Sketch of the Geology of Northern Europe. i7 
in the mountains of Lapland, and at their bases, fine white sand 
im patches, and black and grey slate, quartz, and sandstone are 
found.* 
On the Pargas islands in lat. 60° N. in the gulf of Bothnia are 
long steep ridges of gneiss, crowned with birch and fir trees. On 
one of the principal islands is found the mineral called pargasite, 
which occurs in large veins of milk-white limestone, and traverses 
the island from side to side. The structure of this limestone is not 
sufficiently fine, to be called marble, but it is variegated with clouds of 
beautiful yellow, and waves of grey, and contains irregular veins of 
augite and hornblende rock. Bright purple spots supposed to be 
fluor, and moroxite, coccolite, and romantzovite, occur in some of 
its varieties. Tourmaline is sometimes, though not often seen. A 
remarkable mmeral found in this rock, is chondrodite. It is so much 
harder than the limestone in which it is imbedded, that the latter wash- 
ing and wearing away by the weather, leaves it in orange colored, 
and yellow knobs, and protuberances, on the surface, while if adheres 
in points, or clings in masses, to a limestone centre. It is also found 
inmany partsof Finland, always in primitive limestone, passing through 
gneiss. Gneiss, more or less distinctly foliated, forms the common 
rock of the country, on the adjacent continent. ‘The rock of Abo 
is an exception, being an example of stratified fine grained granite, 
very hard, studded with garnets. North and east are granitic slates ; 
rose quartz; felspar; copper ore ; garnets ; and primitive limestone. 
Primitive granitic slates continue northeasterly, and form the rap- 
ids or falls of Imatra, “one of the grandest spectacles of thenorth.” 
A fine deep black slate is quarried near Lake Ladoga, “where is 
found a garnet rock,” and further north is a species of potstone wii 
which are made bowls and various utensils. 
South of this tract, the primitive rocks lose their lamellar structure, 
and a true granite prevails. Felspar, spotted with smal] grains and 
erystals of hornblende, and black mica, predominates in the granite 
opposite Borgo, and rolled masses occur near Petersburg. Between 
Borgo and Louisa, are found bowlders of jet black mica slate, with 
and without garnets, and a red and yellow hornstone- As far as the 
granite is found in situ, it is particularly marked by oval and round 
masses of reddish felspar. Hornblende is plentiful, and mixed with 
* Ehrenmalm’s Travels. 
Vout. XVIL—No. 1. 
