564 Bevieics — Geological Map of North America. 



a standard. There can be no doubt that Sheet I represents the 

 results of long-continued and brilliant geological investigation. 



The present map, which is on the scale of about 3'7 miles to the 

 inch, includes Cape Town and its well-known suburbs ; the towns 

 of Robertson, Ladygrey, Caledon ; and the coastline from a little 

 north of Cape Town to within ten miles of Cape Agnlhas. The 

 farms are named and their boundaries represented. Heights are 

 unfortunately few and far between — a serious omission on a map on 

 which the mountain ranges are only indicated by a name written 

 along their general trend. 



The geological formations represented by colour extend from the 

 Malraesbury Series to the Uitenhage Series, the superficial deposits 

 being uncoloured. The intrusive rocks are shown by two colours, 

 one for the dolerites and diabases and another for the quartz 

 porphyries and granites intrusive into the Malmesbury Series. The 

 colours throughout are clear and distinctive, and bring out the 

 structure at a glance. 



The alterations from maps published previous to the work of the 

 Commission include the representation of a series of grits, arkose, 

 and conglomerates — French Hoek Beds — probably newer than the 

 Malmesbury Series and certainly older than the Table Mountain 

 Sandstone. The Witteberg Series are separated and coloured 

 distinctively from the Table Mountain Sandstone. This clearly brings 

 out the structure of the folded regions. A considerable area of the 

 Dwyka Series and Ecca Series is shown on the downthrow side 

 of the Worcester-Robertson Fault. The Enon Conglomerate is 

 definitely correlated with the Uitenhage Series. 



It is nowadays demanded of a Geological Survey that it should be 

 of economic value. In questions of water supply from underground 

 sources, irrigation works, and agriculture, the present map is 

 patently of service. It is not, however, so generally known that the 

 systematic geological survey of Cape Colony has yielded results of 

 fundamental importance in determining the geological succession of 

 the neighbouring, and, from a mining point of view, more favoured 

 colonies. In this respect it is not altogether gratifying to learn that 

 the work of the Cape Geological Surveyors is more keenly watched 

 and more highly appreciated abroad than in this country. 



While engineers will naturally make use of these maps, no 

 geologist, claiming to be cosmopolitan in his aims, can neglect the 

 structure so clearly illustrated in the geology of Cape Colony. 



The map is unpriced. 



III. — A New Gkological Map of North America. 



AT the meeting of the Tenth International Geological Congress 

 in the city of Mexico, on September 6th, copies of a new 

 geological map of North America were distributed to the members 

 present. It is accompanied by a descriptive text written by 

 Mr. J. G. Aguilera, " Aper^u sur la geologie du Mexique pour 

 servir a I'explication de la Carte geologique de I'Amerique du 



