The excavation of this pit was commenced in 1928, continued in 1930 and 1932 and completed in 1933. A brief account of the work up to the end of 1932 is included in the Interim Report of the Percy Sladen Trust Excavations 1927–1932 published in Proceedings, viii. 5. p. 60.

Pit 12 is situated at the extreme eastern end of the West Field the boundary fence of which intersected a segment of the shaft and was removed during the excavations. Consequently, the pit is only a few yards distant from the nearest pit of the visible series and within the zone which in my Presidential Address, in 1926, (Proceedings v, 13, p. 125) it is postulated that the type of mining represented by the deep visible pits commenced. In the same Address, (p.95), it was indicated on the evidence of the polished stone celts and the methods adopted in mining, that the visible pits were clearly of Neolithic date, therefore the fortunate discovery of typical Neolithic pottery in Pit 12, is not surprising, though of first class importance for dating purposes in the light of our fuller knowledge of Neolithic pottery. It also confirms and definitely establishes the conclusions arrived at in 1926 relative to the age of the deep pits and furnishes for the first time a datable horizon for the commencement of this mining phase.