Frabric analysis of rock glacier debris rock mantles, La Sal Mountains, Utah

TitleFrabric analysis of rock glacier debris rock mantles, La Sal Mountains, Utah
Publication TypeJournal Article
Year of Publication1994
AuthorsNicholas JW
JournalPermafrost and Periglacial Processes
Volume5
Pagination53-66
KeywordsRock Glacier, Utah
Abstract

Macrofabrics of rock glacier debris mantles display significant variation even among similar microtopographic features. Fabrics of longitudinal ridges of La Sal rock glaciers are equally divided between cluster and girdle distributions. In some cases, fabric patterns resemble those of lahars, implying that the flow mechanics of rock glaciers bears some similarity to that of large-scale debris flows. Shear zones are found at the margins of many longitudinal ridges, and in at least one case these zones separate the rock glacier from a pair of bounding ridges that resemble debris-flow levees. Other sites display fabric patterns that indicate that the dominant processes are dry creep of the open-matrix debris mantle. Weak fabrics are found at sites where rockfall inputs occur on a low-angle surface, or where a debris mantle is undergoing passive transport by a moving core.