‘In the castle called Seresberi’. Old Sarum and a New Survey of the Inner and Outer Baileys

John Constable's watercolour of Old Sarum, showing the scale of the outer ramparts and the Norman motte (source: Wikicommons, http://commons.wikimedia.org/wiki/File:John_Constable_-_Old_Sarum_-_WGA5198.jpg)

John Constable’s watercolour of Old Sarum, showing the scale of the outer ramparts and the Norman motte (source: Wikicommons, http://commons.wikimedia.org/wiki/File:John_Constable_-_Old_Sarum_-_WGA5198.jpg)

Old Sarum in Wiltshire has always proved an emotive archaeological site. The substantial ramparts of the Iron Age hillfort and the medieval motte dominate the skyline on the A345 running north from Salisbury, and has been portrayed by scholars and artists including Stukeley and John Constable. The palimpsest of settlement at the site and in its environs encompasses the Iron Age and Romano-British periods, possible Anglo-Saxon settlement, and the medieval founding of a castle, cathedral and settlement. The site formed part of the rotten borough of Old Sarum, and its strategic position was utilised during the Second World War. The Inner and then Outer Bailey formed the focus of excavations in the first part and middle of the 20th century, first by Hawly , Hope and Montgomerie in the years preceeding the First World War, then by Rahtz in the 1940s and 1950s.

The work of Hawley and Hope commenced with excavation of the Inner Bailey in the earlier seasons. Excavation then extended to the Outer Bailey, with the 1914 season focusing on the Cathedral and Bishop’s Palace. The excavation report indicates the presence of structural remains beyond those currently visible at the site, with a number of the lesser structures having been backfilled. The later work by Rahtz focused on the ramparts of the Outer Bailey and the tunnel running through the northern section of the ramparts. The body of work left from the excavations provides ample evidence of the nature and depth of the archaeological deposits for both the Inner and Outer Baileys, although the focal point of the work was always trained on the more substantial or higher status structures and buildings of the site. Much of the urban plan of the Inner Bailey, including the Palace, the Keep and Postern Tower was revealed, although some scintillating glimpses of structures from earlier periods, including a possible Roman building some 5m below the modern ground surface, were also gained. In the Outer Bailey the excavations revealed considerable structures for the cathedral and Bishop’s Palace, but much of the area in the other three quadrants of the Outer Bailey remain a mystery. On the basis of the known archaeological evidence for the site it was decided that application of topographic and geophysical survey techniques would assist in mapping the buried remains across the remainder of the Outer Bailey, and the unexcavated parts of the Inner Bailey.

To that end staff at the University of Southampton drew up a three year project overview, and were granted permission from English Heritage, to carry out a new survey at the site and in its environs as part of student fieldwork for second and third year modules in archaeological survey and geophysical survey. Results of the survey would form the basis for students to compile their own reports for assessment on the modules.

Geophysical survey in the Outer Bailey with the spire of Salisbury Cathedral visible in the background

Geophysical survey in the Outer Bailey with the spire of Salisbury Cathedral visible in the background

The work of the staff and students this year centred on the area within the ramparts of the hillfort, some 6.5 hectares in size, with topographic survey and earth resistance and magnetometry being conducted in the Outer Bailey, and GPR survey across the Inner Bailey to target areas left unexcavated by Hawley and Hope. Survey was supervised by the author, Timothy Sly, Dominic Barker, Penny Copeland and Scott Chaussee.

Magnetometer survey in the Outer Bailey with the bridge to the Inner Bailey in the background

Magnetometer survey in the Outer Bailey with the bridge to the Inner Bailey in the background

Earth resistance survey in the Outer Bailey

Earth resistance survey in the Outer Bailey

In spite of the mixed success using magnetometry at some sites in Hampshire and Wiltshire, the nature and depth of deposits at Old Sarum meant that the flint core and stone buildings of the Outer Bailey contrast well to the surrounding sediment. In addition the response to the earth resistance survey was also clear. The preliminary results for the Outer Bailey indicate extensive structures across the entire area, with buildings spread out along the curtain wall, particularly in the south-east sector of the site, and the pattern of urban areas visible in the south-west sector.

Detail of the results of the magnetometry from the Outer Bailey

Detail of the results of the magnetometry from the Outer Bailey

Many of the structures from the Hawley and Hope and Rahtz excavations are also present, and new buildings are added to the plan of the north-west sector of the site, including a possible sub-circular structure.

The GPR survey in 2014 focused on the area of the Inner Bailey, utilising a 200MHz antenna, and on targetted areas in the Outer Bailey using a 500MHz antenna. In principle the use of the lower frequency antenna within the Inner Bailey should assist in locating some of the deeply buried structures below the level of medieval buildings mentioned in the literature. Potentially comparison of these results at 5-6m depth should allow a picture of the Iron Age and Roman deposits for the area to be compared with the results from the Outer Bailey.

GPR survey of the Inner Bailey. Many of the excavated structures give a clear indication of the potential depth of some of the deposits, up to c.5m in places. The 200MHz antenna should allow structures to be located down to these depths

GPR survey of the Inner Bailey. Many of the excavated structures give a clear indication of the potential depth of some of the deposits, up to c.5m in places. The 200MHz antenna should allow structures to be located down to these depths

In addition to the high resolution survey work, an Electrical Resistivity Tomography (ERT) profile was run across the site, through the western entrance to the hillfort, skirting the northern side of the motte ditch, and ending close to the ramparts on the north-eastern side of the site. The profile is designed to assess the depth of archaeological sediments across the site, and their relationship to the underlying gravels and chalk.

ERT survey in a profile running across the site

ERT survey in a profile running across the site

There is much work to do for the interpretation of the results, but the correlation between the 20th century excavations and the latest results is telling. The results are allowing the team to expand on the excavation plans, showing the presence and nature of the new structures in all areas of the site, including ranges of buildings on the southern edge of the area of the Cathedral, and a substantial building standing alone in the south-eastern sector of the Outer Bailey. The plan for the next few seasons will be to complete work in the Outer Bailey, and to conduct survey in the environs of Old Sarum. The relationship between the defended site and the Roman road and settlement to the south of the ramparts will provide a focus for research.

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Theban Waterscapes and Harbours Survey THaWS 2014 – Measure for Measure

The current season of THaWS fieldwork has given the team some time for reflection on the survey results from 2012 and 2013, and has provided an opportunity for addressing some of the outstanding issues related to the mapping of Thebes on the west and east banks. Survey work throughout the 2012-2014 has been carried out by the team members, including the project director Angus Graham, who oversees the work with the Egypt Exploration Society (EES; http://www.ees.ac.uk/),  Sarah Jones from the Museum of London (MOLA) and Dominic Barker and the author from the Department of Archaeology at the University of Southampton. In 2012, due to some problems with equipment, much of the surveying in of the geophysical survey areas and profiles was conducted using a total station. In 2013 an RTK GPS was used for surveying topographic points and giving elevation data for the topographic correction of GPR and ERT profiles. While these surveys gave sufficient data for processing and interpreting the results of the geophysics, it still left some largely unanswered questions in the minds of the team. How does the current GPS survey relate to the existing local surveys on the west and east banks at Thebes? What remaining survey markers or stations exist in the landscape, allowing THaWS to tie material in to the current survey? Most importantly perhaps, we returned to the issue of what elevation above sea level to use for the project. THaWS is interested in looking at the increasing levels of Nile sediment over thousands of years, and how the natural and man-made changes to the floodplain relate to the archaeology of the area. Having a standard benchmark or datum for this is crucial.

Assessing the different surveys and coordinate systems utilised around Thebes, using sketches and charts, the Survey of Egypt and Reimer maps and field notes

Assessing the different surveys and coordinate systems utilised around Thebes, using sketches and charts, the Survey of Egypt and Reimer maps and field notes

The first step in relating the different local surveys in the study area was to list and assess the nature of the different coordinate systems and datums utilised by different surveys.

It is good to give a bit of historical background to the mapping in the area. The data that we have relate ostensibly to national mapping programmes, or individual projects utilising local or arbitrary coordinate systems. We also have mapping dating from the 19th century, in the form of sketch maps and plans. Of these the map data that has provided the most relevant data is the map produced by John Gardner Wilkinson (1797-1875). Wilkinson published The Topography of Thebes and General View of Egypt in 1835, describing the monuments and landscape around Thebes. No graticule is present on the map, and no information regarding datum or coordinate system are presented. The map does, however, relate standing archaeological remains with features on the Nile floodplain, and therefore provides a crucial document in building up a picture of the study area.

A detail of Wilkinson’s map

A detail of Wilkinson’s map

The maps that are perhaps most pertinent to the THaWS work are those produced by the Survey Department between 1892 and 1907 for the cadastral mapping of Egypt. Lyon’s 1908 description of the cadastral survey includes some notes on technical aspects of the survey, including the use of metal chains and some of the practicalities of surveying this vast country. The maps based on the Survey of Egypt for Thebes all utilise the Egyptian Red Belt datum and the Survey of Egypt coordinate system. These systems were also adopted by the map produced by Schweinfurth, published by Reimer in Berlin in 1909, and drawing on Wilkinson’s map, the Survey of Egypt cadastral survey.

One of the principal aims of the 2014 survey was to try and locate trig points and bench marks created by the Survey Department for the cadastral mapping of Egypt. Locating the remaining markers is, however, another matter. The reconnaissance in 2013 and this season has found only two markers; one a trig point above El Gorn on the heights above the Valley of the Kings, and a benchmark on the corner of the wall of one of the alabaster shops to the south of Hatshepsut. The lesson from this experience is clear: the survival of even official survey markers in the landscape at Thebes is unlikely.

Survey marker on the heights of Biban el Muluk, one of the only markers in the area of El Gorn where the marker survives

Survey marker on the heights of Biban el Muluk, one of the only markers in the area of El Gorn where the marker survives

Survey benchmark at the alabaster shops to the south of Hatshepsut

Survey benchmark at the alabaster shops to the south of Hatshepsut

 

In addition to the national and regional mapping projects being assessed, many of the local surveys on the east and west banks are of relevance to the project. In particular survey of markers from the Theban Mapping Project (http://www.thebanmappingproject.com/) and markers from the ongoing project work at the temple of Amenhotep III provide useful ancilliary data for the THaWS work. These surveys use their own local coordinate systems, however, the use of reduced heights above sea level for the projects makes the survey of points vital to allow current survey data to be related to existing publications showing the relationship between monuments and the ancient Nile flood levels.

Survey this season with the GPS allowed a transformation to be performed between the UTM 36N coordinate system with WGS84 datum being used by the GPS, and the Theban Mapping Project survey markers. The result of this shows some large error caused by the probably moving of survey markers within the landscape over the last 20-30 years. The systems of these projects give useful elevation information that is germain to the aims of the current THaWS work.

 

Dominic Barker and Kamal Helmy Shared positioning the GPS rover on a survey marker at the temple of Merenptah

Dominic Barker and Kamal Helmy Shared positioning the GPS rover on a survey marker at the temple of Merenptah

One final set of survey data has been essential for resolving the issues surrounding elevation: the survey datum and account of Hölscher for the excavations at Medinet Habu. A datum point, set at 0m, was established by Hölscher on the threshold of the first pylon at Medinet Habu. He wrote:
‘For the leveling of Medinet Habu the threshold of the first pylon was chosen as the zero-point. This point lies 77.09 meters above sea-level. A bench mark of the Survey Department on top of the granite threshold between the two guardhouses of the Eastern Fortified Gate stands at +76.82 meters, that is, 27 centimeters lower than our zero-point of leveling.’

(Hölscher 1934, 3)

Although the Survey Department benchmark is no longer visible, the stones on either side of the central axis at the threshold remain in situ, and provided a useful datum to record with the GPS. In fact when this point is considered together with the other points of elevation on the West Bank there is a discrepancy of 0.12m over points spread some 5km across the landscape, a considerable achievement in terms of the accuracy of the original Survey Department benchmarks and the traversing of these elevations to the different projects concerned. For the THaWS survey we are now in a much better position to use a suitable benchmark for elevation above sea level that relates to the work and published material of the different projects at Thebes.

Kamal Helmy Shared and Dominic Barker surveying on top of the mounds at Birket Habu

Kamal Helmy Shared and Dominic Barker surveying on top of the mounds at Birket Habu

There is still work to do in relating our survey data with work on the West Bank and at Karnak to ensure that THaWS data is compatible with other datasets, in terms of spatial location and elevation. However, the relationship between our geophysical survey and borehole data, our current survey, and its relationship to other survey data at Thebes, is perhaps more transparent and congruent to existing material.

 

References
Hölscher, U. 1934, The Excavation at Medinet Habu. Volume 1 General Plans and Views. The University of Chicago Oriental Institute Publications Volume XXI. Chicago; University of Chicago Press.
Lyons, H.G. 1908, The Cadastral Survey of Egypt 1892-1907. Cairo; National Printing Department.
Wilkinson, J.G. 1835, Topography of Thebes and General View of Egypt, being a Short Account of the Principal Objects Worthy of Notice in the Valley of the Nile. London; John Murray.

 

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Archaeological Survey at Ras Al Hadd, Oman

Over the last few weeks a team from the University of Southampton has been working with a team from the British Museum, surveying the archaeological site at Ras Al Hadd. The focus of the survey work was to carry out a topographic survey of the site, and to conduct magnetometer and GPR survey of areas of the occupation mound, prior to the commencement of excavation of the site. In addition the geophysical survey grid was used as the basis for intensive surface collection across the western portion of the site.

The fort at Ras Al Hadd

The fort at Ras Al Hadd

The Bronze Age and Iron Age archaeology at the site forms a mound on  the coastal plain a few kilometres from the tip of the south-east limits of the Arabian Peninsula. Later settlement has covered most of the site, including a substantial fort and new mosque. The remnants of post-medieval defence overlie the mounds of the later prehistoric settlement, one of a number in the area of the coast. It is the later archaeology that is immediately striking upon visiting Ras Al Hadd. A number of old cannon litter the village, some propped on breeze block plinths, some lying forgotten. Others are located in the fort, and lines of Martini-Henry rifles line the walls of the entrance to the courtyard. In the vicinity of the inlet and lagoon to the west of the site, a solitary tower guards the entrance to the inlet and  the reaches of the lagoon.

The lagoon to the west of Ras Al Hadd

The lagoon to the west of Ras Al Hadd

The focus of the survey was, however, the prehistoric material at Hadd. The survey utilised a number of techniques to map the area. The survey grid was established using RTK GPS, with the instrument also being used to map the topography across the site and the surrounding coastal plain between the mound and lagoon. Surface features were also surveyed in for comparison with the geophysical survey results.

GPS survey under way

GPS survey under way

Phil Riris carrying our magnetometer survey

Phil Riris carrying our magnetometer survey

The site was also surveyed using magnetometry and GPR, focusing on the western and northern parts of the mound,where modern occupation has affected the archaeology the least, and within the interior of the fort. Results of the survey revealed a number of potential archaeological features, including remains of earlier phases of the fort, Iron Age pits, and cairns. In addition to the geophysics, the British Museum team and a team of workmen undertook a systematic surface collection of a part of the surveyed area. The preliminary results show the strength of the methodology incorporating such techniques, with the plot of the fieldwalking overlying on the geophysics, and giving some clear pointers as to the nature of the ancient deposits.

Fieldwalking being carried out along the western side of the mound

Fieldwalking being carried out along the western side of the mound

One of the outcomes of travelling in the area was the opportunity to take a cursory look at the coastal area with a radius of a few kilometres from Hadd. The terrain shows the same plain, covered with thorn scrub and coastal inlets, but with a number of small occupation mounds breaking the topography. Indicating quite a dispersed settlement and use of different sites by the population, from prehistory up until more recent times. An amazing landscapewith hopefully much further scope for work.

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Electrical Resistivity Tomography on the Isola Sacra

Further to my last post, the week before last was spent with a team from the British School at Rome carrying out a single Electrical Resistivity Tomography (ERT) profile across part of the Isola Sacra, designed to complement the magnetometer survey of the area, and recent coring undertaken by Ferreol Salomon.

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The Necropolis di Porto, showing the Via Flavia, between Portus and Ostia Antica. The ERT survey was carried out in an effort to cover the area of the necropolis, ancient road and dune cordon along the Roman coastline, together with the features including a large canal to the east of the necropolis

The profile ran from the westernmost point of the Necropolis di Porto in a north-east direction along one of the principal trackways of the Isola Sacra, along the edge of the fields established by the bonificazione of the area. Levels of readings were taken down to a depth of 7m to match the sediments recorded in Ferreol’s cores. The short field season highlights a useful way of targetting features found in the broader blanket survey of the landscape to aid our understanding of the depth and nature of features located in area datasets. Alice James and Matt Berry from the British School at Rome assisted in the survey on the ground, and are now hard at work processing this data and ERT data from some other projects conducted in the Autumn.

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ERT survey probes running alongside the fencing of the necropolis looking west.

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The profile along the trackway to the east of the necropolis. 180m were covered in total.

A preliminary look at the survey data shows that the tombs of the necropolis are indicated as high resistivity anomalies, although the road surface is not clear – perhaps indicating the robbing out of paving – and a high resistivity surface of material is visible running across the landscape to the east.

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Data collection using the Tigre and laptop. Some battery life issues curtailed the work on the first day, although the heads-up imaging of the data as it is collected is useful in the field.

The data further to the east, in the area of the canal, is more difficult to assess on the basis of a cursory glance. The high resistivity readings near the surface have a double break in them, correlating approximately with the canal width. However, the sandy infilling sediment, and the sandier subsoil in the area, coupled with waterlogging across the survey area, has made visualisation of the canal profile difficult. Further processing and clipping of the data may give a clearer indication of the canal profile, and its relationship to the nectropolis and Via Flavia to the west.

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Contemplating Data Analysis and Narrative

The lengthy period since my last blog post represents a diversion from the usual pattern of fieldwork and rapid turn-around of research reports and has provided some time for reflection on the nature of the types of data we collect as archaeologists and what we do with it. Much of the work of recent months has been related to large-scale research projects, and the analysis and interpetation of varying forms of geophysical and archaeological data to a number of different research agendas. The need for focus for some of the data interpretation really precluded the kind of mindset that allowed for easy blogging over the time, and it was this that prevented any reflection here. Other areas of the data analysis in theory would have provided some good material for an outlet, but it is only arriving at this point, with a little breathing space before moving on to the next datasets, that it seemed prudent to take to the blog.

Several projects have been central to developing these thoughts. In August students and staff from the University of Southampton worked with students from Northwestern University in the USA, under the direction of Professor Matthew Johnson, at Knole Park and Ightham Mote in Kent. The survey was founded on an integrated methodology of topographical and geophysical survey, with the principal aim being provision of field training for undergraduate students at both universities. The nature of this project contrasted sharply with the other areas of work; the assessment and writing up of survey for the Theban Harbours and Waterscapes Survey, under the direction of Dr Angus Graham, and the integration and interpretation of data from the Portus Project, directed by Prof. Simon Keay, for all of the GPR and ERT data collected from the areas of the Imperial Palace and the Severan Warehouses at the site. Although the techniques applied on both projects are similar (GPR, ERT), however, the nature of the datasets reflects the very different questions being asked about the areas. What is apparent from the post-fieldwork integration and analysis of data from all of these projects are the varying levels of interpretation required for the different project agendas, especially in the short to middle term.

Field notebook used at Thebes. The day to day drudgery, graft and bon homie of the fieldwork conducted for the different project contrasts sharply with some of the more reflective moments of the processing and interpretation work akin to all projects. One of the tangible links between the fieldwork and desk-based worlds of the archaeological survey are the field notes; descriptions, ntes on weather conditions and, in the case of geophysical survey, lines of location data associated with thousands of profiles of GPR and ERT data, or to the location of grids in a magnetometer or earth resistance survey.

Field notebook used at Thebes. The day to day drudgery, graft and bon homie of the fieldwork conducted for the different project contrasts sharply with some of the more reflective moments of the processing and interpretation work akin to all projects. One of the tangible links between the fieldwork and desk-based worlds of the archaeological survey are the field notes; descriptions, ntes on weather conditions and, in the case of geophysical survey, lines of location data associated with thousands of profiles of GPR and ERT data, or to the location of grids in a magnetometer or earth resistance survey.

For some fieldwork the principal requirement is for a documentary record of the fieldwork that took place, with a general and sometimes cursory assessment of the survey results. The need for this approach can be the result of different pressures or outcomes of the field season; an interim report for an ongoing field project, mandatory requirements for reporting to overseas authorities, or a primary phase of investigation within a larger project. Having produced dozens of these reports over the years the exercise does prove useful in terms of the process of survey and relating to how the archaeologist forms an overview of the results of the fieldwork. The process allows the broad trends of the different datasets to be established, gives the the most expansive spatial and temporal view of the survey results in terms of the project objectives and provides an opportunity for pleasing imagery of the datasets to be reproduced. The  short report does, however, present limitations. The broad bruch-strokes of cursory data analysis leaves out the details of the data, the smaller anomalies and features, the more controversial questions relating data to the known archaeological record, and the considered and established link between individual anomalies in the dataset, and their description and interpretation in detailed text. The summary analysis of the data is empirical in nature, and there is a risk of interpreting the work in black and white, in terms of research objectives met and archaeological facts maintained or overturned. Without further elucidation these fleeting assertion can become established facts in the mind of the archaeologist, highlighting the need for detailed assessment.

Magnetometer survey data from Knole Park, draped over the topographic surface derived from the GPS survey. The aesthetically pleasing image and the overview of the data all belie the need for a deep and reasoned analysis of what is essentially a high resolution dataset.

Magnetometer survey data from Knole Park, draped over the topographic surface derived from the GPS survey. The aesthetically pleasing image and the overview of the data all belie the need for a deep and reasoned analysis of what is essentially a high resolution dataset.

The analysis of geophysical survey data in archaeology is, to a large degree, based upon form or the morphology of anomalies within a dataset, together with the relative strengths or polarities of readings in the data. Archaeological evidence from excavation and coring can provide the surveyor with data that facilitates the correlation of hard data on the sediments and archaeological materials of an area with the non-intrusive data from survey, although such information is not always forthcoming. The morphology of anomalies becomes critical in the interpretation of spatially large-scale datasets where other archaeological data may be limited. This has been the case with two projects; the THaWS survey at Thebes, and the survey of the hinterland of Portus. In both instance the archaeolgoists have had to rely on the geophysical survey data, with limited excavation or borehole data present for the different areas. At Thebes, despite the massive quantity of archaeological remains on the West Bank and at Karnak, much of the survey work has focused on the Nile floodplain to the east of the extant archaeological remains. The nature of the deposits and constraints placed on the surveyors has meant that GPR and ERT have formed the principal methods of survey, with deep GPR profiles reaching 6-7m below the modern ground surface to locate potential archaeological features, complemented by ERT profiles reaching up to 19m in depth to assessthe geoarchaeological variations of the areas. While alignment of features with extant remains to the west has been possible. Some of the data interpretation is limited by the nature and quantity of associated archaeological evidence. Our interpretations and narrative therefore take on a cautious quality at times, as we cannot infer the presence of features without concrete evidence in the data, backed up by borehole survey and relating this to existing archaeological records. Our developing narrative for the landscape is thus providing new evidence for human interaction on the Nile floodplain, but is also changing the nuances of our methodological approach and epistomology. A similar approach is occuring on the Isola Sacra in the hinterland of Portus. Here there are fewer constraints on our ability to be able to survey in the landscape, although some varying land ownership and landuse has precluded survey in certain parts of the Tiber delta. However, our narrative to date has very much been based on the morphology of different anomalies, coloured by our existing knowledge of the landscape between Portus and Ostia Antica.

An example of the magnetometer data from the Isola Sacra. In spite of the high resolution expansive survey, our interpretations are limited by our existing knowledge of the landscape, leading to some general trains of narrative thought, but producing a number of unique surprises in the data, and opportunities for further investigation and clarification based on a continuous re-assessment of the methodology.

An example of the magnetometer data from the Isola Sacra. In spite of the high resolution expansive survey, our interpretations are limited by our existing knowledge of the landscape, leading to some general trains of narrative thought, but producing a number of unique surprises in the data, and opportunities for further investigation and clarification based on a continuous re-assessment of the methodology.

The massive scale of magnetometry in this landscape contrasts somewhat with the drtailed GPR and ERT surveys from within the archaeological park at Portus, with high resolution survey over smaller areas undertaken in close proximity to a number of seasons of excavation carried out by the Portus Project. Here the processing of and georeferencing of the data have occurred over the last few years, undertaken by a team of people, and the analysis and interpretation of the data have just been completed. What was immediately apparent from the data analysis was how a rigid system or process for analysing the data had to be established to deal with the complexity and three-dimensional nature of the datasets. The rationale ultimately was to pull order out of chaos, to take the complex representation of three-dimensional data and produce a sound interpretation and narrative for the data that could be understood in archaeological terms. The assessment of individual horizontal sections of the data, the creation of interpretative layers and the composite overlatying and assessment of these interpretations were key to this. The scrutiny that the data came under also allowed for detailed labelled plans to be produced, related to descriptive text using the labelling as a point of cross-reference. The interpretative layers could then be overlaid on the data from other datasets including the ERT, and plans of the site excavations.

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Example of the interpretative layers for the geophysics at Portus. The interpretation alows for detailed description of features, feature measurement and relation of features to the surrounding excavation plans. At this level of interpretation are we becoming too abstract?

The level of analysis for these datasets provides a good opportunity for giving detailed descriptions of anomalies and interpretations of features. However, beyond the reach of the excavation areas, we are still dealing with the morphology and signal of anomalies, and to a greater or lesser degree an empirical interpretation of these anomalies. Many of the insights into the geophysics here will be provided by archaeological knowledge of architectural styles and methods, and relating these to the plan from the geophysics. However the survey results are already leading to the development of an informed archaeological narrative for the survey areas.

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Portus Field School Week Two: canals, boats and local residents

The second week of the field school started in reflective mood, with a wander down the length of the Roman canal or Fossa Traiana that still forms the principal link between the modern town of Fiumicino, the coast and the Tiber. In spite of the balmy weather and the tranquil evening, the sea was in restless mood, with the waves breakingon the breakwater, and waves channelling up the canal, one after the other, pitching the fishing boats against the edge of the jetty. The fish market was a hive of activity, and all of the boats seemed to be in port, with the nets piled on the wharf. Some interesting parallels perhaps with the port architecture that we are excavating at Portus, now some 2km inland, with its own canals and waterways now infilled by river sediment and man-made infilling.

The jetty and canal in Fiumicino

The jetty and canal in Fiumicino

Work on site has carried on apace, with further emphasis beyond the excavation on laser scanning with James Miles, and geophysical survey in the form of ERT with Lizzie Richley. James has been surveying the the baths of the Lanterna, and the warehouse structures along the western side of the harbour of Trajan. Lizzie has focused the ERT in the area of Building 5 to the north of the Navalia excavation. Students have been rotated in groups to experience these non-intrusive methods, giving them a grasp of the advantages and applications of the different techniques, and the integration of this work with the excavation.

James demonstrating the Faro laser scanner

James demonstrating the Faro laser scanner

Lizzie and the ERT team

Lizzie and the ERT team

In Area K a number of the rooms (12, 7) are being excavated, through layers of dumped material and occupation layers. the team in Room 12 removed a substantial block of fallen masonry, and dug down through a dump layer containing brick and tesserae, hoping to eventually expose the opus sectile floor of the room. Camilla, having planned the offending masonry block, took the first ceremonial pick blow to it.

Excavation of Room 12 with Luke and the team

Excavation of Room 12 with Luke and the team

Camilla attacking the block

Camilla attacking the block

The students have been trained in the general methods of excavation, survey and recording on site, and as the work has progressed they have been involved in drawing plans, sections and taking levels amongst other activities.

Measuring levels for a flying section on site

Measuring levels for a flying section on site

Luke and Michaela on the dumpy level

Luke and Michaela on the dumpy level

In general, the deposits on the upper part of Area K are coming down on to the floors of rooms with mosaic and opus sectile , with remnants of opus reticulatum and brick walling. The hard work will come in the next few days in resolving the northern edge of these rooms, and the possible location of walls to these rooms, overlying the earlier mole wto which the lower floor of the palace abuts.

In spite of all of the hard work, and the focus on the archaeology, it is sometimes difficult to forget the natural habitat of the surrounding parkland. In addition to the green parrots, heron, and snakes, a number of residents have found a great dwelling place along the course of the bonifica canal running from the Trajanic Basin westward towards the edge of the site. A family of coypu live close to a bridge over the canal, at least two adults and two children, seen eating vegetation on the edge of tyhe canal each morning.

Coypu at breakfast

Coypu at breakfast

A further resident has also set up his abode in the Casale on site, making his way out of the upper floor of the building only to nibble at biscuits and drink strong coffee…

The new Casale resident

The new Casale resident

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Excavation and Survey at Portus: the first week of the 2013 field school

It isn’t difficult to understand the draw of working in fascinating or beautiful places on archaeological sites which represent pivotal moments in European history, and the case of Portus is no exception. This is a site and landscape close to my heart and research interests, more in terms of the development of the broader Tiber delta, than the Roman port per se. However, the nature of the port, its relationship with the city of Rome and the town of Ostia Antica and the changing fortunes of the site are compelling. Between 21st June and 14th July a field school, run by the University of Southampton, and directed by Prof. Simon Keay and Dr Dragana Mladenovic, is continuing the excavation and survey of a section of the port complex which commenced in 2007. The focus this time is the integration of different methods of a nalysis, both non-intrusive and excavation-based, to train students from a number of different institutions in the UK, Italy and elsewhere. As part of the season I am involved in the capacity of a supervisor and safety officer, so am really getting an idea of a small, limited part of the overall project and operation of the site in some aspects. In spite of this it seemed a good opportunity to blog over the next few weeks looking at the work and some of the broader thoughts arising from the work on site.

Setting up the barrow ramp to the north of the Imperial Palace Building 8

Setting up the barrow ramp to the north of the Imperial Palace Building 8

Looking north across the excavation

Looking north across the excavation

The team consists of different archaeologists and other specialists from the University of Southampton and further afield. In addition to the excavation supervisors from Southampton, Parsifal and the British School at Rome, James Miles and Peter Wheeler are working on digital scanning of parts of the site, and Lizzie Richley is carrying out high resolution Electrical Resistivity Tomography (ERT) across the area of Building 5.

Photography of the site from a cherry picker prior to commecment of the excavation

Photography of the site from a cherry picker prior to commecment of the excavation

The first week of work has focused on cleaning of areas of the site, photography from a cherry picker and gigapan photography, and the start of excavation in Areas K and N, including training of students.

Peter Wheeler photographing the site

Peter Wheeler photographing the site

Camilla Panzieri putting the finishing touches to a plan

Camilla Panzieri putting the finishing touches to a plan

Training on site has taken the form of thirty minute lectures on different aspects of the work on and off site, and longer lunchtime lectures, so far conducts by Simon Keay. The students then work on site, reinforcing the issues and theoretical ideas established during the lectures. Much of the work so far has involved explanation of the different methods of excavation and recording, and use o everyday equipment such as dumpy levels. All of the students seem to be engaged with the work and the broader project. There is still a lot to cover in the next two weeks, however, as the season moves forwards and excavation of the different areas continues into the rubble and occupation layers of the Imperial Palace.

Some of the walls and fallen masonry in the north part of the Imperial Palace. Topsoil still to be removed!

Some of the walls and fallen masonry in the north part of the Imperial Palace. Topsoil still to be removed!

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