very steep and unmarked. A path appears near the top of Middle Dodd, and then leads along the northern ridge to the summit of Red Screes. Geology All the rocks of Red Screes are part of the Borrowdale Volcanic Group, formed on the margin of an ancient continent during a period of intense volcanic activity during the Caradoc epoch of the Ordovician period, roughly 450 million years ago. The lowest (and oldest) rocks, around the base of the fell and on the southern half of the south ridge, belong to the Seathwaite Fell Sandstone Formation. This consists mainly of deposits of bedded volcaniclastic sandstone and siltstone, deposited rapidly in shallow water at a late stage during the volcanic activity. South of Snarker Pike there are more than 800 m of these sediments. Interbedded pyroclastic rocks vary from thin beds of fine tuff to thick units of breccia, and reveal some ongoing volcanic activity during the period of deposition. Overlying those deposits are rocks of the Lincomb Tarns Tuff Formation, found on the eastern and western sides of the fell and the top of the southern ridge. These rocks are predominantly dacitic lapilli-tuff, interpreted as welded ignimbrite. Interbeds of thin tuff and of volcaniclastic sandstone occur. This formation is the most widespread in the volcanic rocks of the Lake District; it seems that the whole district was buried beneath at least 150 m (and in places up to 800 m) of densely welded ignimbrite. It must have been a series of eruptions of truly exceptional magnitude, as viscous and highly gaseous silica-rich magma exploded on eruption. Intrusions of the Borrowdale Sill Suite are found on Red Screes within both the rock formations just described. These andesite sills were intruded during the volcanic activity of the Caradoc Epoch, and may represent one of the last episodes when magma rose to or near the surface that is preserved in the volcanic rocks of the Lake District. Overlying the Lincomb Tarns Formation are rocks of the Esk Pike Sandstone Formation. On Red Screes these are found high on the northern ridge. In this area the formation consists of alternating thick pebbly sandstone beds and thin beds of finer-grained sandstone and mudstone. These represent a return to water-borne sedimentation in an environment of rivers and lakes. The highest and youngest rocks of the Borrowdale volcanic sequence found on Red Screes belong to the Middle Dodd