Volcanic tuff thin section exhibiting welded angular clasts of varying size. A degree of orientation can be identified as a result of the fallout of volcanic ejecta. Volcanic tuff is formed from phreatomagmatic eruptions, where volcanic material such as ash and pyroclastic bombs are ejected from the volcano during eruptions. Tuff is essentially derived from volcanic ash which has settled and over time through various geological processes, the ash consolidates into a solid rock which geologists know as tuff. This material comes from the Borrowdale valley in Cumbria, an area rich in volcanic history, the valley itself is actually named after the Borrowdale Volcanic Group, which is comprised of a series of various volcanic rocks which formed during the Ordovician period. Each section is made to 30 microns thickness and the glass is 46 x 27 mm in size with a cover slip. Supplied in a protective card sleeve with a label, ideal for microscopy.