Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/323

This page has been proofread, but needs to be validated.

the granite, and are found in the bed of the river, do not run to any extent through the mass of strata. It is therefore probable that they are not veins, but simply irregularities, of the granite.

The junctions of granite in the Tilt are not therefore the transit of independent granite veins like those of Portsoy or Rona, but the interrupted portions of a continued line of junction between a great surface of stratified rocks, and an equally extensive but irregular surface of granite.

Wherever this junction is found, a complicated disturbance of the whole rocks at the point of junction is seen, and small veins of granite are observed penetrating the stratified rocks.

In these places of junction the granite becomes so intimately mixed with the limestone as to alter its character, and wherever the granite is in contact both with schist and limestone, a similar mixture and transition between those two substances takes place.

In all other cases the schistose and calcareous rocks preserve both their regular disposition and their ordinary chemical characters.