C—3a

28

Subject 7. — Geology, Surveying, and Making Plans. 1. Give a brief description of any coalfield with which you are familiar, giving especial attention to the following points : — (a.) Extent of the seam. (b.) Inclination of the seam. (c.) Faults, if any. (d.) Nature of rocks overlying and underlying. (e.) Character of the coal. 2. Define the following terms : — Auticline, overthrust fault, overlap, stratification, cleavage, jointing. 3. From the plan and particulars given below compute how many feet the working-face at G has encroached upon the adjoining claim, and what distance along the northern boundary from the corner of the claim marked A the working crosses the boundary.

Surface Traverse — Bearing. Distance. AB ... 182° 37' 1017 links. BC ... ... ... 96° 48' 503 „ CD ... ... ... 77° 32' 175 „ Underground Workings — * DE ... ... ... 89° 56' 174 feet. EF 7° 26' 384 „ FG 356° 28' 259 „ AH ... ... ... 96° 0' 4. The underground workings of a mine are enclosed within the figure below, the co-ordinates from A being as follows : — A ... ... ... ... o°'o' o°'o' B ... ... ... ... 768° 4' 74° 0' C ... ... ... ... 619° 7' 853° 9' D ... ... ... ... 31° 6' 532° 8' Required the area in acres contained within the figure.

5. Compute the cubic contents of an ore-dump 27 ft. 6 in. by 16 ft. 9 in. at base, 18 ft. 4 in. by 7 ft. 5 in. at top, and 4 ft. 9 in. high; and how would you ascertain the approximate tonnage ?