Address by Professor B. N. Peach. 461 



In 1911 Dr. Campbell announced in the Geological Magazine that 

 fossils had "been found in the Highland border series north of Stonehaven, 

 and, during this year. Dr. Jehu made a similar discovery in rocks 

 belonging to this series near Aberfoyle. Papers on these subjects will 

 be communicated to this section. For my present purpose it will be 

 sufficient to indicate the nature of the fossils and the lithological 

 characters of the rocks containing them. 



The Highland border series north of Stonehaven and near Aberfoyle 

 includes sheared igneous rocks, both lavaform and intrusive, with black 

 shales, cherts, and jaspers. JSTorth of Stonehaven the fossils occur in 

 thin, dark, flinty pyritous shale, while at Aberfoyle they have been 

 found in shaly films at the edge of the chert bands. Several years 

 ago Eadiolaria were detected in the cherts between Aberfoyle and 

 Loch Lomond. From time to time these Highland border rocks have 

 been carefully searched for fossils, but until recently with little success, 

 owing to the intense movement to which they have been subjected, 

 resulting in marked flaser structure in all except the most resistant 

 bands. 



The fossils consist chiefly of horny, hingeless Brachiopods, Phyllocarid 

 Crustacea, worm tubes, and the jaws and chetse of Annelids. The genera 

 of Brachiopods comprise Lingulella, Obolus, Oholella, Acrotreta, and 

 Linarssonia. The association of these Brachiopods with Phyllocarid 

 Crustaceans resembling Rymenocaris and Lingulocaris is suggestive of 

 an Upper" Cambrian horizon — an inference which is supported by the 

 absence of Grraptolites. 



In the published Geological Survey maps these Highland border rocks 

 are queried as of Lower Silurian age. This correlation was based 

 partly on their resemblance to the Arenig volcanic rocks and Radiolarian 

 cherts of the Southern Uplands, and partly because, as shown by 

 Mr. Barrow, they are overlain by an unconformable group of sediments, 

 termed by him the Margie Series. The cherts, the green schists, and 

 the Margie Series have shared in a common system of folding, and are 

 unconformably surmounted by Downtonian strata near Stonehaven. 

 Though the original correlation may not be strictly correct, it is probable, 

 in my opinion, that representatives of both the Arenig and Upper 

 Cambrian formations may occur in the Highland border series, and, 

 further, that Upper Cambrian strata may yet be found in the Girvan 

 area, as originally suggested by Professor Lapworth in correspondence 

 with Dr. Horne. 



The Cambrian Fauna of North America. 



[We are unable, from want of space, to give the particulars here 

 related by Dr. Peach, and therefore quote only the conclusions at 

 which he has arrived.] 



The palaeontological evidence adduced regarding the relation of the 

 Cambrian fauna of the North- West Highlands to that of North America 

 leads to the following conclusions : — 



1. The Lower Cambrian fauna of the North- West Highlands, dis- 

 tinguished by the genus Olenellus and its associates, is almost identical 

 in character with that of the Georgian terrane of the western life- 

 province of North America, and essentially different from the Lower 

 Cambrian fauna of the rest of Europe. 



2. No forms characteristic of the Middle Cambrian division, either 

 of Europe or North America, have as yet been found in the North-West 

 Highlands ; but this division may be represented by the unfossiliferous 

 dolomites and limestones of the Ghrudhaidh, Eilean Dubh, and the 

 lower Sail Mhor groups. 



3. The fossiliferous bands of the Sail Mhor group may be the 

 equivalents of the lower part of the Upper Cambrian formation. 



4. The Balnakeil and Croisaphuill groups of the Durness dolomites 



