Geophys at dawn

As dawn broke a  few weeks ago, four archaeologists approached Baker’s Flat, near Kapunda. Our mission – to carry out a geophysical survey of part of the site.


Dawn over Baker’s Flat, March 2016

The picture below shows the first line we recorded.  Kelsey’s starting the ground penetrating radar, and we’re all feeling bright and chirpy.


Using the GPR on the first gridline

Four days later, we’re not so bright and chirpy. It’s very very hot and dusty, the sun reflects off the wheat stubble making it even hotter, we’re each averaging more than 23,000 steps a day whilst pulling machinery or dragging ropes. Archaeology – it’s not a glamour sport.


Here I am, pulling the GPR, hot, determined, not glamorous. Photo: Kelsey Lowe

We covered an enormous amount of ground. We worked in 20 metre square grids, constantly moving ropelines which allowed us to walk the grid at even 1 metre intervals. By the last day, we had recorded most of a 240 metre x 100 metre grid. It doesn’t take long to write that but it took a week to do it!


Kelsey operating the magnetic gradiometer while Jordan and Lynley move ropelines

And here’s the glamour bit – downloading the data at night and finding great results. The picture below shows the initial results from the magnetic gradiometer. You can ignore the green squares – they’re the bits we didn’t do, such as the large pepper tree we just couldn’t get through, and the six grids at the bottom right that we didn’t survey. Instead, cast your eyes to those beautiful straight lines near the bottom of the picture, the ones that are triangular and rectangular in shape. Nature doesn’t create straight lines, so these are made by people. And I think that they may be field enclosures – one of the hallmarks of a clachan (traditional Irish settlement). Above the long green rectangle (in real life, a pepper tree) are clusters of white blobs, which I think  are structures, and I’m hoping that they’re houses. You saw the field in the photos above – there is no indication above ground that these structures lie below. The geophys results in this instance are critical in guiding the excavation strategy for the site.

Second Mag Results Entire Grid 03-03-16

Cool results from the magnetic gradiometer

And finally, huge thanks to the fabulous and gracious Kelsey Lowe, Lynley Wallis and Jordan Ralph for donating their time and considerable expertise to work in extreme conditions with me on Baker’s Flat, in the interests of archaeology and science. All they got in return were the last drops of a bottle of gin, blisters, and my gratitude.

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