By Peter Kennett.
The locations of 11 sites are shown on a specially redrawn geological map and identified by grid reference, photographs and sketches. Geological features range from gritstone tors on Burbage Moor at Ringinglow to former sandstone quarries on Brincliffe Edge. With perseverance, evidence of former marine conditions may be found in the shales of the river banks. The age of the rocks ranges from the Chatsworth Grit (of "Millstone Grit" age) to the Greenmoor Rock of Lower Coal Measures age. Because of the general easterly dip of the strata, the oldest beds occur at the head of the valley and the youngest lower down its course.