Geophysics in the Park: A Volunteer’s View

Last week the first physical part of the Big Dig got underway with the geophysical survey, led by the Museum of Liverpool.

We’re still awaiting the final report on the results before we post them up here, but below is a chance to hear a review of the day by one of our volunteers, Arthur, in his own words:

At last, Thursday; and geophysics in the Park.  There were seven of us assembled for instruction at the Mansion House and Liz introduced us to Mark Adams, our archaeologist and geophysicist for the day.  We had been given instructions: no metal at all, no zips, no pop closures, no eyelets, no rings or jewellery.  It was a cold wind out there and I ended up with long johns over pyjama bottoms, two sweaters and wellies.  Mark told us a bit about the magnetometer that measures very tiny variations in the magnetic field on the ground where it was pointed.  He measured us in anoraks with poppers – three times the magnetic ground level, off with the anorak.

Then off to the lawn in front of the Mansion House, a possible place for a new home for the Calder Stones.  With measuring tapes, lots of cane sticks and rope, Mark set up a 20m square marking a 3m, 4m, 5m triangle to get a right angle laid out. I didn’t know that Pythagoras was a geophysicist!  We then marked out lots of lanes on the square, setting sticks and using a rope marked in metres that we had to follow.

The magnetometer was like a huge TV aerial; a horizontal pole with a LED screen and buttons to press was hung from straps over your shoulder. The pole on either side had big vertical tubes which were pointed at the ground.  I wondered if you pressed the wrong button that red smoke might blast out of the tubes and send you flying through the air, but no, it was quite easy.  You walked along the measured rope and pressed a button at half metre intervals and the machine went ‘pip’.  It did a double ‘pip’ when you reached 20m then you did a U turn, moved the rope to the next stick and came back doing the same ‘step, button’ sequence.  Quite easy once you got into it.  There were forty lanes to measure and we all had a go, successfully.  Richard had to concentrate as his glasses had metal hinges and without these he was as blind as a bat and couldn’t see where he was going.  The rest of us were on dog-watch duty, chasing off dogs with metal studs in their collars that might interfere with the magnetometer.

We were really measuring low and high spots of magnetism.  Where a ditch had been filled with soil would be low magnetism and where there were stones or, particularly stones that had been heated in a hearth, would lead to higher magnetism.  The results came through the next day after Mark had crunched the numbers.  There was a series of low level ‘holes’ in a curve, but it was probably nothing more than a fence at one time.

I had to leave at lunch but the team repeated the process on a site behind the Mansion House and Liz and Mark showed them some theodolite work measuring horizontal and vertical angles to get an accurate map measurement relative to the house for the sites we had studied.

A really interesting day.  Archaeology and curiosity. You can’t beat it.

Thanks Arthur for such a great account of the day.

Let’s get (Geo)physical!

If you were in Calderstones Park yesterday you may have seen something quite different happening by the Mansion House.

A hardy gang of Reader volunteers braved the changeable March weather and the inquisitiveness of local dogs to carry out our geophysical survey – the first physical part of our Big Dig!

Eight volunteers of all ages turned up to our geophysics sessions which were led by Dr Mark Adams from the Museum of Liverpool who gave us a crash course in how geophysics works before leading us to the great outdoors for a hands-on magnetometer session.

Laying out the grid using the tried and tested ‘bamboo cane’ method.

Geophysics is the technology to look under the ground without having to dig. It involves using specialised equipment to send signals into the ground and then record what they detect. It takes a long time as each area has to be taken in small ½ – 1 metre steps before a computer crunches all the data to produce an image.

The volunteers helped to plan and lay out a grid, mark the area to be surveyed and then took turns in traversing the ground taking readings. Mark then explained how to use the theodolite to gain a reference for laying the grid over a map.

Just off camera is a volunteer desperately chasing dogs with metal collars away from the sensitive equipment!

Dr Mark Adams shows the volunteers how theodolites work.

And the results are…

…well you’ll have to wait a teeny bit for that!

Walking through Time with Ken Sloan

We were pleased this Saturday to welcome back a long standing supporter of our work at Calderstones – Ken Sloan.

Ken is a local environmental historian who has led numerous popular ‘time walks’ around the park.  His expertise in prehistoric Liverpool is formidable and he can lead you though the landscape of Calderstones as it was 4,000 years ago.

Ken is a keen enthusiast of the past and brought along some excting examples of prehistoric artifacts including a neolithic stone axe, barbed flint arrow heads and a replica clay urn – designed to look like the ones that were found in Wavertree over 100 years ago.

It’s likely that similar urns were buried in the Calder Stones for the cremated remains of Bronze age people living in this area 3000 years ago.

If you want to see the original urns they are on display at The Museum of Liverpool: http://www.liverpoolmuseums.org.uk/mol/visit/galleries/history/burial-urn.aspx. Free to visit!

After a brief talk about the stone-age, Ken took our intrepid visitors on a somewhat muddy but enjoyable romp through the fields of the park eventually finishing by the Calder Stones themselves.

The Big Dig: Dates Announced!

2015 is here, meaning we are getting ever closer to The Big Dig getting underway in Calderstones Park. A buzz of excitement built before Christmas thanks to the ever popular and mysterious Calder Stones, with many local enthusiasts enjoying a special tour and talk of the Stones by lamp light in the park with special guest, archaeologist and prehistory expert Dr George Nash.

With enthusiasm for discovery well and truly sparked, we can now announce when The Big Dig itself will be taking place. Get the dates in your diary!

The Big Dig will be happening from Monday 27^th April to Friday 8^th May 2015. Anyone and everyone is welcome to take part in the project – the very first time that Calderstones will be open and accessible to the public for historical excavation. The park has never been built on, meaning that we could find anything under our feet, perhaps even evidence of the first humans who lived in the area – relics from the earliest Scousers!

Before the two weeks of digging begin there’s plenty of preparation coming up to get involved in and clued up on the excavation processes. On 19^th January we held our Monday Mapping session at the Mansion House, with archaeologists from the Museum of Liverpool on hand to share their expertise and telling us about the Museum’s Interactive Map of Merseyside. It was a great turn out and wonderful to see so many people interested in getting mapping.

No need to fret if you missed out as there’ll be lots of other great events coming in the run-up to the Big Dig, with the first happening very soon around the corner.

The Museum of Liverpool will be holding four free tours of their prehistoric collection on Thursday 29^th January, including the chance to get up close and hands-on with some replicas of the Calder Stones themselves. Tours will be held at 11am, 12pm, 2pm and 3pm.

If you’ve always been intrigued by archaeology, come and get an insight into a day in the life of an Archaeologist at Ready to get Digging on Thursday 19^th February at Calderstones Mansion House from 2-4pm. Learn all about the tricks of the trade, including how to prepare for an excavation and how to choose where to dig.

Also at the Mansion House, join Ron Cowell – Curator of Prehistory at Museum of Liverpool – to delve deeper into the lives of the earliest people in Liverpool. Ron will be giving a talk about the Calder Stones and Merseyside during the Stone Age on Thursday 5^th March at 7pm.

Lots to get involved with! All the events are free entry, and you can register online at http://www.thereader.org.uk/events and http://www.liverpoolmuseums.org.uk/mol/events