57 



hill west of South Blinman, and also west of the Blinman 

 Mine. 



THE BLINMAN CREEK. 



The Blinman Creek, near the townships of North and 

 South Blinman, supplies exposures illustrating crush-rock to 

 an extreme degree. The purple shales, particularly, are con- 

 verted into crush-breccias and crush-conglomerates in which 

 the original bedding is entirely obliterated, or is present only 

 in isolated fragments. The locality is also greatly inter- 

 sected by intrusive dykes. 



Going south from South Blinman (in creek) the purple 

 shales are overlain by flaggy shales: dip W. 10° S. at 80°. 



(1) A great basic dyke crosses the creek forming a pro- 

 minent ridge 30 ft. in heiglft and 100 ft. in width. The 

 dyke cuts across cupriferous flaggy shales, the latter having 

 a dip of 70° W. of N. at 60°. 



(2) Two hundred yards lower down the creek another 

 dyke crosses the stream — on the eastern side, measuring 15 ft. 

 in height and 90 ft. in width. On the southern side of the 

 •dyke purple shales form a cliff face in the creek and are 

 intensely broken and brecciated. The dyke crosses to the 

 western side, where it is seen on the rise of the hill. The 

 strike is N.E., and follows along the slack ground. 



(3) On the western side of the creek, about midway 

 between the two dykes just referred to, is a circular outcrop 

 of Igneous rock, 100 yards in circumference. The stone is 

 scoriaceous, in parts; whether the vesicular structure is due 

 to gas cavities, or spaces left by the decomposition and removal 

 of included crystals, is not quite clear, but the cavities have 

 been subsequently filled, in some instances, with Fe CO3 and 

 other crystals. Tlie circular outline of the outcrop suggests 

 the possibility of its being an old volcanic "neck." 



The prominent hill that is on the western side of South 

 Blinman has quartzites at its summit, and, for the most part, 

 on its southern face also: dip 10° S. of W. at 75°. The 

 quartzite carries dark lines (a common feature in the quartzites 

 of the Upper Cambrian series), and there is also a dolomitic 

 limestone, much contorted and irregular, that outcrops on 

 the southern and south-eastern flanks of the same hill. The 

 dolomitic bed has a rolling strike of N.W. and S.E. 



A ridge of hills runs parallel with the road between South 

 Blinman and North Blinman, on the eastern side, consisting 

 of flaggy shales and quartzites, with dip N.E. at 75°. 



Following the Blinman Creek to North Blinman, a great 

 development of crush-rock occurs both in the creek and on 

 the flanks of the low ranges on the western side. The rocks 

 consist of siliceous shales and thin dolomitic timestenes, in 



