Page 299 - Introduction to Mineral Exploration

282 M.K.G. WHATELEY & W.L. BARRETT

N
Bardon Hill Charnwood
13
Forest

Fig 12.2

Billa Barra Hill
Stud Farm
Cliffe Hill
Quarry
11
Bradgate Park
Stanton under
Bardon

9 Railway

0 1 km M1 A50
line to Leicester
45 47 49 51 53

FIG. 12.1 Distribution of markfieldite (a microdiorite) in the southern part of Charnwood Forest,
Leicestershire, UK. Stippled areas are known and projected areas of markfieldite as given in Evans (1968).
Hatched areas are other intrusive rocks. The grid coordinates are in kilometers.

Knowing the location of faults is important in This case study gives a clear example of
any quarry. Associated minor faulting is also the procedure adopted by one company in the
important to quarrying operations. In Cliffe exploration for and development of a hard
Hill Quarry one apparently minor shear zone rock resource. Readers wishing to expand their
was mapped. As a minor feature it could easily reading into sand and gravel and limestone
have been missed during core logging, however resources are referred to British Geological
it offset the Precambrian basement by almost Survey publications on the procedures for the
60 m (Bell & Hopkins 1988). assessment of conglomerate resources (Piper
In order to maintain its production from the & Rogers 1980) and limestone resources (Cox
English Midlands, and to maximize the exploi- et al. 1977). Additional background reading can
tation of a valuable national resource, Tarmac be found in the book by Smith and Collis (2001).
initiated a search for alternative sources of
similar quality markfieldite in the neighboring
areas. This search was conducted in a number 12.2 PHASE 1 – ORDER- OF- MAGNITUDE STUDY
of phases with each subsequent and more
costly exercise only being undertaken if clearly Cliffe Hill Quarry is adjacent to the M1 motor-
justified by the results of the preceding one. way and a railway giving it excellent access
All costs quoted in connection with this case to major markets in the southeast of England.
study relate to values current at the time of the The initial desk study in 1977 concentrated on
expenditure. extensions to Cliffe Hill Quarry and adjacent