348 



PARTICULAR DESCRIPTION. 



About 1,000 feet (305 m.) up Kelly creek from the 

 brick works is situated a bank of clay from which material 

 is obtained for manufacture into common brick. The 

 section in the bank shows a bed of sand separating two 

 beds of clay, over which is about 15 feet of river gravels. 

 The beds are all of glacial or post-glacial origin and not 

 firmly consolidated, so that they can be worked by a 

 steam shovel. 



Two miles (3 . 2 km.) beyond these clay deposits is the 

 Thornton mine, the first mine at which the Eocene shales 

 are worked. These beds outcrop on either side of the 

 creek and consist of shales overlaid by conglomerate and 

 underlaid by sandstone. The beds are of Eocene age and 

 dip about 6 degrees to the southwest. The shale is 

 separable into two beds which are described by Dr. H. 

 Ries (4, p. 390) as "a lower grey shale of smooth plastic 

 character, and an upper purplish one which is harder and 

 grittier. The former is buff-burning, and on the south side 

 of the track is at least 6 feet (1.8 m.) thick, while the 

 upper or grey burning shale is 4 (1.2 m.) to 6 (1.8 m.) 

 feet thick." A test of the lower shale by Dr. Ries showed 

 it to be of good plasticity, burning to a good buff pressed 

 brick. 



A mile beyond the Thornton mine and on the opposite 

 slope of the mountain is what is known as the fire clay 

 mine. This was formerly worked as a coal mine and 

 contains a seam of coal up to 3 feet (.9 m.) in thickness. 

 The section at this mine as measured by Dr. Ries is as 

 follows: 



Sandstone 



Upper fire clay 8 ft. — 2 . 4 m. 



Coal with flint clay partings 6 in. to 1 ft. — . 15 to. 3m. 



Lower fire clay 7 ft. — 2 . 1 m. 



Ferruginous clay 4 ft. — 1 .2 m. 



China clay 10 to 15 ft. — 3 to 4.5m. 



Only the portion between the coal seam and the china 

 clay is at present being mined, a selected sample of which 

 fused Cone 32. The china clay is a fine grained whitish 

 clay fusing at Cone 22. It is not being mined. 



