6 PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [June 3, 



lies m the low promontory to the N.VV. By passing, however, 

 along the granitic escaipment and by tracing the junction of that 

 rock with the sedimentary strata, we saw that such an interpreta- 

 tion was fallacious. 



The dip is there found to vary according to the form of the masses 

 of granite against which the beds of limestone abut; and by fol- 

 lowing these beds to the N.E. it is at length clearly seen, that the 

 granite has been irregularly thrown up against the edges of different 

 beds of limestone which have been folded and contorted around the 

 intrusive rock in different directions. We also observed, that in- 

 stead of passing under the sandstone, the limestone was cut off" by a 

 line of fault parallel to the granitic scarp, which so ranges athwart 

 the isle as to come up to the limestone on the N.E. shore of the 

 isle. This fault probably ranges downwards into those bituminous 

 schists (lerskiff^er) which in so many parts of Sweden lie beneath 

 the Orthoceratite and Sphseronite limestone, and surmount a sand- 

 stone which is the fundamental Silurian rock in all other tracts of 

 Sweden where the strata lie undisturbed (the Slepsten or whetstone 

 of Dalecarlia). One or two small quarries of this whetstone are 

 visible in the low grounds, and it is, as elsewhere, a fine-grained 

 whitish and yellowish sandstone with a few flakes and patches of 

 green marl. Though much traversed by diagonal joints, the strata 

 present no other appearance of inclination or disturbance ; for the 

 quarries lie at some distance from the granite. 



The transverse section (PL I. fig. 2) suflSciently explains the 

 relations of the rocks in the isle of SoUer. 1st, the sandstone (a) is 

 the same which almost invariably underlies the bituminous schists 

 in other provinces of the kingdom ; 2nd, the place of the bituminous 

 schists is occupied by a fault, indicated by a line of morass, peat, 

 bog and water; 3rd, the red Orthoceratite limestone and the grey 

 Sphseronite rock (c and c*) really form the uppermost strata of this 

 isle, the granite having been irregularly upheaved through them. 



In following the Lower Silurian limestone northwards to Orsa, 

 the red Orthoceratite beds are seen at Watnas in a vertical and 

 highly elevated position, striking N.E. or N.N.E. and S.S.W. This 

 calcareous ledge, rising out from beneath a gradual slope of detritus 

 towards the lake of Orsa on the west, is succeeded on the east by 

 many rolled fragments of conglomerate and porphyry. On ascend- 

 ing however to the hill top or ridge of the Degeberga, we observed 

 in a rugged mountain road (and for more than an English mile) a 

 succession of peculiar strata whose strike was conformable to that of 

 the Orthoceratite limestone, and also highly inclined (see Plate I. 



Some of these beds (^) are undistinguishable from quartz rocks ; 

 others resemble highly crystalline hard red sandstone; others, again, 

 might be mistaken for what would usually have been called grau- 

 wacke grits and fine conglomerates, the whole being more or less 

 thin-bedded and containing some strata passing into cherty and flinty 

 masses, and others into hornstone, &c. These highly inclined and 

 altered beds are thrown off" by syenitic granite (q), which seems to 



