﻿156 SULPHUREOUS STREAMS. July, 



for boats are very scarce. Though we did not 

 discover limestone in situ here, the beach is formed 

 of fragments of that stone of very various size, 

 mixed with some bituminous shale, and a few 

 granite boulders. This point is about thirty- 

 five geographical miles from Fort Resolution. 

 In a bay a little to the westward several sul- 

 phureous streams issue from a limestone con- 

 taining corals. The channels of these streams are 

 encrusted with a similar tufa to that observed on 

 Clear- water and Athabasca Rivers, and the organic 

 remains that have been examined indicate the 

 formations to be of the same geological epoch.* 



July Idth. — Embarking at three, we passed the 

 mouth of Buffalo Lake River, and after five 



* The fragments of black and bituminous shale which strew 

 the beaches of these islands, and which evidently have not 

 travelled far, contain a " pteropodous shell ( Theca) apparently 

 the Tentaculites fissurella of Hall, a Chonctes, the Strophenenia 

 setigera of Hall, and Avicula Icevis of the same author ; at least 

 they are undistinguishable from his figures of these fossils in 

 the Marcellus shale, which according to him is upper silui'ian, 

 but is probably somewhat newer, and what Ave call Devonian. 

 Two corals in the associated bituminous limestone are cha- 

 racteristic of the same epoch, namely a Strombodes of Hall, 

 having its cysts filled with bitumen, and a Favosites very like 

 the common F. folymorpha of the Plymouth marbles. I have 

 not identified any of the TerebratulcB from Great Slave Lake, 

 but they are certainly either Devonian or carboniferous, and 

 not Silurian. There is notliing like a secondary fossil in the 

 collection."- — Woodward in lit. 



