Below is shown a section of the various strata at the Glyn Pits. The thickness of the coal measures was:
At 52 yards depth was the 'Soap Vein' at 2 feet six inches.
At 88 yards was the 'New Vein' or Elled coal, at 4 feet.
At 104 yards was the 'Droideg' coal, or 'Big Vein'.
At 117 yards was the 'Red Vein' or 'Three-Quarter coal' at three feet eight inches.
At 143 yards was he 'Rock Vein' or 'Black Vein' at eight feet.
At 149 yards was the 'Yard Vein' coal, at two feet six inches.
At 152 yards was the 'John Williams' coal at 12 inches.
At 171 yards was the 'Meadow Vein', at ten feet two inches.
At 178 yards was the 'Old Coal' at five feet six inches,
And at 190 yards was 'Rough Coal' at one foot ten inches.
As will be seen, there were various other strata including ironstone, which was also mined at the Glyn Pits.
