NHER 5640 (Monument) - Grimes Graves Neolithic flint mine and Grimshoe Mound

Neolithic flint mines with later occupation.
Includes Grimshoe, possible tumulus or dump of debris, later hundred court.
Former scheduled monument 70 now included within scheduled area 66.

1852. Excavation revealed animal bones.

1868-70. Excavation of one shaft and Grimshoe.
See 1870 publication
See also web article (S46) detailing research on contemporary press coverage.

1914-1939. 25 years continuing excavation of flint mines and Grimshoe. (S23).
1950s. Surface finds Neolithic flint.
1971-5. Excavation of mine shafts. (S1)
1976. Excavation of a mine shaft.
1977. Casual find Neolithic axe.
1983. Observation of cutting of pipe trench (S24, S25 and S26).
1984. Excavation round top of a shaft.
Before 1989. Bronze Age/Iron Age sherd found.
Detailed reports, photographs, press cuttings, extensive bibliography in file.

EVIDENCE FOR EARLIER PREHISTORIC ACTIVITY

Palaeolithic finds:

Although the bulk of the material recovered at Grimes Graves is of Neolithic date, a small number of earlier finds have also been found. These include 2 Palaeolithic handaxes listed by (S11) as being held by the Cambridge University Museum of Archaeology and Anthropology (CUMAA). These are probably two objects listed in the museum's current records as '?Palaeolithic handaxes', both of which are recorded as being from "Weeting, Grimes Graves" (1926.941; Z 29515). One of these objects is described in (S30) as a "…very genuine-looking handaxe in the Acheulian manner…". The CUMAA also holds an object recorded as a large Lower Palaeolithic "disc" that had been recovered at Grimes Graves by Rev. W. Gray (1924.1038/Record 2). According to (S11) there is also much extant material of doubtful age that has been claimed as Palaeolithic but most likely relates to later flint mining activities.

A handaxe from Grimes Graves is also described and figured in (S12). It would appear that this implement was a large bout coupé - a form of handaxe typically associated with Late Middle Palaeolithic activity. This handaxe is listed as potentially Middle Palaeolithic in (S30) and (S31). Although it is noted in (S31) that it appears to be a genuine bout coupé it was felt that there were some lingering doubts over the age of the object (given that Neolithic "celts" are also discussed in the same article). The present location of this implement is unknown.

Another potentially Middle Palaeolithic handaxe was recovered at Grimes Graves during the 1972-1976 British Museum excavation; this object being found within the deposits associated with the silting up of Shaft X (S19). This handaxe is also of a cordate form usually associated with the Middle Palaeolithic. It falls within the range of variation exhibited by the Middle Palaeolithic handaxes found recently at nearby Lynford Quarry (NHER 37095) and it is possible that the Grimes Grave handaxe originated at this site, perhaps having been picked up as a curiousity during the Late Neolithic (S19).

Other potentially Palaeolithic finds from this site include a ovate implement made form a Levallois flake. This object was identified in the British Museum's Sturge Collection by J. J. Wymer and is noted on (S29) (although it was not included in S19)). The British Museum's records also suggest it holds several other Palaeolithic objects from Grimes Graves, although whether these objects would still be regarded as such is unclear. These flints include 2 cores that were previously held by the Geological Museum (1989,0301,1199-1200) and a possible handaxe (2011,8050.7).

In (S19) Wymer also lists a number of Palaeolithic handaxes in various museums that appear to have been found close to Grimes Graves. There is however no evidence that these objects were found in the immediate vicinity of the flint mines; it being more likely that they were recovered in or near the Botany Bay clay pit (see NHER 5643 for further details).

A number of the Palaeolithic finds from this site are noted in (S32) and (S33).

Evidence for Upper Palaeolithic and Mesolithic activity:

Although it is clear that sustained activity did not begin on the site until the Neolithic there is now limited evidence for at least a degree of activity during the preceeding Late Upper Palaeolithic and Mesolithic periods. Late Upper Palaeolithic flints have now been identified in several museum collections that are recorded as being from Grimes Graves, including a blade in the Diss Museum (T.820) and another blade in the British Museum's Armstong Collection. These objects are described in (S27) and are amongst the four blades listed in (S28) as being from Weeting or Lynford. The Cambridge University Museum of Archaeology and Anthropology also holds an earlier prehistoric core from Grimes Graves (Z.15457). This piece is listed in (S22) and recorded as Upper Palaeolithic in (S27). The British Museum's Sturge Collection also includes a Late Upper Palaeolithic flint blade that is recorded as having been found near Grimes Graves (see NHER 5590).

A small number of Mesolithic flints were found during the 1971-2 excavations, including two micro-cores and two microliths (S21). The microliths are noted in (S22) and were found on an old land surface, in association with a Late Neolithic flint industry. As noted by (S21) the presence of these distinctive Mesolithic pieces raises the possibility that other, less diagnostic pieces in the collection were also of this date. Further evidence for Mesolithic activity was uncovered during the British Museum's 1972-1976 excavations in the West Field. Two small features, both of which contained hearth debris, produced radiocarbon results that pointed towards activity on the site during the seventh or eight millenium BC (S18). The first was a small hearth (Cutting 880/910 F1 6640-6250 calibrated years BC at 95% probabability) and the second was a small pit (Cutting 900/970 F5 8300-6600 calibrated years BC at 95% probabability). It should however be noted that these results were obtained over 30 years ago and it is possible that the accuracy of these dates was overestimated. See (S18) for full details.
P. Watkins (HES) 29 May 2013.

RECENT EVENTS

1992. Geophysical Survey.
Magnetometer survey of area of proposed extension to the Grimes Graves car park.
Although the conditions for survey proved not to be ideal the results suggested that major features are probably not present.
See report (S40) for further details.
P. Watkins (HES), 8 March 2017.

1995. Analytical Earthwork Survey.
Survey by Royal Commission as part of a national project investigating Neolithic flint mines.
A total of 433 possible shafts were recorded, nearly 70 more than had been identified previously. Many of the additions were relatively shallow, suggesting that at least some may have been working platforms rather than true shafts.
See publication (S41) for further details. The results of this survey are also noted in (S42).
P. Watkins (HES), 20 March 2017.

2002. Laser scan.
Detailed 3D laser scan of interior of Greenwell's Pit undertaken.
This survey is noted in (S3).
D. Holburn (HES), 7 October 2011.

For material held by Shropshire, Lapworth, Birmingham, Worcester and Stoke on Trent Museums (S2).
J. Allen (NLA), 4 July 2003

2003. Laser scanning.
A second laser scan project has begun in Greenwell's Pit, using different technology to that used in 2002, and designed to increase the levels of accuracy and detail recorded three-dimensionally.
Information from brief summary in (S4).
D. Holburn (HES), 7 October 2011.

2004. Laser scanning.
The underground shaft and network of tunnels known as Greenwell's Pit - part of the Neolithic flint workings - have been laser scanned to record them in high resolution three-dimensional detail, in a world's first application of this technology (work continued from 2003).
Information from brief summary in (S5).
D. Holburn (HES), 28 September 2011.

2005. Laser scanning of underground workings at Greenwell's Pit.
A final season has completed the coverage of the underground workings at Greenwell's Pit to create what may be the world's first 3D virtual reality model of a flint mine. The captured data comprises 835 million measurements. Once fully processed, the new data will form part of a virtual reality 'flyover' of the surface of the site which then proceeds down into the galleries of Greenwell's Pit.
Information from brief summary in (S43).
D. Holburn (HES), 26 September 2011.

October 2006.
Scheduled monument consent granted concerning the taking of samples of flint from shaft fifteen of the flint mine for trave element analysis.
See (S6) for further details.
H. White (NLA), 6 April 2009.

March 2007. Geophysical Survey.
An electrical resistivity survey was carried out over two areas of the site, one to the north and one to the west of the known extent of archaeological features. Preliminary results have noted several roughly circular conductive features in the northeast of the northern area that may represent additional flint shafts. In the western area, two additional circular resistive features were identified. These are located near a known shaft and may represent additional features.
See report (S7) for further details.
H. Hamilton (NLA), 23 January 2008.

November 2007. Geophysical Survey.
Ground penetrating radar survey of two trial areas, the aim of which was to identify suitable targets for investigation and sampling by a powered soil auger. Conditions proved to be particularly suitable for GPS, with a number of suitable targets were identified, including periglacial sand-filled stripes and possible further flint-mining activity. The interpretation of data in the field allowed the auger survey to be conducted in conjunction with the geophysical survey.
See report (S8) for further details.
P. Watkins (HES), 2 February 2020.

2009-2010.
Grimes Graves Environs Project.
Work undertaken as part of this project included documentary research, analysis of finds held by museums, a finds distribution survey and the start of a ground penetrating radar survey.
See NHER 55660 for details of remains observed following tree felling to the south-west of the main site.
Information from brief summary in (S44).
P. Watkins (HES), 23 March 2017.

January 2010. Site visit.
The site visit previously recorded under this number is now recorded under NHER 55660.
H. Hamilton (HES), 01 December 2016.

2011. Residue analysis of chalk 'lamps'.
45 small cup-shaped chalk objects were recovered from previous excavations and were originally interpreted as lamps. Due to the lack of evidence for burning or soot stains this interpretation was controversial, particularly because of the question of whether lamps would have been necessary to illuminate the galleries due to light reflecting off the main shaft. A re-analysis of the cups could not reproduce earlier results, which had lent support to the lamp interpretation. The experimental results indicated that if animal fats had been used that these would have been absorbed into the chalk cups, but this chemical signature was not present in the analysis of the archaeological cups.
See (S10).
S. Howard (HES), 1 November 2011.

2014. Chronological Modelling.
Completion of English Heritage-funded project to precisely date flint extraction and working at Grimes Graves through radiocarbon dating and the application of a Bayesian analysis of the results to the available archives.
See report (S45) for details of all the radiocarbon determinations, along with a series of chronological models that provide a more precise chronology for the site.
P. Watkins (HES), 5 December 2021.

February 2017. 'Brecks from Above' and Breckland National Mapping Programme [1].
The Neolithic flint mines of Grimes Graves, together with related features such as Grimshoe mound, are visible as earthworks on aerial photographs (such as S34-S36), and lidar imagery from a survey flown in 2015 (S37-S38). The pits and depressions in the main area of earthworks have been mapped approximately from the lidar. With the exception of Grimshoe mound, the banks/mounds have not been mapped. Therefore, existing ground surveys should be referred to for detail (the RCHME Survey Report, S39, for example). A number of the outlying pits, most of which were subject to excavation prior to the Second World War, show signs of recent disturbance on 1940s aerial photographs (S34, for example), suggesting that they may have been used as military positions during the war (see NHER 61549). A trapezoidal mound or platform, clearly visible on the aerial photographs taken in February 1946 (S35), and on the lidar survey (S38), at TL 8157 8977, had previously been identified as a modern feature (see Sieveking, et al., 1973, S40). It has been recorded as part of this site, as it is probably a spoil heap from the pre-war excavations (see too S39, p16). Cropmarks noted by Sieveking's survey (S40), and a parchmark of a ring ditch recorded by the RCHME survey (S39, p16), were not identified on the consulted sources. Boundaries and cultivation marks recorded across the site, all of which are presumed to be later than the Neolithic flint mines, have been recorded as NHER 61550. As mentioned above, features relating to Second World War activity have been recorded as NHER 61549.
S. Tremlett (Norfolk Historic Environment Service), 20 February 2017.