104 A. J. R. Atkin — Gold on Lightning Creek, B.C. 



EXPLANATION OF PLATE IV. 

 Fig. 1. Sarpes sp. ' Horse-shoe ' limb. Sholeshook Limestone, x 3. 

 ,, 2. Anipyx cf. rostratus, Sars. Head - shield. Slade Beds, Upper Slade. 



x2|. 

 ,, 3. Remopleurides Salteri, Reed, var. girvmiensis. Slade Beds, Upper Slade. 



X 2i. 

 ,, 4. Aeidaspis Turnhulli, sp. nov. Nearly entire specimen, with the exception 

 of half the thorax and pygidium. Sholeshook Limestone, Haverford- 

 west. X 2. 



,, 5. Outline figure of restored head-shield. 



,, 6. Restored outline of one of the thoracic segments. 



,, 7. Restored outline figure of pygidium. 



,, 8. Aeidaspis sladensis, sp. nov. Head-shield, showing the glabella; the 

 cheeks imperfect. Slade Beds, x 5. 



,, 9. Head -shield of a larger individual, x 5. 



,, 10. Restored outline of head-shield. 



,, 11. Pygidium. x 5. 



,, 12. Outline of pygidium restored. 



,, 13. Lichas affinis, A.nge\m,y&v. Pygidium. Slade Beds, Haverfordwest, x 2. 



11. — Some Notes on the Gold Occurkences on Lightning 



Ckekk, B.C. 



By Austin J. R. Atkin, Esq. 



LIGHTNING CREEK occupies a wide valley in a weakened zone 

 in the series of rocks known as the Cariboo schists. It has 

 been stated by Mr. Bowman (Canadian Geological Survey, 1885 and 

 1886), and confirmed by later observations, that the centre of the 

 deepest known erosion follows very closely the anticlinal axis in these 

 schists. The occurrence of the very rich spots for which this stream 

 is justly famous, both below its present level and at points many 

 feet above it, have long been a source of discussion amongst the 

 miners who worked here. It is hoped these notes gathered during 

 three years studying this difficult problem may be of assistance to 

 future observers, and perhaps lead to the discovery of rich benches 

 in hitherto unsaspected places. 



There have been four distinct channels followed by this stream, 

 all of Tertiary age. The oldest or Devil's Lake stream (see map) 

 emptied into a different river from the present creek, and is about 

 600 feet ' above the channel of the latest Pliocene stream, at present 

 buried under from 50 to 150 feet of drift of Glacial and Pleistocene 

 age. Between this and the latest Pliocene cliannel are the Butcher 

 and Dunbar Flat Benches, both the sole known remains of a stream 

 which once ran at this level. 



Below these, and only about 20 feet above the deepest channel 

 yet discovered, is the bench belonging to the Point Mining Company, 

 which I have called Fry's Bench. This bench, being more silicified 

 than the rest of the slates, resisted erosion while the stream cut 

 down on the outside. The gravel and gold occurrence was studied 

 here, the other channels being worked out in the early seventies. 

 This small patch — the best of it being only 80 feet long by 10 feet 

 wide — was very remarkable for its richness, an area of 35 square 

 feet having produced as much as 260 ounces of gold. In some 



1 All levels taken by aneroid, both for paper and map. 



