568 KEroET— 1889. 



carbonaceous, and pyrltous, like the alum-slates of Southern Norway. From some 

 of these bands graptolites are reported to have been obtained further to the 

 south-east. The whole of this great series of rocks is fouud to be progressively 

 more crumpled and crystalline as it is followed southward, until it becomes essen- 

 tially a group of twisted mica-schists (sometimes with large garnets) in which, 

 however, the black pyritous bands, now also converted into mica-schists, can be 

 easily recognised. These stages in metaraorphism were illustrated by a series of 

 specimens collected along a horizontal distance of six miles in the Gula Valle3% 



The author pointed out the close resemblance of these Norwegian rocks to 

 those that constitute the main mass of the central and southern Highlands of 

 Scotland. He showed that they could be easily distinguished from the Archtean 

 series in both countries ; that they were essentially of sedimentary origin but with 

 important volcanic intercalations; that the fossil evidence from Norway proved 

 them in that country to be of Silurian age ; and that a similar conclusion as to the 

 age of those in Scotland might be drawn from the stratigraphy of the Highlands. 



The Bergen area has been excellently mapped and described by Dr. lieusch, 

 who first discovered fossils there in a tine mica-schist or phyllite. The author 

 succeeded in obtaining fossils from all the localities mentioned by the Norwegian 

 geologist, and verified his observations as to the intercalation of the fossiliferous 

 rocks among bands of metamorphosed sedimentary strata and of gneisses and more 

 or less deformed igneous masses. The rocks, approximately vertical, are arranged 

 in parallel strips having a general north-easterly strike. Their relations to each 

 other were not very clearly displayed in the sections which the author examined. 

 They appeared, however, to be thrust over each other, wedges of possibly Archsean 

 rocks being thereby intercalated between obviously clastic beds. The main point 

 of interest, however, was perfectly clear — viz., that a rock containing Upper Silurian 

 fossils had become a finely puckered or frilled mica-schist or phyllite. The 

 regional metamoi-phism in the Bergen district was thus proved to have taken place 

 after some epoch in the Upper Silurian period — a conclusion in harmony with 

 recent observations of the Geological Survey in the west of Ireland. 



2. Bijnamic Metamoiyhism of Shiddaw Slates. 

 Bj J. E. Marb, M.A., Sec.G.S. 



In the belt of Skiddaw slates running along the west side of the Crossfell Escarp- 

 ment from Melmerby to Roman Fell, several large masses of quartz veins occur, 

 trending generally in a W.N.W.-E.S.E. direction. The best exposure is on the 

 east side of Browuber. Here the large quartz veins were evidently intruded along 

 bedding planes before the main folding took place. They are now extremely con- 

 torted, and the slates have undergone alteration, being converted into a rock, 

 composed largely of mica and secondary quartz, and exhibiting ' i\.usweichungs- 

 clivage ' — in fact, a mica-schist. 



Many cubes of pyrites are scattered through the rock, and have been slightly 

 deformed, with formation of a fibrous mineral around the crystals. 



The slates are not greatly altered, except in belts where the quartz veins come, 

 and as these were (as above stated) formed before the principal folding, it would 

 appear that the alteration of the slates is due to the ditferential movement produced 

 between the hard quartz and soft slate, as shown by the universal slickensiding of 

 the divisional planes. 



3. On the Lower Silurian Fehites of the Soufh-East of Ireland.^ 

 Bu Dr. P. H. Hatch. 



In this paper are coramimicated twelve analyses, by Mr. J. Hort Player, of 

 felsites from the Lower Silurian (Bala) beds of the counties Wicklow and Water- 

 ford. The main point brought out by these analyses is the almost entire absence 



> Published in cxfenso in the Geol. Man. for December 1880, pp. 545-549. 



