English: Plate XXV from The Geology of the Richmond Basin published by USGS, which has the following caption:
Plan and sections of old workings on eastern border, Richmond Basin. (After Clifford.)
The text of the report refers to this figure as follows:

Jewett's coke shaft.—The section at Jewett's coke shaft, near Midlothian, not now accessible, was studied by Clifford, who gave the section represented in Pl. XXV, reproduced from his paper. He also gave a plan showing the relations of the Blackheath field to the main basin (Pl. XXV) and a section of the Blackheath district. Explorations made during the progress of the present survey showed that the thick coal seam of this tract is brought against the granite on the north end by a fault, and that there is a thin seam of coal below the main bed, separated from it by a few feet of shale, which rock again intervenes between this coal bed and the granite.

Later the report states:

Famous in the early mining history of the Richmond coal field is the small area on the eastern margin lying mainly on the north of the line of the Southern Railway (see Pl. XXV). This area appears from the statement of old miners and from such information as can be gleaned at the present time from the materials about old pits to have contained two rather distinct troughs of coal, an eastern one known as the Blackheath Basin, and another one, known as the Cunliffe, lying between this and the main basin.