The Geology of the Cader Idris Range (Merioneth)

Publisher Website
Google Scholar
Abstract
I. Introduction. The mountain-range of Cader Idris is formed by a great escarpment of Ordovician volcanic rocks which looks northwards across the Mawddach estuary towards the extensive area of Lower Cambrian rocks comprised in the Harlech Dome. The range has a general east-north-east to west-south-west trend, but the central portion runs almost due east and west. Along the range from east to west are the following summits, all exceeding 2000 feet in altitude:—Geu Graig, Mynydd Moel, Pen y Gader (2927 feet, the highest point), Cyfrwy (or The Saddle), Tyrau Mawr, and Craig y Llyn. Situate a little south of the main escarpment, but connected with it by cols, are the heights of Mynydd Pencoed and Craig Cau. The range is bounded on the south by the Talyllyn Valley, and on the north by the valley running from Dolgelley past Llyn Grwernan. Both these valleys trend nearly north-east to south-west, and follow the lines of repeating faults; along them run the chief and almost the only roads within the district mapped. North of the Llyn Grwernan Valley a smaller hill-range, or rather a series of ranges, intersected by the Gwynant Valley, intervenes between Cader Idris and the Mawddach estuary. The greater part of the area included in the map (PL XXXVII) lies above the 1000-foot contour, much of it indeed above the 2000-foot line, so that most of the ground is uncultivated and given over entirely as pasturage for sheep. Cultivated ground is restricted to small patches along the Llyn Gwernan

This publication has 0 references indexed in Scilit: