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Knomt?rls which bounds the Boisdale hills on the south. 

 This band of Cambrian strata has a length 

 from the mouth of McLeod brook southward, 

 of about 17 miles (27 km.). In the McLeod 

 brook basin the Cambrian strata apparently 

 belong to the Bretonian (in part lower Ordovi- 

 cian) ; in the Indian brook basin, all horizons 

 of the Cambrian are represented. Along the 

 eastern side of the band-like area, the Cambrian 

 strata are faulted against the Pre-Cambrian ; 

 on the western side, in places at least, the 

 older Cambrian beds rest in an unfaulted 

 condition on the Pre-Cambrian. 



After crossing McLeod brook, the railway 

 enters a small irregular area of Carboniferous 

 Conglomerate reposing on Cambrian strata. 

 Beyond this the Cambrian measures continue 

 along the shore for a distance of about 3 miles 

 (4-8 km.) until, opposite a low projecting point, 

 they are succeeded by gently dipping red sand- 

 stones and conglomerates of the Carboniferous 

 Conglomerate series. From this point, the 

 Carboniferous measures form an almost con- 

 tinuous band of variable width extending 

 southwestward along the shore of St. Andrew 

 channel. Inland these measures underlie a 

 low, broken country abutting against the 

 steeply rising, high ridges of Pre-Cambrian 

 rocks consisting chiefly of granite associated 

 with relatively limited amounts of "felsite," 

 quartzite, crystalline limestone, etc. 



The Carboniferous strata dip in general to 

 the northwest at angles of 10° to 30°. Across 

 St. Andrew channel on Boularderie island, 

 distant about 2f miles (4-4 km.), strata of the 

 Limestone series outcrop, dipping in the same 

 general direction beneath the Millstone Grit 

 strata which, in the form of a syncline, occupy 

 the greater part of the island. The Limestone 

 series is characterized by beds of gypsum, white 

 cliffs of which are visible from the railway. 

 Rising above the hills of the island, are high 

 hills [altitude 700 to 900 feet, (215 to 275 m.)] 

 of Pre-Cambrian rocks on the mainland across 



