68 



flags strike W. 20° S. (dip S. 20° E. at 25°), and as the 

 road rises above the valley a distinct fault line can be seen 

 on the road that has the effect of splitting the purple shales 

 which dip at a high angle: strike of fault W. 10° S. A 

 little further on flags are seen in a washout: dip S. 20° E. 

 at 35°. 



At about 2J miles from the Wirrealpa Station, a con- 

 siderable rise of flaggy quartzites occurs, in which is situated 

 the Wirrealpa Copper Mine. The mine, which is a small and 

 new venture, is a bedded lode of shale, 2 ft. in width, lying 

 between two beds of quartzite, each being about a foot in 

 thickness: strike W. 10° S. (dip S. 10° E. at 40°). Over 

 the rise in which the copper mine is situated the country gets 

 a twist in which flags strike S. 20° E. (dip W. 20° S. at 28°). 

 This rise forms a bold scarp to the west, at three-quarters 

 o" a mile distant, where the beds are seen to gradually swing 

 round to the strike and dip last quoted. 



On the top of the next rise on the road, 3J miles from 

 the present station house, the fossiliferous (Ohollela) lime- 

 stone occurs. It is evidently the same bed as that which 

 carries Oholella in such numbers near the head station. The 

 limestone is about 5 ft. in thickness and is more solid than 

 the outcrops near the house. The fossils are found mostly in 

 the upper portions of the bed and are rare in the lower por- 

 tions. The rock is almost completely oolitic in structure, and 

 while it carries a diversity of organic remains it is particu- 

 larly characterized by the presence of the brachiopod Oholella. 

 Slabs can be got which are formed by one mass of the valves 

 of this shell: strike of the bed W 20° S. (dip S. 20° E. 

 at 15°). 



About 150 yards across the valley, to the northward, 

 another limestone makes a prominent outcrop. This is the 

 limestone which accompanies the Oholella limestone near the 

 head station. It is known as the "ridge" limestone, or the 

 "5-mile ridge," as it makes a prominent feature across the 

 country for 5 or 6 miles. This ridge limestone and the 

 Oholella limestone cut the road at a right angle. 



Following the fossiliferous limestone westward, the beds 

 cross the Wirrealpa Creek within a few hundred yards of the 

 road, with a strike W. 20° S. and dip S. 20° E. at 20°. 

 Shortly after crossing the great creek the beds swing round 

 sharply to S. 20° W. and dip E. 20° S., passing under the 

 escarpment of red sandstone, mentioned above, which is the 

 same range in which the copper mine is situated. 



Returning to the road I followed the outcrops of the 

 fossiliferous beds in an easterly direction. Here the dip 

 swings round to the south, then S. 20° W., then S.W. at 23°. 



