Northumberlands Mississippi Blog
Mon 1st July 2013
28th June 2013
Flaming June it certainly was not; cool, wet and windy conditions prevailed with the cloudbase almost exactly on the top of Simonside. Nevertheless we started off at Tosson Lime Kiln with a quick introduction to the Carboniferous Period of geological time, an even quicker look at the geological map of the area and a closer examination of the kiln itself which brought all of the elements of that particular period of the earth’s history together i.e. the ancient geography and climate and the geology comprising of local Fell Sandstone, coal and limestone. Darren was happy when I got my tape measure out to show just how relatively recent the Carboniferous period actually was in relation to the total age of the Earth. Best of all we were able to do all of this sheltered under the draw arches of the kiln itself but we eventually had to go and get wet noting the now disused quarry close by. Up past the distinctive Iron Age hillfort of Burgh Hill and over the appropriately named Windy Crag we entered the Simonside Forest (i.e. large Forestry Commission conifer plantation) to shelter for elevenses half an hour late but welcome all the same. I found everyone a nice spot to sit and was sent down the hill to eat my scone; I think that everyone wanted some peace and quiet!
Elevenses over it was onward and upward up the scarp face of the Fell Sandstone towards the edge of the trees via the packhorse trail grooves cut in the sandstone and the nearby possible Neolithic rock shelter as archaeologist have interpreted it, it must have been a draughty spot but it did get everyone looking at the current bedding structures in the rock face. Out onto the forestry road below the Simonside Crags we could just see parts of the Cheviots with their contrasting rounded topography consisting of the granite masses of Cheviot and Hedgehope surrounded by the lavas of the former Cheviot Volcano (there may have been more than one volcanic cone but all evidence has long been eroded away). By contrast the crags of Fell Sandstone were bold, sharp and distinctive with more or less concordant summits as far as we could see into the murky gloom. On the climb up to the crest of the escarpment we had plenty of opportunity to see the sandy hillwash resulting from recent weathering and erosion and see the acid loving, heather dominated, vegetation associated with sandstone bedrock. It was time to introduce everyone to topset, foreset and bottomset beds in the current bedding and to appreciate how these predominantly shallow water sediments were originally deposited in the massive delta that formed Northumberland’s Mississippi in water that was quite shallow. The fact that these shallow water deltaic sandstones eventually accumulated to a depth of 300 metres plus had us looking for other mechanisms to explain this, that and a sincere desire to stop for lunch very soon.
A quick lunch was taken in the shelter of Old Stell Crag; it was too cool and windy to sit for long just at the cloudbase with no view. We moved quickly over Dove Crag and onto The Beacon descending by the old 13th century deer park wall to have a quick look at the Beacon Solar Observatory (re)discovered in 1987 by David Thompson. We soon located the Central Holed Stone (CHS) a long horizontal hole through a substantial block of Fell Sandstone aligned north-west to south-east. David did confirm that the sun shone directly through the hole at sunset on the summer solstice of 1988. We of course took the opportunity to look at the grain size distribution and cement between the sediments and draw parallels with beach environments today – well, I did anyway. Down off the steeper slopes we crossed Lordenshaws car park to have a look at the cup and ring marks etched into the Fell Sandstone relatively recently, only about 4,000 years ago by early settlers in the area! Over the moor past the Iron Age hillfort, younger still as this covered the period from approximately 800 BC to the arrival of the Romans in 43 AD and down to Whittondean Farm and Whitton Hillhead, both built of Fell Sandstone. Then it was back to our cars via Tosson Tower, a pele tower and reminder of the days of the Border Reivers disputes along the Anglo-Scottish Border between the late 13th and early 17th centuries. The huge facing stones of the tower (pele) were also of Fell Sandstone.
Thanks to Val, Darren, Selina, Maggie and Alan for your company, witty banter and interest, I hope that you enjoyed the geology even if the summer weather didn’t come up to par and that you see the distinctive Simonside Ridge, and the rest of the Northumberland Sandstone Hills, through different eyes whenever you manage to get out onto them in the future. Geological history really is “deep time” compared to human history. Remember Darren and the tape measure back at the lime kiln?
Monday, 01 July 2013