Geology and Natural History. 239 



areas of pre-Carboniferous granite and gneiss. The relations and 

 character of the formations near the coast line are revealed by a 

 3011 foot well at Carnarvon, which shows 1211 feet of Mesozoic, 

 1650 feet of Carboniferous. The Carboniferous section in the 

 Arthur River valley consists of (l) grits and tine conglomerate, 

 (2) fossiliferous limestone, (3) limestone conglomerate, (4) gla- 

 cial bowlder bed, (5) sandy and flaggy limestones. This glacial 

 bowlder bed is well exposed at a number of localities and in the 

 Wyndham River valley contains Spirifera, Productus, Polyzoa, 

 and Aviculopecten. The Carboniferous series as a whole rests 

 upon metamorphosed sedimentary rocks of unknown age. Owing 

 to the economic importance of this part of West Australia some- 

 what detailed studies of structural relations were made. In the 

 vicinity of Bangemall slates, limestones, quartzites and diabase 

 are arranged in a denuded anticlinal fold and are intersected by 

 numerous quartz reefs. Mount Augustus, one of the most con- 

 spicuous scenic features of West Australia, was found to be a 

 sharp monoclinal fold of schist and conglomerate. Both normal 

 and thrust faulting are revealed at Coorabooka Gap, and the 

 position of this gap as well as the arrangement of the drainage 

 lines suggests interesting physiographic studies. In the Uaroo 

 copper district of Ashburton the rocks are sedimentaries of 

 unknown age and have undergone deformation since mineraliza- 

 tion. 



A chapter on petrography by J. Allan Thomas contains a dis- 

 cussion of dolomite and cherts, pyroxenites and amphibolites, 

 together with conclusions regarding magmatic sequence. Sixty- 

 nine slides are described in detail accompanied by a list of eighteen 

 analyses. While this bulletin is chiefly devoted to economic 

 studies, it adds considerable to the meager information regarding 

 the geology of this interesting country. 



Bulletin 38, The Irwin River Coalfield ; by W. D. Camp- 

 bell. 1910. Pp. 101, 7 plates and 53 figures. — The pre-Car- 

 boniferous rocks of the Irwin River district are gneisses and 

 granites "traversed by dikes of diabase, basalt, and norite, and 

 lodes of lead and copper in addition to quartz veins." This 

 crystalline complex was greatly eroded before the deposition of 

 extensive beds of quartz conglomerates and submarine tuffs of 

 pie-Carboniferous age. The Carboniferous rocks are fossiliferous 

 and consist of clays, shales, sandstones and limestones. One 

 important stratum is the glacial bcjwlder bed which has been 

 recognized at several localities in Western Australia. In the area 

 under discussion this bowlder bed is found within the Carbonifer- 

 ous and not at its base. Jurassic strata, 300 feet in thickness and 

 containing lignite, rest upon the denuded surface of the Car- 

 boniferous. Tertiary limestones and sandstones seems to overlie 

 unconformably the Jurassic rocks of the Hutt River district. 



H. E. G. 



9. Paleeontological Contributions to the Geology of Western 

 Australia. Geol. Surv. Western Australia, Bull. 36, Pt. Ill, 

 pp. 133 and 12 pis. 1910. — A series of eight papers is here 



