Two days in the Park…

… Page’s Park, Leighton Buzzard, this time! CAGG teamed up with members of the Leighton Buzzard and District Archaeological and Historical Society to undertake a survey in Page’s Park which is next to the light railway.  Why here?  There is an early reference to the find of a “Roman well” in the Park which is marked on the OS maps.  Here is the description from the Bedfordshire HER:

A supposed Roman well was found at Stonhill (Page’s Park) in the mid 19th century. The structure was lined with sandstone. Red deer antlers were found in the well, but no datable finds. Other depressions visible on air photos of Page’s Park are likely to be the results of quarrying.

We spent two days in the Park and managed to survey nine grid squares on the first day and twelve on the second.  Quite a feat to cover so much ground.  It was a challenge for me too as I was trying to lay out the 40m grid using  UCL’s nice new shiny dGPS but not aligned on the OS grid this time. The layout of the park made it more sensible to rotate the grid about 30 degrees anticlockwise.  I’m glad to say it worked, but I am painfully aware I need to learn how to use QGIS for the data processing.  It helped that there was a good ‘phone signal for a change, but the nice mature trees were a problem around the edges.  The Park also has a surprising amount of topography. The NE side where the cricket pitch lies is quite flat but the SW side is surprisingly hilly.  Even the football pitch lies in a hollow.

Pauline Hey heads for the goal.

Pauline Hey heads for the goal.

As one might expect, there was considerable modern interference: two goal mouths, a mast for a CCTV camera, manhole covers indicating the presence of utilities…

Page's Park magnetometry survey.

Page’s Park magnetometry survey.

A first glance at the results of the survey shows these features quite clearly. The vast majority of strong readings, shown as black or white in the plot, are modern features: the gas pipe which runs along the northern edge of the park, the utilities for the cricket pavilion, as well as some other unknown ferrous items.  I have plotted some of these in the next figure.

Some of the modern features in the Park.

Some of the modern features in the Park.

Two of the questions which arose from looking at the plot of the first day’s work (the area to the left of the line of trees) were: what are the two curving lines in the top-left corner and more centrally (both marked as ‘edge of slope’ above); and why does the depression near the approximate location of the well have such a strange mixed but strong signal?

To answer the first question I decided to use the new dGPS to undertake a rapid topographic survey of the area to the west of the trees (another first for me!).  The next three images show the results: firstly the topo survey, secondly the mag survey of that area and lastly the two overlain but with the topo survey made moderately transparent.

Topographic survey of the Park.  Green is low, white is high.

Topographic survey of the Park. Green is low, white is high.

The western half of the mag survey.

The western half of the mag survey.

The topographic survey overlain on the magnetic survey.

The topographic survey overlain on the magnetic survey.

As you can clearly see, some of the curving features are clearly the result of the topography.  Most probably they are the result of the magnetically enhanced topsoil accumulating at the bottom of the slopes.

What about the funny “depression”?  This could be clearly seen on the surface.  I have boosted the colour and contrast in the next image to make it clearer on the photograph.

The depression in the park.  The colours and contrast have been boosted.

The depression in the park. The colours and contrast have been boosted.

The depression can be clearly seen in the topo data, and on the ground.  It is near the approximate site of the well as far as we can tell from the 19th century records.  This could be the well, but why does the survey show such a busy strong pattern?  Towards the end of the first day some of the workmen stopped to chat.  One told us they had dumped two foot or so of material from the old car park in the hole!  This could still be the well, but the results from the mag are more modern noise.

Having discounted slopes, pipes, rubble and goal posts, did we find anything?  There are a number of features which merit more attention.  I have marked some of them in the next image.

Possible archaeological features in the survey data.

Possible archaeological features in the survey data.

These are only a few of the possible features.  There are also a number of potential pits.  Sorting this out in detail will require much more time to go through the data carefully.  Of course, we cannot date these features and further interpretation will require a careful look at any historical or map data that might be available, or even the excavation of some carefully targeted test trenches.  The value of a survey such as this is that any test trenches can be placed precisely in order to examine the potential archaeology, rather than being placed randomly with the hope of hitting something interesting!

Many thanks to all that helped including Pauline Hey, Bernard Jones, Richard Gleave; Trudi Ball, Miranda McGarry and Jeff Langdown.

 

A tale of two villas

CAGG teamed up with the Chess Valley Archaeological and Historical Society to undertake surveys near two Roman villas: Latimer and Sarratt.  Latimer (Bucks) has been known since the 19th century, was excavated by Keith Branigan in the 1960s and was published by him in 1971.  The Sarratt (Herts) villa site is less well known . However, in 1907 the remains of an apsidal building were uncovered by the local farmer.  Field walking the area in the 1960’s by CVAHS found large quantities of scattered building materials and pot.  The present day CVAHS team has worked on this site since 2006, and assembled evidence for a large Roman settlement present from the late Iron Age though to the 4th century (CVAHS Journals 2006-2012).

The survey at Latimer

The survey at Latimer

Two areas at Latimer were available for survey.  The first was a strip of pasture between two arable fields to the south of Latimer Road.  This strip has quite mature trees on it and had not been ploughed within memory. The second area was a small pasture to the north of the road leading towards the river, which at this point has been dammed to form the lake for Latimer House.  We managed to finish both these areas on Monday 14th July 2014.

As can be seen from the results, we didn’t find much.  The southern area has some linear stripes, which may be old plough features.  They line up nicely with the fence line to the south-west.  The northern area is very noisy indeed.  It rather reminds me of the excavated areas at Verulamium and my guess is that there is a certain amount of building debris left over from the demolition of a nearby building.  Of course, we must remember that negative evidence just means there were no magnetically enhanced features to find, it does not mean there is no archaeology present.

The survey at Sarratt.

The survey at Sarratt.

The following day we moved further down the valley to the site at Sarratt, just south of the river, and adjacent to fields where Roman features have been uncovered.

Downloading the data at lunchtime. Photo: Phil Nixon CVAHS.

Downloading the data at lunchtime. Photo: Phil Nixon CVAHS.

Unfortunately, we failed to locate any archaeological structures here either which was a great shame.  We did, however, have the fun of watching CVAHS member Phil Nixon flying his quadcopter over the site to take photos and video of the work in progress and the site in general.

Many thanks to everyone who helped on the survey and especially to Yvonne Edwards and David Hopkinson for putting us up for the night and Jim West for returning the equipment.

The next survey will be in Leighton Buzzard!

Two sunny days at Ashwell

We had a short window of opportunity between cuts of silage to return to the site at Ashwell and extend the survey we started last year.  Although the Iron Age site had been surveyed previously by Mark Noel, the Foerster allows us to take many more readings per square meter which gives a clearer picture.  Many thanks for Sam Sheppard for allowing us access to the field.

The Institute of Archaeology, UCL, now has a dGPS to which we have access.  The site grid should have been easy to lay out as a result.  Unfortunately, the phone signal was a little weak so it took longer than I had hoped, but it did the job eventually, and the data matched the previous survey perfectly which was a big relief.  We managed six grids on Monday and an excellent ten grids on Tuesday.

Combined plot of the survey's at Ashwell.

Combined plot of the survey’s at Ashwell.

The first image shown above shows the Roman cross-roads site we surveyed previously on the top-left.  The main survey area is a composite of the previous three days of survey plus the two new days.  Luckily, no sign of a join!

The Iron Age site.

The Iron Age site.

This second image focuses in a little more on the Iron Age site.  As you can see, there is a whole mass of ditches and pits in this area, some very strong and some more subtle.  Disentangling and phasing these results is going to be quite difficult, if not impossible without some excavation to test the relationships.  It does, however, clearly show a multiphase settlement with trackways and enclosures.

Many thanks to all who turned out to help on two beautifully sunny days and contributing towards this excellent result.

 

Datchworth Church

Something a little different this time. The CAGG team were asked a favour by the Parochial Church Council at Datchworth.  Basically, they are running out of space in the graveyard.  A local farmer has offered them some land to extend the cemetery, but because of the possibility of archaeological remains in the area they need to have an assessment done before they can extend the churchyard.  Some ten years or so ago, the Welwyn Archaeological Society did some limited excavations in the area prior to the building of their church hall, and so we were approached to see if we could do a geophysical survey.  The area which will be affected is quite small, so we did the mag survey of the entire field over a day and a half, during which time we managed a resistance survey at 0.5m spacing of the key area.

The resistance survey at Datchworth underway, 19/4/2014.

The resistance survey at Datchworth underway, 19/4/2014.

We undertook the survey over two days, the 13th and 19th April 2014.  The mag survey was finished by lunchtime of the second day and would have been even quicker if it wasn’t for the awkward shape of the field — resulting in every grid (bar one) being a partial.

Results of the magnetometry survey.

Results of the magnetometry survey.

The mag survey shows… not a great deal.  The important area to the north of the current churchyard shows nothing much at all.  To the east of the church there are some potential features, but the most likely area is the northern part of the survey.  This spot also has lots of lumps and bumps and the farmer thinks there may have been a building there.  The clarity of the survey is badly impacted by the large quantities of farm machinery parked there and a farm shed.

Results of the resistance survey.

Results of the resistance survey.

The resistance survey was much slower.  When taking readings every 0.5m, it takes a day to cover the area the mag completes in about 40 minutes!  The high resistance feature (shown in black) that runs along the western edge of the survey, is a bank running parallel to the ditch that runs along the road.  The other features are not visible on the surface.  High resistance features are usually things like roads, paths, walls and sold floors.  In this case, we appear to have a linear feature running N-S to the west of our survey area as well as a second one near the “moat” at the top.  I need to ask around a bit more before committing myself to a particular interpretation, but they are certainly too wide for a wall.

 

 

Little Hadham

Today we ventured out to the east of the county to survey near Little Hadham. We had done a little survey at the site last autumn but returned to examine a more fruitful looking field today.  Many thanks to all who turned out, we had quite a large team.  As we wanted to finish the area we knew contained features we worked on until 6pm.  I think the results were worth the effort.

Results of the survey on 6th April 2014.

Results of the survey on 6th April 2014.

The surface finds included late Iron Age and Roman pottery and it looks like we have a small enclosed farmstead with an associated field system.  Clearly the features go further to the south and east, and metal detector finds show that it continues to the west on the other side of the road.  Previous survey suggests there is not much more, if anything, to the north.

The ridges from the cultivation show in the plot as the lines to running east-west, and there is a little stagger error, but nothing too bad.  We can’t always survey on nice smooth parkland!

Another success for the CAGG team!

News Update

End of term madness as well as conferences in Basel and Reading have stopped me from working on the project for a few weeks. Yesterday I spoke to the Roman Archaeology Conference in Reading and there is great interest in our results.

A couple of upcoming events.  On Thursday evening (3rd April 2014) I will be delivering a lecture about the project as part of Verulamium Museum‘s Thursday evening lecture series.  It starts at 7.30pm at the Museum, all welcome.  Then on Saturday 5th April I will be giving the Gordon Moodey Lecture after the AGM of the East Herts Archaeological Society which is to be held in Great Amwell Parish Hall, 2.30pm.

We plan to start surveying again very soon and we will be emailing the trimmed down mailing list about that soon.  Meanwhile, a few photographs to remind you all of the joys of working in Verulamium Park in the wettest winter on record.

Ralph Potter (WEAG) teaching UCL students how to use the GPR.

Ralph Potter (WEAG) teaching UCL students how to use the GPR. Note the mud on the wheels!

Jim West (CVAS) negotiating the trees and undergrowth near the southern edge of the site.

Jim West (CVAS) negotiating the trees and undergrowth near the southern edge of the site.

Rainbow over the Park.

Rainbow over the Park.

Ralph’s great data

Last Monday and Tuesday we were out in the Park, partly continuing our survey but mainly to teach masters level students from UCL.  Many thanks to Jim West, Pauline Hey, Mike Smith, Peter Lilley and Ralph Potter for acting as unpaid teaching assistants!

Although we did some magnetometry (with both the Foerster and the Bartington) and some resistance, the star of the show is Ralph’s Ground Penetrating Radar (GPR) data.  Ralph provided me with a movie showing his results and the raw data.  I’ve long wanted to learn how to slice GPR data so with Larry Conyers’ program, and Larry’s patient help, I sliced the data myself.  Many thanks to Larry and Ralph for their help and the data.  The first image below shows the location of the GPR survey: a 50m by 40m grid partly over the 1955 ditch but also over some known buildings.

Location of GPR survey undertaken in February 2014.

Location of GPR survey undertaken in February 2014.

The next and long sequence of images show the mag data on its own, and then each of six time slices.  These represent increasing depth although at present all I know is time going from 8 to 32 nanoseconds (ns) in 4 ns slices.

Foerster magnetometer results in the area where the GPR survey was undertaken, February 2014.

Foerster magnetometer results in the area where the GPR survey was undertaken, February 2014.

Time slice for 8-12ns.

Time slice for 8-12ns.

Time slice for 12-16ns.

Time slice for 12-16ns.

Time slice for 16-20ns.

Time slice for 16-20ns.

Time slide for 20-24ns.

Time slice for 20-24ns.

Time slice for 24-28ns.

Time slice for 24-28ns.

Time slice for 28-32ns.

Time slice for 28-32ns.

As can be seen we have some beautifully clear buildings including one which overlies the 1955 ditch.  We also seem to have a road inside the 1955 ditch which I haven’t seen postulated on maps of Verulamium.   One of the many questions which comes to mind is whether the big rectangular area to the west of the plots is only the result of the cricket wickets or is there an underlying building as well?

Just to finish I include one last graph showing the single 20x20m resistance data plot on the GPR data.  There is excellent agreement.  Given how utterly saturated the ground is I am surprised anything shows, but the results are OK, if not stunning.  The dark band is probably the road which runs to the south of the 1955 ditch which has been seen before.

Resistance data overlain on the GPR and magnetometry data.

Resistance data overlain on the GPR and magnetometry data.

Next week we’ll be out again working under the trees to finish off the last few bits.