Reviews — Prof. E. W. Skeats — Nepheline at Omeo. 319 



of Science for March, 1913, have done good service by collecting and 

 critically discussing the available data. They point out that a non- 

 uniform pressure, i.e. one involving a shear, is an incomparably more 

 effective agency than a uniform pressure, which is not so important 

 as a high temperature. 



YIII. — Ojs" the occurrence of jS^epheline in Phonolite Dykes at 

 Omeo. By Professor E. W. Skeats. Section C : pp. 126-31, 

 with one plate. Australasian Association for the Advancement 

 of Science, 1912. 



THIS paper gives a list of previous records of felspathoids in 

 Victoria, and shows that most of these have been due to incorrect 

 determinations. The author corrects his previous record of nosean 

 and melilite in the alkali rocks of Mt. Macedon. 



A brief sketch of the geology of Omeo, Eastern Gippsland, is given. 

 Granites and quartz-diorites. are intrusive into pre-Ordovician or 

 pre-Cambrian schists, and there is a group of anorthoclase-trachytes 

 and solvsbergites, which are younger than the plutonic rocks. Another 

 group of dykes occurs at Omeo, and the phonolite dykes here described 

 are the youngest in this area. 



The rocks are described in detail, and the percentages of alkalies 

 in one rock have been determined. The mineral composition is : 

 soda-orthoclase 46, nepheline 28, and segirine 25 per cent. A mineral 

 occurring interstitially between the felspars is referred provisionally 

 to cancrinite. 



IX. — Canada. 

 Geological Survey of Canada. 



(A) In Memoir ]^o. 17e (1912) is an account of the "Geology 

 and Economic Hesources of the Larder Lake District, Ont. ", 

 by Mr. M. E. Wilson. The formations shown on the map are 

 Keewatin (greenstone and various schists, slate, dolomite, quartz- 

 porphyry, and rhyolite), Pontiac schist, Laurentian (granite, 

 gneiss, etc.), Huronian (conglomerate and greywacke), Post Lower 

 Huronian (diabase, etc.), and Pleistocene and Pecent deposits. The 

 mineral products include gold, silver-lead, copper, cobalt, nickel, 

 molybdenite, and iron. The report contains interesting views of 

 scenery and rock-sti'uctures. 



(B) Memoir I^o. 35 (1912) gives the results of a "Reconnaissance 

 along the National Transcontinental Railway in Southern Quebec ", by 

 Mr. J. A. Dresser. The rocks described include Cambrian, Ordovician, 

 Devonian (igneous), and Drift. The district has been glaciated from 

 the IS'.N.'W., and the rock surface is generally, and in places 

 heavily, covered by soil. Stratified Drift deposits of clay, sand, 

 and loam occur in the lowlands and in some of the upland valleys. 

 The minei'al prospects are not of great promise. Small quantities of 

 asbestos, chromite, chalcopyrite, and bog iron-ore occur ; there is 

 slate of good quality, also quartzite, and peat-bogs. Much of the 

 district is suitable for farming, and part for lumbering. Among the 

 illustrations there is a striking view of the St. Lawrence lowland. 



