From Blacka Moor to Shorts Lane

 

A deposit of head with boulders in Blacka Plantation

At the end of my brief walk across the heathland at Blacka Moor Nature Reserve, which is underlain by the Chatsworth Grit, amidst the bracken I finally located the bridleway that heads eastward from the Piper Lane Car Park through Blacka Plantation.

 

An Ordnance Survey map of Blacka Plantation

 

Following the dip slope of the Chatsworth Grit at an angle of approximately 5 degrees, the bridleway has been deeply eroded to expose a deposit of head, described on the British Geological Survey map as boulders of sandstone in a clayey sand matrix, which I found quite difficult to negotiate in several places. 

 

A view of the bridleway to Blacka Plantation

 

I was too occupied trying to keep on my feet and I didn’t stop to examine any of the boulders and I presume that they and associated orange sandy deposits are from the Chatsworth Grit and have moved downslope by the process of solifluction during the Quaternary Period. 

 

Another view of the bridleway to Blacka Plantation

The scouring of the bridleway, which I would think can be quite hazardous for horses, has in places been repaired by the Sheffield and Rotherham Willdlife Trust with aggregate and roughly shaped slabs of gritstone and sandstone that have probably been sourced from the surrounding landscape.

 

Repais to the bridleway in Blacka Plantation

 

At some point on the walk, I passed from the head covered Chatsworth Grit and Rossendale Formation to the Rough Rock, which tends to be quite flaggy in the Sheffield area, but without a compass or a GPS device to pinpoint the location of the features that I encountered, I have not been able to determine the boundaries of these formations.

 

The bridleway in Blacka Plantation

 

I eventually arrived at the junction of three principal public footpaths through the woodland, at a point where various streams converge with Blacka Dyke, but I didn’t see any sign of rock exposures in any of the stream banks or streambeds. 

 

A signpost in Blacka Plantation

Carrying on the path until I reached the track that leads to Shorts Lane, I encountered a dry stone boundary wall that I presume is built using stone from the small quarry on the Crawshaw Sandstone that is marked at the end of Shorts Lane on the 1883 Ordnance Survey map. 

 

A dry stone wall and a sample of stone from it

 

I found a dislodged piece of quite thinly bedded stone and, after breaking it in half with my Estwing hammer, examined the fresh surface with my hand lens. The sandstone is buff/light brown in colour, fine grained and has degraded iron bearing minerals disseminated throughout and a scattering of white muscovite mica. 

 

The stepping stones on Blacka Dyke

 

Continuing east along the track next to the river, I next encountered a set of stepping stones over Blacka Dyke, which are very well squared and shaped and have a rounded top top surface that look like they may have been used as coping stones. 

 

The old quarry on Shorts Lane

 

Reaching Shorts Lane, a gap in the boundary wall aroused my curiosity and, although there are no rock exposures and only small terraces made of thinly bedded sandstone, this seems to correspond with the position of the old quarry mentioned above. 

 

A specimen of sandstone from the old quarry on Shorts Lane

 

The specimen of sandstone that I collected from the ground is buff/light brown in colour, thinly bedded with abundant white mica on the bedding planes and bands of orange coloured iron staining that is oblique to the bedding and are probably Liesegang rings. 

 

Dry stone walling on Shorts Lane

 

Shorts Lane takes a sharp right angle turn to the north, with a complex of modern stone buildings in the style of a range of old buildings on the corner. At its entrance is a fine example of dry stone walling, which is built out of a flaggy sandstone that reminds me of Greenmoor Rock, but this formation has not been quarried in Sheffield for a long time and it has very probably been brought in from West Yorkshire.

 

A detail of the dry stone walling on Shorts Lane