Stone Nets, Stone Stripes, and Soil Stripes in the Wind River Mountains, Wyoming

Abstract

Stone nets, stone stripes, and soil stripes have formed on high, flat erosion surfaces at altitudes ranging from 11,200 to 13,000 feet in the Wind River Mountains, Wyoming. Although the frost-heave theory of Hogbom is accepted as accounting for the segregation of coarse material at the surface of ground which has undergone alternate freezing and thawing, certain weaknesses in this theory and in other theories for the origin of stone nets cause them to be unsatisfactory as explanations of those structures in the Wind River Mountains. A theory is developed in which alternate contraction and expansion of frozen ground, under a range of subfreezing temperatures, may produce a net of fractures bounding polygonal areas of frozen ground. Ice wedges form in these fractures and enlarge with successive contractions of the frozen ground. On eventually thawing from the top down, the wedges are gradually replaced by coarse fragments from the upper part of the central polygonal area. Most of the stone stripes are consi...