graphic log

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graphic log An outline description of a particular sequence of rocks, made in the field and set out in columnar form. It is usual to sketch in each succeeding rock unit with its appropriate lithologic symbol, and draw thicknesses of units to scale. Subsequent columns contain data concerning: particle size (shaded in according to a horizontal scale); sedimentary structures; fossils; colour; palaeocurrent directions (see PALAEOCURRENT ANALYSIS); weathering; sorting; and any other salient features gathered under the general heading of ‘remarks’. See also LITHOLOGIC SYMBOL.