The nature of geological maps: the Ten Mile map of the UK and the 1: 2 500 000 map of the USA

Abstract

This chapter will use portions of two real examples of geological maps, one of the UK and one of the USA, to introduce some aspects of map interpretation. It provides a preliminary glimpse of the kinds of interpretations that can be made before the various concepts are examined more closely in succeeding chapters. We begin by noting some of the cartographic matters; first, the scale. Despite its time-honoured name, the Ten Mile UK map (Plate 1) is actually at a scale slightly larger than ten miles to the inch, at 1: 625 000. There is a north sheet and a south sheet to cover the whole of Great Britain. The US map (Plate 2) is at 1: 2 500 000 and comes in three sheets: the east and west halves of the map and a separate sheet showing the legend.