GEOLOGY. 245 



the tertiary period, composed of pebbles, of gravel, and of 

 clay mixed with sand, which surround the interior of 

 the country, mark the limits of successive masses of these 

 glaciers ; they are probably moraines, formed on one hand 

 by gravel deposited by the glaciers, and on the other by 

 the action of the waves of the sea. The most remarkable 

 of these chains is that which forms the environs of the 

 town of Joensuu, stretching in a curve along the south and 

 south-east shores of the lakes of Karelia and Saima to 

 Lahtis, at the southern extremity of the basin of the 

 Paijanne, whence it turns to the south-west, and termin- 

 ates near the promontory of Han go. It well merits the 

 name given to it, Salpausselka barrier or enclosure, for 

 it appears as a dyke to the lakes of the interior, the waters 

 of which have not succeeded, except in two narrow passages 

 that at Imatra, and that at Keltis, on the Kyminene to 

 wear away a passage to the sea. Another similar chain, 

 parallel to that mentioned, but smaller, and more frequently 

 interrupted by lakes and rivers, runs a little further to the 

 north by Kesaelaks, Parikkala, the islands and promontories 

 of Lake Saima, Savitaipal, and thence, always holding west, 

 to Anianpetol. It is thus beyond contradiction a terminal 

 moraine marking the limit of the glaciers after a second 

 recession. Other chains of a similar character in the 

 interior of the country, the formation of which is due, 

 according to all probability, to the action of the water pro- 

 ceeding from the ice-sources, have a direction, for the 

 most part, from the north, north-east, and the north-west, 

 towards the south, south-east, and the south-west ; it is in 

 like manner the case that the lakes of the interior stretch 

 in this direction, and that in this direction are disposed 

 the stratifications of the ground.' 



Everywhere in Finland may be seen rocks rounded, 

 smoothed, and marked with striae, minute parallel scratch- 

 ings. Two theories have been advanced in regard to the 

 production of these elsewhere, which are no less applicable 

 to the phenomena presented by the rocks in Finland. 



