Determining the relationship between rock colour and the type of physical weathering on desert pavements in arid landscapes, Ras Al Khaimah, UAE

Description

Despite opposition to the theory that diurnal heat fluxes within desert rocks cause enough internal stress to form cracks on clasts leading to the break down of the desert material, this study provides further evidence that this is a credible process in physical weathering. The investigation set out to discover if the colour of a clast determines the likelihood that a clast will experience meridional cracking, as opposed to longitudinal, surface parallel and fabric related cracks near Ras-Al-Khaimah, in the United Arab Emirates. The results did not reveal a relationship that was significant in a Chi-squared Test. The results yielded significant evidence that no specific weathering process would occur on a clast due to its colour. However, the results indicated tensile stresses in the clasts’ interior, which contributes to rapid breakdown and to the formation of desert pavement. The majority of the cracks’ orientations lie closer to the east-west bearing than north-south. This information suggests a new theory for meridiornal cracking although local conditions, such as the geographic location of the Musandam Mountains could explain the results in this instance. Rose diagrams present the evidence found in these proximities. This method enables easy visual analysis for both comparison with McFadden et al’s (2005) data and other such sources and also for the different classes in this study.