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drainage of North-Eastern Munno Para, North- "We stern Para 

 Wirra, and South- Western Barossa, through this numerical 

 reducing and thinning-out to the north of the Munno Para 

 quartzites, finds a comparatively easy outlet to the west. On 

 the other hand, it will be seen that the quartzites intersect 

 the modern watercourses bounding the district on the south- 

 east and south. Thrice had these drainage waters to contend 

 for mastery with the quartzites ere they succeeded ix pene- 

 trating the stony mass. 



I may here state, from the nature and geological structure 

 of the Para and southern Munno Para hills, that in early 

 geological times the drainage of Gould's Creek, Little Para, 

 and adjoining regions was carried off by way of Golden 

 Grove and Modbury, meeting the waters of the then Southern 

 Ocean, probably not far from where the City of Adelaide now 

 stands. 



Upland Miocene. 



Description of Strata. — These beds attain no great thickness 

 throughout the district, and the bedding may be said to be 

 somewhat indistinct; nevertheless, what still remains, in 

 descending order, can be read as follows : — 



The Upland Tertiaries of Munno Para consist chiefly of soft, 

 fine-grained, friable sandstone. The silicious materials fre- 

 quently held together by an argillo-calcareous paste, not 

 unfrequently impregnated by infiltrations of iron oxides. 

 Though such be the general characteristics of the formation, I 

 have not unfrequently found the basement consisting of one 

 or more of the three following description of beds : — (1.) 

 Angular fragments of quartz and other rocks (which might be 

 termed a breccia), held together by a ferruginous paste. (2.) 

 Though less common, conglomerates, in the true sense of the 

 term, in some cases held together by a cement of argillo- 

 calcareous material ; in others, as in the case of the breccias, 

 by ferruginous matter. (3.) Most commonly, however, the 

 basement of the deposits consists of mottled argillaceous sand 

 rock, evidently the characteristic sandstone in a high state of 

 decay. 



Range of the Formation. — The Upland Miocenes of Munno 

 Para constitute a group of outliers, scattered chiefly over the 

 higher tracts of the district. But these isolated patches are to 

 the geologist of significant meaning, as each of them, when 

 systematically arranged, becomes an integral part of an intel- 

 ligible language, and though time no doubt has wrought sad 

 havoc in defacing the surface outlines of the country since the 

 period when the deposition of these beds terminated, yet suffi- 

 cient still remains to indicate that they once overlaid pretty 



