Organic Remains in Fundamental Gneiss of Sweden. 173 



5. From the above we are warranted in coming to the conclusion 

 that the Green Slates and Porphyries of the Lake-district are super- 

 imposed unconformably upon the series of the Skiddaw Slates. 



Addendum. — Since the first part of this paper was published, I 

 have found a single small section between the Yale of St. John and 

 Keswick, in which the upward termination of the Skiddaw Slates is 

 exhibited. This occurs about two miles to the S.E. of Keswick, 

 close to the high road to Ambleside, near a place called Dale- 

 bottom, in the valley of Naddle Beck. Here a small stream flows 

 down from a hill called the Pike, and exhibits in its lower portion 

 a small exposure of the upper shaly beds of the Skiddaw Slates, 

 which dip S.S.E. at 50°, and are directly overlaid by the fine-grained 

 felspathic trap, which forms the base of the G-reen Slate^. 



itTOTiOES oip I!vd:E:M:oII^s. 



I. — On the Existence of Eocks containing Organic Substances 

 IN THE Fundamental Gneiss of Sweden. 



THREE papers relating to the occurrence of certain vegetable 

 substances in the Fundamental Gneiss of Sweden, have recently 

 been communicated to the Eoyal Academy of Sciences at Stockholm.^ 



The first of these papers, by M. Igelstrom, which describes some 

 beds of bituminous gneiss and mica schist that occur interstratified 

 in common reddish granite-gneiss at the western part of the high 

 and precipitous Nullaberg, was noticed in the Geological Maga- 

 zine, Vol. IV. (1867) p. 160. 



M. Igelstrom considers that the Gneiss and Mica Schist of the 

 NuUaberg must be ranked among the Sedimentary and Fossiliferous 

 Strata. 



In the second paper M. Nordenskiold points out the principal in- 

 gredients in these bituminous rocks of Nullaberg, — they are a 

 greyish-white orthoclase and silver- white mica, mingled with vari- 

 able portions of a carbonaceous or coal-like substance. This car- 

 bonaceous substance is very brittle, and the rock is therefore more 

 friable than common gneiss. The grains of orthoclase break along 

 the cleavages of the felspar, and the fracture of the rock is thus 

 crystalline. 



He regards the rock as probably due to the solidification and 

 crystallization of a clay-like sediment, consisting of organic sub- 

 stances and inorganic matter, of the same constituents as the common 

 felspar ; and he remarks, as a phenomenon not at all improbable, 

 that a change in the relative position of the atoms, i.e. a crystal- 

 lization in a solid mass tending to a disposition of its molecules, 

 according to the best conditions of equilibrium, took place without 



^ L. J. Igelstrom, On the occurrence of thick beds of bituminous gneiss and 

 mica schist in the JSuUaberg, parisli of Ostmark, province of "Wermland, in Sweden. — 

 A. E. Nordenskiold, Note ou the mineral character of the rock. — F. L. Ekman, 

 Chemical analysis of the rock. — Translated from communications read to the Eoyal 

 Swedish Academy of Sciences at Stockholm. 



