Our Tyneside area has a 8ft thick seam of 'blue clay' a foot or two under the surface hence why we had brickyards dotted all over the area.There was another type called Fire Clay 5ft thick but that was about 40ft below the surface.Cambrian Blue Clay is the rarest and most ancient of all clays with deposits beginning in the earliest Paleozoic period of our history, about 542 million years ago. (I googled all this)
Here is a water filled quarry close to Mill Lane & St Josephs school 1960.The white 'Mill Tavern' can be seen on Mill Lane.