Monday, 17 October 2016

"Hooton Roberts Rock"


A detail of the "Hooton Roberts Rock" in situ

When I first visited Rotherham 35 years ago - as an undergraduate geologist - I became aware of the very distinctive variety of Mexborough Rock that is known locally as “Rotherham Red” sandstone, which has been used extensively as a building stone in Rotherham and the villages in the south of the borough where it outcrops.

A view of the landscape around Hooton Roberts

Especially when there are no crops growing, the red staining of the soil is obvious and, having since surveyed much of the geology of Rotherham and its historic buildings, I have always thought that the village of Hooton Roberts was built on or very near to this rock.

Red sandstones in Hooton Roberts

Continuing with my investigation of the mediaeval churches of Rotherham, when I planned my first visit to St. John the Baptist's church – whose oldest externally visible fabric is built out of very strongly coloured red sandstone - I was surprised to discover that it is shown on the British Geological Survey map viewer as a Pennine Upper Coal Measures Formation sandstone.

Yellow sandstone in boundary walls at Hooton Roberts and Thrybergh

This generic name is used to describe a rock formation that does not possess physical or palaeontological characteristics – or is not sufficiently extensive or prominent as a landform – to make it so distinctive from another sandstone to give it its own name.

Cleaned samples of "Rotherham Red" sandstone and "Dalton Rock"

Without having the resources of the British Geological Survey at your fingertips, and access to the vast collection of rocks and other information that has been acquired over the years – or full authority to enter upon land without objection – it is not easy to contest the findings of an institution that leads the world.

An investigation of the "Hooton Roberts Rock"

My copy of the 1989 reprint of the 1947 edition BGS memoir, which accompanies the Institute of Geological Sciences map - Barnsley (Sheet 87) enlarged to 1:50,000 scale and reprinted in 1976 - describes the sandstone underlying Hooton Roberts as either Dalton/Brierley/Great Houghton/Cadeby or Hooton Roberts Rock.

Bullrushes and other water loving plants growing on a spring line

Getting off the X78 bus at the first stop after Hooton Roberts, on the way to Conisbrough and Doncaster, I walked down the hill to the village and stopped several times to take photographs of mapped areas of Mexborough Rock, a spring line and various boundary walls - from which I collected a few samples of loose stone.

Foundations of the churchyard wall at Hooton Roberts

Finally arriving at St. John the Baptist's church, I examined the bedrock that forms the foundations of one of its boundary walls and - having had a conversation with an owner of one of the surrounding houses where excavation in the basement revealed a very red sandstone - I decided that it was time to invest in a new compass/clinometer to make some dip and strike readings.

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