82 



Notes on the Geological Features of the 

 Teetulpa Goldfields. 



By H. Y. L. Beow.>^ F.a.S. 



;Kead Aprils, 1887.1 



These fields are situated in the north-east district of the pro- 

 vince, and are about 200 miles from Adelaide in a direct line. 

 In its general appearance the country is uninteresting. The 

 hills are low and undulating, aud but few trees of any kind 

 grow upon their slopes. They are covered, together with the 

 flats and plains that lie between, with saltbush and bluebush. 

 The few trees growing in the neighbourhood are, for the most 

 part, sandalwood, and occasionally mallee. 



The country is covered with a yellow loamy clay of varying 

 thickness, and quartz fragments. The quartz is derived from 

 the reefs and blows, with which the neighbourhood abounds. 



The Primary rocks consist principall}^ of undulating faulted 

 strata of clay- slate, calcareous clay-slate, limestone, and clay- 

 slate conglomerate. Their strike is, for the most part, east 

 and west, and they are much jointed and cleaved in the same 

 direction. 



The cleavage is at vertical and high angles, and almost entirely 

 obliterates the bedding This makes the rocks appear to dip at 

 high angles. The bedding, may, however, be generally detected 

 by the different colours and hardness of the rock. 



]S'o fossils have been found, but the age of the rocks is the 

 same as those of which the main ranges to the southward are 

 composed. They are, in fact, a continuation of those ranges. 



In places the clay-slate is a conglomerate, for boulders and 

 pebbles of granite, quartzite, sandstone, and other silicious 

 rocks are scattered through it in greater or less numbers. 



There are no defined dykes of igneous rock visible on the 

 surface, but in some places decomposed micaceous veins have 

 been met with. It is probable that as the country is underlaid 

 by granitic and gneissic rocks, the igneous rocks occur to a 

 greater extent at lower depths. 



Quartzite and sandstone beds are interstratified in places, 

 but, comparatively speaking, they are not so frequent and per- 

 sistent as in other parts of the surrounding districts. 



Eastward, towards the Weekeroo and Bumbumbie Eanges, 

 these strata are underlaid by gneissic rocks, quartzites, mica 

 .schists, and metamorphic granite. These have a more or less 



