Shallow Trench
On the ground, most of the lines are formed by a shallow trench with a depth of between 10 cm (3.9 in) and 15 cm (5.9 in). Such trenches were made by removing the reddish-brown iron oxide-coated pebbles that cover the surface of the Nazca desert. When this gravel is removed the light-colored clay earth which is exposed in the bottom of the trench produces lines which contrast sharply in color and tone with the surrounding land surface. This sublayer contains high amounts of lime which, with the morning mist, hardens to form a protective layer that shields the lines from winds, thereby preventing erosion.
© Kieron Nelson 2013 "Vanishing Cultures Photography" All rights reserved
