30 Reviews — Geological Surveij of South Australia. 



and Tertiary area into this colony from New Sontli Wales and 

 Queensland was proved along a distance of 225 miles of boundary of 

 the former, and 300 miles of that of the latter colony. 



The sketch map and sections accompanying the report are intended 

 to show approximately the boundaries, thickness, and stratigraphical 

 positions of the older mineral-bearing and the Secondary and Ter-^ 

 tiary rocks. The latter are provisionally classed as of Cretaceous 

 age, pending the obtaining of further information from fossils and the 

 discovery of older underlying beds over any portions of the area. 

 The ages assigned to the older rocks are in accordance with their 

 similarity in composition and position to certain rocks in New South 

 Wales. 



"The following is a general list of the rocks referred to in this 

 report, in descending order, with their ages provisionally : — 



1. Tertiary. — Sand, clay, gravel, and conglomerate ; gypsum and rock salt. 



2. Cretaceous. — Table-land formation, sandstones, kaolin, grit, and conglomerate ; 



clay and sandy beds with gypsum, ironstones, sandstones, 

 limestones, and calcareous clays in horizontal beds. 



3. Devonian (?). — Clay-stones, and conglomerates skirting the Flinders Eange and 



elsewhere. 



4. Silurian (?). — Limestones, clay-slates and shales, quartzites, calcareous slates, 



sandstones, siliceous and conglomeratic limestones. 



5. Metamorphic. — Clay-slates, mica-slate, and schists with granite dykes. 



6. Granite and greenstone." 



Fossils do not appear to have been commonly met with. But at St. 

 Mary's Pool, in the bed of the MacDonnell Creek, " On some of the 

 hard blocks of quartzite and quartzose sandstone near this place, 

 there are marks somewhat resembling the impressions of the feet 

 of human beings, kangaroo, birds, etc., which are considered to be 

 fossil tracks. On examination they appear to be merely rough 

 imitations of such, the smooth surface of the rocks having been 

 removed by some hard instrument to a slight depth, the pitted marks 

 of such action being plainly visible. Besides this, in one case, the 

 plane of the supposed impression is at an angle with the planes of 

 bedding of the rock." 



" The general direction of strike of the main line of quartz reefs 

 at Waukaringa is about E.N.E., and the dip southerly, at an angle of 

 from 25 to 35°. The thickness of these reefs varies from a few 

 inches to about 20 feet ; the quartz is as a rule of a highly ferruginous 

 character, and associated with iron ore and a ferruginous gossany 

 formation. The veins occur in and between bands of quartzose 

 sandstone, quartzite, sandstone, clay and calcareous slates, which 

 form synclinal and anticlinal curves and undulations, and are highly 

 jointed and cleaved. 



"Eichman's line lies further south, and strikes N. 53° E., with a 

 north-westerly dip of from 35 to 55°. The character of the quartz 

 and the bed rock are similar to the main line of reef. 



" Blackfellow's reef to the north-west of the above line is said to 

 have yielded the coarsest gold yet found in this locality. The vein, 

 which is very thin, consists of quartz with carbon9,te of iron, iron 

 pyrites and oxide of iron in greenish clay, slate, and argillaceous 

 sandstone. These lines of reef outcrop towards the summit of low 



