﻿452 Canadian Record of Science. 



ment of a paper by Mr. A. J. Rossi, of New York, on the smelting of 

 Titaniferous Iron Ores. The latter is very important, as the areas 

 occupied by tlie anorthosites contain enormous masses of iron ore of 

 this cliaracter. 



The map which accompanies the report comprises an area of 3,258 

 square miles, including parts of the Counties of Argenteuil, Terre- 

 bonne, Montcalm and Joliette, in the Province of Quebec. 



The coloring of the map is very distinct, the areas of the several 

 rocks being easily distinguished ; this is also aided by letters and 

 abbreviated words. The strike and dip of the rocks, as well as the 

 localities which contain deposits of economic minerals, are indicated by 

 the usual geological signs. The influence of the strike of the rock on 

 the natural features of a country is important, and especially well 

 shown in the course taken by the River L'Assomption, and in the 

 formation of Lac des lies, the forks of Lac Ouareau, and others. 



The topographical features are as minutely shown as the scale of four 

 miles to the inch Avould permit ; also tlie roads and railway lines, so- 

 that to anyone interested in this district, especially those who have 

 enjoyed the Natural History Society's field days, in this section of the 

 country, the possession of such a map would be extremely useful. 



On examining the map it is seen that occupying the south-east corner 

 are the Paheozoic Rocks of the Cambrian age, under which the 

 Archaean dips. One small area of Cambrian which has escaped the 

 destructive agency of erosion is situated in the township of Aber- 

 crombie. The country surrounding it affords this interesting fact of 

 scientific value, namely, that where the Cambrian has been but lately 

 removed from the Archtean hills, they have the same characteristics as 

 other and longer exposed hills, so showing that it must have been a 

 pre-Cambrian erosion which gave them their present shape. 



In the centre of the sheet, and a little to the west, lies the great intru- 

 siv^e mass of Morin anorthosite, which has an irregular circular outline 

 and an area of 990 square miles. It is surrounded by the Laurentian, 

 the strike of which coincides with the outline of the )nass except in the 

 south-east, where the mass develops an arm-like extension and passes 

 under the Palaeozoic. 



There are two large intrusions of acid rock, a granitic in the north- 

 east of the sheet and a syenitic in the south-west. 



The Laurentian occupies the rest of the map, with the exception of 

 a few minor intrusions of anorthosite. 



Three railways traverse this district, so tliat, considering the extreme 

 ruggedness of the country, the travelling facilities are very good. The 

 Canadian Pacific Railway, branching from the main line at St. Martin's 

 Junction, runs over the Palaeozoic almost to St. Jerome, then across 

 the Laurentian to Piedmont ; from thence it crosses the Morin anor- 

 thosite to Morisson's Station, and then unto tlie Laurentian again. Ita 



