142 president's address — section c. 



tlie press, in consequence of a discrepancy between the first and second 

 reports of Mr. Hardman, in wliich he describes what recent observa- 

 tions have shown to be the same formation, first as Cambro-Silurian or 

 Cambrian, and later as Devonian. 



These Devonian beds of Kimberley have yielded the following 

 fossils : — Atryfa reticularis, Rhynchonella pugnus, an Orthoceras, and 

 two species of Goniatites and Spirifera. 



A feature of interest and importance in connection with these beds 

 is the evidence they afford of wide-spread contemporaneous volcanic 

 activity. This was first noticed by Mr. E. T. Hardman, in 1883 and 

 1884, who described contemporaneous dolerites, volcanic breccias, and 

 tuffs. It has beeen suggested that some of the igneous rocks occur in 

 the form of intrusive laccolites. 



In the year 1901, Mr. Gibson and I had abundant opportunities 

 of investigating these beds during six months spent in the exploration 

 of what may be called the King Leopold Plateau. Our observations 

 extended from Wyndham to Mount Hart, near Collier Bay ; the Prince 

 Eegent and Glenelg Valleys, rendered almost classical by the researches 

 of Sir George (then Lieutenant) Grey, more than 70 years ago, and as 

 far north as Admiralty Gulf. The result of the investigations indicated 

 that the staple formation was made up of a series of quartzites, sand- 

 stones, fine conglomerates, and shales, disposed in a series of broad 

 anticlinal folds. These beds extend as one continuous formation from 

 Mount Cockburn to Mount Hart, a prominent summit on the King 

 Leopold Range. Associated with the quartzites, &c., are a series of 

 bedded and intrusive igneous rocks, the prevailing types being andesite, 

 ■dolerite, and diabase. The individual characters of the different beds 

 naturally present a large amount of variation, the rocks are sometimes 

 amygdaloidal, and contain nodules of zeolites and agates. Beds of 

 volcanic ash and breccia are common in certain localities. 



In certain isolated portions of the district excellent sections are 

 exposed, showing the intrusive nature of some of the igneous rocks ; 

 the sandstones are sometimes altered into hard compact quartzite, 

 portions of which have been caught up in the body of the igneous rock. 

 Other sections indicate quite clearly that the igneous rocks have, in 

 some cases, found an easy passage along the bedding planes of the 

 sedimentary rocks, and evidently occur in the form of sills. The lavas 

 are traversed by almost vertical dykes of epidosite, which are tracable 

 across country for long distances ; whilst both the sedimentary and 

 the igneous rocks are intersected by numerous segregation veins of 

 quartz, some of considerable size and horizontal extent. 



Mr. Hardman noticed, during his explorations in 1883-4, the as- 

 sociation of fossils of carboniferous affinities with those characteristic 

 of the Devonian rocks in the Kimberley beds. Dr. Jack noticed, in 

 1906, a similar association of Devonian and Carboniferous fauna from 

 the beds near Mount Pierre, and makes mention of the carboniferous 

 limestone region, consisting partly of limestone of an older date, and 

 remarks that either there are in the Mount Pierre region separable 



