at 50m deep is it possible it reached a seam ? Could have been a nice explore !
Quite possibly as the site is close to the ridge between the Wear and the Gaunless. There are a number of seams here at shallow depth, and there's general acceptance of unrecorded old surface workings. Also there have been several open-cast sites within a mile or so to the south.
Whilst not the immediate property where the hole opened, this is from a planning application a few years back, a bit higher and to the west...
| ôŹ°¨ôŹ°©ôŹ°ˇSeam | Depth (m) | Sect | Date | ôŹ°ôŹ°©Remarks |
| Bottom Busty | 30 | | Pre 1947 | |
| Brockwell | 59 | | Pre 1947 | |
Another planning application gives:
"The Busty seam is shown to be located at 33 feet (approximately 10.05m) below ground level with a section thickness of 48 inches (approximately 1.21m), in two leaves. The Brockwell seam is also noted within this borehole at 120 feet (approximately 36.57m) below ground level, which is inferred to outcrop to the south-west of the site."
Both those sites are south west of the sink hole, and the geology indicates the seams dip to the north, so the coal seams have likely gone a bit deeper.
Incidentally, the sink hole isn't far from the Etherley Incline - the start of the original Stockton & Darlington Railway. (The first few miles to Shildon were rope hauled inclines, one being the Etherley Incline and the other being the Brusselton incline. Once at Shildon they could switch to loco haulage to head for Stockton. )
