clearance. The topsoil is punctuated in places by outcropping bedrock.


502

Trench 5

Deposit

A red-brown silty clay containing 0.21 – 0.34 frequent sub-rounded and sub-angular limestone measuring up to 0.29m. The natural bedrock outcrops through this deposit. The subsoil also contained flecks of manganese.

Unknown

503

Trench 5

Bedrock Natural limestone bedrock

n.b. – not bottomed

28

0.34 – n.b.

Natural

Machen Quarry extension, Carphilly

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