This book applies step by step the classical principles and methodology of determining paleoenvironment of deposits or sedimentary outcrops. The unique approach and style of presentation makes the principles easy to apply. It observes sedimentary structures, textural features and morphometric characters of seven outcrops exposure of a sandstone Formation (Lokoja Sandstone, Bida basin, Nigeria), and reconstruct them to arrive at environment of deposition. Among the principles applied in this book includes Walther's law of facies succession (applied to reconstruct the sedimentary facies), the statistical principles after Folk and Ward, 1957, Friedman, 1967, Miola and Weiser, 1968, Sahu, 1968, Visher, 1969 and Salley, 1985, and the morphometric principles after Sneed and Folk, 1958, Lutig, 1962, Dobklins and Folk, 1970, and Stratten, 1973. Besides, trace fossils characteristic within the Formation were identified and integrated with other principles to arrive at the environment of deposition.