ABSTRACT
Caliche in the arid climate of southern Nevada is being weathered by mechanical breakup and by solution. Mechanical breakup is the dominant process operating on indurated layers such as petrocalcic and laminar horizons. Solution attacks the softer, non-indurated caliche layers. These softer layers may become case-hardened on exposure, after which mechanical breakup is significant.
Mechanical breakup is probably due mostly to freeze and thaw of water at all altitudes in southern Nevada. The resultant product is a caliche rubble layer which is resistant to further weathering and erosion.
