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IX. — The Highland Border Rocks of the Aberfoyle District. By Professor 
T. J. Jehu and Dr Robert Campbell. (With Six Plates and Ten Text-figures.) 
(Read June 4, 1917. MS. received September 10, 1917. Issued separately December 4, 1917.) 
CONTENTS. 
PAGE 
I. Introduction . . . . .175 
II. Review of Previous Work .... 175 
III. General Account of the Stratigraphy of the 
Highland Border Rocks . . . 179 
IY. The Rocks of the Lower or Black Shale and 
Chert Series 180 
V. The Rocks of the Upper or Margie Series . 182 
VI. Palaeontology of the Beds . . . .186 
VII. The Age of the Highland Border Rocks . 193 
VIII. Intrusive Rocks older than the Lower Old 
Red Sandstone 194 
I. Introduction. 
The South-Eastern Highlands are made up of metamorphic rocks chiefly of 
sedimentary but partly also of igneous origin, all of which have been included by 
Sir Archibald Geikie under the term “ Dalradian.” These rocks have been divided 
into bands, which can be traced more or less continuously across Scotland from 
north-east to south-west. There is an apparent order of superposition, and in 
Perthshire the groups or bands are arranged in what looks like an ascending order 
from the Highland Boundary Fault northwards. 
The age of the Dalradian sediments is still an unsolved problem, and great 
uncertainty prevails regarding the true original sequence and the tectonics of the 
various rock groups. It is possible and even probable that in the Dalradian Series 
we have rock groups belonging to different geological periods, though all have been 
affected by a common system of folding. 
Along the southern margin of the Dalradian area, immediately adjoining the 
Highland Boundary Fault, a group of rocks can be traced as an interrupted belt 
from Stonehaven to Arran, and this belt reappears in the same geological position, 
but on a more extensive scale, in Ireland. It consists of grits, shales, limestone, 
cherts or jaspers and cherty shales, graphitic shales, and various igneous rocks 
sometimes highly altered. This group of rocks is usually designated “ The Highland 
Border Rocks.” 
II. Review of Previous Work. 
The literature on the Highland rocks is so extensive that it is impossible within 
the limits of this paper to enumerate all the references to the series with which we 
are immediately concerned. It will suffice to state that in the earlier communica- 
TRANS. ROY. SOC. EDIN., VOL. LII, PART I (NO. 9). 2d 
PAGE 
IX. The Hornblende-Schist Complex and Asso- 
ciated Sediments 197 
X. Comparison of the Margie Grits with the 
Leny Grits ...... 200 
XI. Later Intrusions . . . . . .201 
XII. Tectonics 202 
XIII. Summary of Results ..... 208 
XIV. Acknowledgments 209 
XV. Explanation of Plates ..... 210 
