may be had by walking a short distance from the summit in any direction. Much of the Lake District, the hills of south-west Scotland, the Eden Valley and the Pennine Hills may be seen on a clear day. Another small cairn lies part way down the western slope on the path to Clough Head, marking the minor top of Little Dodd. Geology The rocks of Great Dodd are all part of the Borrowdale Volcanic Group, formed on the margin of an ancient continent during a period of intense volcanic activity, roughly 450 million years ago in the Ordovician Period. Within that Group, the bulk of the rocks forming the fell belong to the Birker Fell Andesite Formation. These rocks are among the earliest of the volcanic rocks of the Borrowdale Volcanic Group, and are part of a thick succession of andesite sheets which now outcrop in a wide band around the western and northern sides of the Lake District, and probably underlie much of the other volcanic rocks. These sheets were formed by successive eruptions of mobile andesitic lava from shallow-sided volcanoes. The composition of the erupting magma varied from time to time, with domes of more viscous dacite occurring in a number of places. Calfhow Pike, Randerside and High Brow are all shown as dacite on the geological map. Individual lava flows may be separated by beds of volcaniclastic sandstone, sedimentary deposits formed from the erosion of the volcanic rocks and deposited by streams, floods and possibly wind. The geological map shows a number of areas of volcaniclastic sandstone on the western slopes of Great Dodd, above Beckthorns and Fornside. After the eruptions of the Birker Fell Formation, the composition of the erupting magma changed from largely andesitic to predominantly dacitic, and as a result the nature of the volcanism became more explosive. A number of caldera volcanoes were formed. In the area to the north of Sticks Pass the Birker Fell andesites are overlain by the Lincomb Tarns Tuff Formation. This formation is one of the most widespread of the volcanic rocks of the Lake District; it seems that the whole district was buried beneath at least 150 m of densely welded ignimbrite, a rock formed from a pyroclastic flow of very hot gas and rock. This formation must represent a series of eruptions of truly exceptional magnitude, accompanying the formation of a volcanic caldera probably in the