The Highland Boundary Fault : Reverse or Wrench Fault?
DETAILED work which I have done in the Loch Lomond area suggests a definite answer to the above problem which is of some importance since it concerns one of the major geological features of the British Isles. The direction in which the principal stress acted in the production of the fault can be approximately determined from the pattern of structures in the Lower Old Red Sandstone conglomerates, and this supports the contention put forward in stratigraphical accounts (summarized by J. G. C. Anderson1) that the Highland Boundary Fault is a reverse fault of Caledonian age and not a Proto-Armorican wrench fault as envisaged by E. M. Anderson2.
The Highland Boundary Fault in East Tyrone
Abstract Correlation of the metamorphic inlier of Co. Tyrone with the Connemara Schists, together with a reinterpretation of the"Tyrone Igneous Series" erected by J. J. Hartley, lends support to recent suggestions that the Highland Boundary Fault originated as a normal fault with downthrow to the north. The palaeogeographical implications of this are briefly discussed.
XXV.—Metamorphism in Relation to Structure in the Scottish Highlands
The main object of tho present paper is the consideration of the structure of the Central and S.W. Highlands as shown up by the metamorphic condition of the beds. This metamorphic condition has boon studied over the length and breadth of the country, mapped and deduced from very many outcrops in all districts. Sometimes it was possible to superpose the the details respecting the metamorphism upon the 1-inch maps of the Geological Survey, but in many other cases the areas were mapped upon the 6-inch scale. Naturally this work has taken a long time, for it has necessitated the collection of many thousands of specimens, and nearly 3000 rocks have been sliced and examined, since it is not always possible to define the limits of a metamorphic zone with precision by field work alone, and many rock types were encountered that rendered a more careful study advisable than was possible from the mere examination of a hand specimen.