Home » categories » rare book library » Lewiss. Genesis and Matrix of The Diamond.
This chapter is tagged (labeled) with: 

Final Notes

Final Notes Page of 85 Index Text size:minus plus Restore normal size   Mail page  Print this page
NOTE
69
layer by layer. While the last sheets of this book were in the press Sir J. B. Stone, M.P., F.G.S., sent me a collection of specimens which he had recently received from this mine, among which were pieces of the diamond-bearing rock, of which the deepest was labelled 1,400 feet, and I saw blocks from nearly as far down in a collection shown to me by Mr. W. Crookes, F.E.S. A particularly well-preserved specimen which he has lent to me for study came from 1,320 feet.
He has also favoured me with a copy of a section re­presenting the workings in this De Beers mine. The shaft has reached a depth of quite 1,500 feet, and from it the lowest level is being driven. The section of the ' country rock,' outside the ' pipe ' containing the diamond-bearing breccia, is as follows: (1) superficial debris, (2) basalt, (3) black shale, (4) ' melaphyre,' (5) quartzite, (6) ' slate'—pro­bably only a hard shale, (7) quartzite and ' slate.' Dykes (probably basaltic) pierce into (5), through (6) and (7). The ' melaphyre ' (4) is about four hundred feet thick. The area of the workings is twenty-two acres. It is the least of the four mines mentioned on page 1; Du Toits Pan, the largest, being forty-five acres. Since Professor Lewis wrote, another important mine (the Wesselton) has been opened; it is included within the same circle as the last-named.
T. G. B.
Final Notes Page of 85 Index
Table Of Contents bullet Annotate/ Highlight
Lewiss. Genesis and Matrix of The Diamond.
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page