these beds to tremendous lateral compression, by whicb tbej 

 were thrown into a series of folds, the culminating point being 

 Mount Horrocks. In the immediate neighbourhood of Auburn 

 the foliation is clearly displayed by the road cuttings. Eour 

 miles eastward the Pine Creek has worn its channel com- 

 pletely through the slates of the upper group down to the 

 crystalline limestone of the "lower group." The exposure of 

 limestone at this point was observed by Prof. Selwyn in 1859, 

 when driving from Saddleworth to Auburn. A few yards to 

 the westward is a dyke of dolerite, which is the only eruptive 

 rock I have observed in this district, but I am informed that 

 fragments have been found in the Skilly ranges, near Clare, 

 b}^ Professor Tate. Professor Selwjn records the occurrence 

 of a granite dyke at the confluence of the Julia and Eiver 

 Light, about four miles south of the section. At Pine Creek 

 this rock is quarried for road metal. 



Between Eiverton and E-hynie some of the weathered boul- 

 ders of marble become deeply stained with iron oxide, and have 

 a suggestive coralline appearance, and when an unweathered 

 fragment is ground smooth the mass is seen to be composed of 

 shot-like concretions cemented together. Specimens of this 

 rock have been submitted to Prof. Tate and the G-overnment 

 G-eologist, but were not recognised as organic formations. The 

 same rock is traceable as far south as Stockport, beyond which 

 the rocks disappear beneath Tertiary deposits ; but at Templers, 

 nine miles from Gawler, the debris from the well is talcose 

 slate, similar to that found in other places occupying the 

 highest position in the " lower group" series. The Alma plain 

 is loam and drift resting on rocks of the " upper group," and 

 is bounded on the west by the low Dalkey Eange. At Stock- 

 yard Creek the wells show talcose slate as at Dry Creek, west 

 of Tarlee, The dip is easterly, and passing west to the "Wil- 

 derness Creek, near Owen, there is an exposure of the lime- 

 stones, also dipping east. Seven miles north of this, where the 

 Wakefield Eiver forces its way through a gap on to the Wake- 

 field Plains, the sequence of the rocks is again observable in 

 the natural section there formed. This Dalkey Eange, though 

 much lower in altitude, is the counterpart of the Alma Eange 

 on the east — a base of Primary rocks capped with Tertiary 

 sandstone. The beds of the " upper series" resting between 

 those two ranges show much false bedding, and along the Her- 

 mitage Creek — under the flank of the thick quartzites — are 

 distinctly inverted. 



Stockyard Creek is the most southern point of the " lower 

 group" in Dalkey. The rocks of the upper group seem to flank 

 it on the east and south, while Tertiary deposits bound the 

 western side. The channel of the Light from Hamley Bridge 



