Geology 



Our site was 2 miles from the outcrop, and the fall 

 would therefore be 276*6 x 2 = roughly, 550 feet. 



At the outcrop the base of the Permian was 650 feet 

 above the sea, and at our site 650-550= TOO feet. 



We now had the level of our site 750 feet and the 

 level of the Permian base 100 feet, and it was therefore 

 obvious that its depth below our feet would be 650 feet. 

 The surfaces of beds of rock are by no means plane 

 surfaces, and the surfaces below unconformities are often 

 extremely irregular, and some allowance must be made 

 for this. 



Taking all things into consideration, however, we 

 expected to penetrate the Coal Measures at a depth of 

 between 650 and 700 feet. 



The rock at the surface was Keuper Sandstone, and 

 this would have to be passed through before the Permian 

 limestones were reached. 



As the completion of the bore-hole would take many 

 months, we should not be able to be present during the 

 operation. It was therefore necessary for the boring to 

 be done with a diamond drill such as would bring up 

 cores, and these could then be preserved, carefully 

 numbered, for our subsequent examination. 



In the meantime we continued our exploration of 

 the country in the neighbourhood of Lyell. 



Some 15 miles above the town the river receives 

 two large tributaries, one on either bank. The one to 

 the west, Shale Creek, was navigable for canoes for 

 about 50 miles, and offered an easy route into the 

 area north of Coal Hill, much of which had been very 

 imperfectly explored. After some little delay we 

 managed to get two large and two smaller canoes, and 



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