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Superficial deposits
Published in A.C. McLean, C. D. Gribble, Geology for Civil Engineers, 2017
In arid regions where soils are enriched in lime, a layer of caliche may be formed. Such a deposit is formed on a peneplain in a climate that leads to sharply defined alternations of saturation and desiccation. Caliche is a ‘hard cap’ deposit produced by upward capillary migration of ground waters during the arid period. Depending upon the composition of the underlying rock, and therefore the composition of these migrating solutions, precipitates of carbonate (calerete), siliceous (silcrete) or ferruginous (ferricrete) materials may be deposited. The position of deposition of different chemical layers depends upon the solubility of the constituents of the migrating solutions, the most soluble salts being deposited nearest the surface (although rainwater action may produce a reversed sequence just below the surface).
Utilising geochemical data for the identification and characterisation of mineral exploration sample media within cover sequence materials
Published in Australian Journal of Earth Sciences, 2019
C. J. Tiddy, S. M. Hill, D. Giles, B. G. van der Hoek, V. J. Normington, R. R. Anand, E. Baudet, K. Custance, R. Hill, A. Johnson, S. McLennan, C. Mitchell, D. Zivak, W. Salama, K. Stoate, K. Wolff
The assignment of ‘ferricrete’ and ‘ferruginous sediment’ is also based on the rock type originally assigned by the author of the source dataset. The term ferricrete has been used for 96 samples from the Kangaroo Island dataset (Stoate, 2016) and one sample from Yorke Peninsula (Dietman, unpubl). The authors use ferricrete as a collective term for iron-rich material that has no distinctive sedimentary features. The term ‘ferruginous sediment’ is more widely used (see Figure 2) and applies to iron-rich material that has an obvious siliciclastic component (e.g. contain quartz and feldspar).
Compositional characteristics and genetic affinity of the ferricrete deposit in Adi Kokeb district, northwestern Tigray, Ethiopia
Published in Applied Earth Science, 2019
Yeman Gebru, Anthony Azubuike Elueze, Kassa Amare, Franck Wilfried Nguimatsia Dongmo
The ferricrete is massive and features densely packed pisoliths or nodules of iron oxide (Figure 3(B)). The iron-rich cement strongly binds pisolites (Figure 3(B)). The ferricrete is reddish to dark brown (Figure 3(B)). In places, iron oxide occurs as irregular thin bands within the ferricrete (Figure 3(E)).