Clay Mineral Studies of Some Egyptian Desert and Nile Alluvial Soils

Abstract

Summary Egyptian desert soils are generally of coarser texture than Nile alluvium with only slight depositional changes within the same profile. Total N is lower in desert soils than in alluvial soils under similar climatic conditions. On the basis of clay mineral analysis the soils fall into four groups, having (1) kaolinite (Ganah and Kharga), (2) montmorillonite (Beris, Boulaq, Nile alluvium), (3) hydrous mica (Kharga), (4) attapulgite (desert road), as the dominant mineral. The very slight difference in clay mineral composition between the soil and subsoil or parent material indicates that clay minerals in these soils are derived mainly from a pre‐existing sediment. The mechanical analysis and mineralogical study of the heavy mineral fraction showed that the soils of Kharga oasis are either water‐laid sediments (Boulaq and Beris) or wind‐modified (Ganah and Kharga). Whether or not the qualitative similarity of the clay minerals of the soils from mid and southern Kharga with those of the Nile alluvium indicates a genetical relationship cannot be definitely ascertained from this study.

Experimental and statistical study of saturated hydraulic conductivity and relations with other soil properties of a desert soil

“…This study was carried out in the Kharga Oasis in the western desert of Egypt (Figure ). The oasis is a wind‐ablated depression about 18‐km long and 15–30‐km wide carved into Cretaceous–Tertiary marine strata that form the Libyan Plateau (Elgabaly & Khadr, ). The oasis was formed by structural differences and subsequent exposure to wind, and dry and wet seasons.…”

“…The soil of the Kharga Oasis relates primarily to the different parent materials derived from pre‐existing sediments of fluvial origin mixed with windborne material (Elgabaly & Khadr, ). The soil in the depressions is classified as Chromic Haplotorrert or Typic Haplotorrert with moderate capability to produce common cultivated crops, whereas the soil on the depression margins is classified as Typic Torripsamment with very severe limitations for crop cultivation (USDA, ; Gad, ).…”

Authigenic Silicate Minerals – Sepiolite-Palygorskite, Zeolites and Sodium Silicates

“…Transmission electron microscopy (TEM) of dried suspensions has often been used to detect or confirm the presence of palygorskite or sepiolite, based on the typical fibrous morphology of these minerals (Yaalon, 1955;Barshad et al, 1956;Elgabaly, 1962;Elgabaly & Khadr, 1962;Al-Rawi & Sys, 1967;Altaie et al, 1969;Abtahi, 1977;Viani et al, 1983;Gü zel & Wilson, 1985;Heidari et al, 2008). It can therefore also be used to determine relative abundances of these minerals (e.g.…”

Distribution of the Fine-Grained Sediment Component in the Mediterranean

“…Sands are characterized by hornblende and epidote (Sukri, 1950), while clays are dominated by montmorillonite together with considerable amounts of kaolinite (Elgabaly and Khadar, 1962);Hamdi, 1967;Fayed, 1970). Thus, the mineralogy of the turbidites indicates a fluviatile origin from the Nile.…”