 |
| A view across the Roundhay Park Fault to the Rough Rock |
Arriving
in Leeds from the south, the gentle dip and scarp topography formed by the Coal Measures strata fades away into the Aire Valley, with much of the city being
quite low lying; however, the topography changes quite dramatically to the
north, with a thick slab of the Elland Flags rising above the city to form
higher ground around Oakwood and Roundhay.
 |
| Roundhay Park Gorge |
Wandering
around Roundhay Park to take in the landscape, the original water courses have obviously
been obscured by the artificial lakes; however, the topography records the
erosion of the Elland Flags – and the Rough Rock – along with their associated
softer siltstone and shale, to form various gentle escarpments and vales.
 |
| A view across the Roundhay Park Fault to the Elland Flags |
The meandering brook, now gently flowing
through Roundhay Park Gorge, doesn't have the erosional power to have created the steep sided valley that now exists and this provides evidence that
fast flowing glacial meltwater - in Quaternary times - once cut through the hard rock.
 |
| A Geological Map of the British Islands |
Looking
at a Geological Map of the British Islands that hangs on my office wall – the 1969 edition, at the scale of 25
miles to the inch – there is a very distinct break between the Coal Measures
and the Millstone Grit, which I have often wondered about.
 |
| Folded Carboniferous siltstone and shale |
In South Yorkshire,
and the parts of West Yorkshire that I had previously visited, the Coal
Measures strata generally dip in a north-easterly direction – at Roundhay Park,
the sharp change in the landscape to the north of Victoria Park can be
partially explained by the appearance of the Roundhay Park Fault.
 |
| The geology around Roundhay Park |
The
Castle at Roundhay Park provides yet another unexpected insight into the variety of
geology that can be found around this part of West Yorkshire - to the east, there
is a deposit of Quaternary glacial till, which is the source of cobbles of Carboniferous sandstone used in its construction.
 |
| The Castle at Roundhay Park |
