1846.] MURCHISON ON THE GLOLOGY OF SCANIA, ETC. 33 



4. Silurian Eocks of Scania. 



The lowest Silurian rock of Scania, as in other parts of Sweden, 

 is a sandstone. In parts north of Andrarum, referred to by Pro- 

 fessor Forchhaininer, it is seen in contact with the granitic and 

 gneissose rocks, on which it rests ; an order which is also exposed 

 in the adjacent isle of Bornholm, described by that author. In our 

 traverse from Andrarum to Lund, we could only detect this sand- 

 stone appearing at one or two spots, without visible relations to any 

 other rock. At Andrarum, however, we were abundantly satisfied 

 with the fine exposure of the next overlying band or alum slate*, 

 which is there a jet-black, finely laminated schist, wholly devoid 

 of slaty cleavage and disposed in horizontal beds. Being largely 

 charged with sulphuret of iron, these schists are broken up for the 

 extraction of alum. Some of the beds are slightly calcareous, and 

 contain at intervals concretions both large and small of an earthy 

 dark limestone, which are occasionally not less than three feet in 

 diameter and of flattened cheese-like forms. Where this concre- 

 tionary action has taken place, the pyrites is often collected into 

 groups of crystals. 



The most abundant fossils are the Olenus paradoxides and the 

 Battus pisiformis ; the latter being the same species which occurs 

 in the British Lower Silurian rocks, whilst the former occurs in the 

 alum slates of Kinnekulle and other parts of Sweden. 



The section, PI. I. fig. 13, explains the general relations visible in 

 passing across this tract from east to west. 



Traversing the country westwards from Andrarum through Val- 

 larum and Fremminge, over undulating plains and low plateaus co- 

 vered with detritus and boulders, it was only at rare intervals, and 

 in a ravine or two, that we could detect the outcrop of other mem- 

 bers of Silurian rocks ; but whenever they did appear it was in the 

 form of shale and schist, occasionally with Graptolites, but without 

 limestone. In fact, we were assured by Professor Forchhammer, 

 and M. Marklin of Upsala, who have sedulously examined this 

 country, that the great limestone, with remains of Asaphus and 

 Orthoceratites, so abundant in all other parts of Sweden where Lower 

 Silurian rocks occur, has no existence either in Scania or in the island 

 of Bornholm ; the whole of the lower group being there represented 

 by sandstone and schists, the latter containing some traces of 

 black limestone. These schists however, though not divided by the 

 Orthoceratite limestone (which appears to have thinned out), are 

 characterized in their upper part by Graptolites, and in their lower 

 by Trilobites, Agnostus, &c. At length we emerged from the 

 monotonous region of mud (derived from the decomposition of these 

 Lower Silurian schists), and at Bielo-gaard we fell in with the first 

 limestone visible. From the aspect of this rock and its imbedded 

 fossils, it was evident that we had reached a true Upper Silurian 

 rock, since it contained forms of Avicula, Spirifer and serpuline 



* As there is no cleavage in these rocks, the term " alum schists" or " almn 

 flags" would he a more correct term than ** alum slate." 



VOL. III. — PART I. D 



