CHAPTER XIII 

 THE LAKE FAULT OIL GOLD 



THE foliage of the trees which fringed the river and 

 occupied the lower slopes of the neighbouring hills 

 rendered it somewhat difficult to see the structure of 

 the country, but by landing from time to time we were 

 able to ascertain that we were still in the limestone 

 area. There followed a tract of woodland country many 

 miles in width in which there were no exposures of the 

 solid rock anywhere in the neighbourhood of the stream, 

 and the river meandered considerably. Then the 

 valley once more narrowed and we entered a gorge, 

 the sides of which consisted of dull-grey grits and shales 

 with a few layers of black Carbonaceous shales in which 

 we found numerous graptolites belonging to the genera 

 Monograptus, Cyrtograptus, and Rastrites, from which 

 we knew the rocks to be of Silurian age. It was 

 probable, therefore, that we had crossed the line of 

 the Lake Fault, the second of the great dislocations 

 affecting the plateau area. 



Being anxious to locate the fault line as closely as 

 possible, we landed to explore the surrounding country, 

 and seeing that a tributary stream was so useful to us 

 in the case of the Camp Fault, we followed the banks 

 of a small river which came in from the east. For 



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