The use of duricrusts and topographic relationships in geomorphological correlation : conclusions based in Australian experience
Australia ; Duricrust ; Ferricrust ; Geomorphology ; Inverted relief ; Laterite ; Palaeoclimate ; Silicrete ; South Australia ; Stratigraphic correlation ; Surface deposits
Duricrusted surfaces provide morphostratigraphic markers which are useful in preliminary extrapolation and correlation at the local and regional scales. Particular reference is made to ferruginous and siliceous cappings. Problems broached include
type of landscape development, the relation of surface and duricrusts, and the temporal equivalence of duricrust facies. The roles of duricrusts in relief inversion, surface preservation and climatic interpretation are also mentioned.
This paper aims to explore the process-landform relationships and potential genetic links between duricrust formation and Kalahari valley development, and hence assess the possible influence and implications of groundwater weathering and erosion
upon duricrusts. This is achieved by consideration of relationships between valleys and duricrusts at a variety of scales (ranging between microscale to valley scale) from three mekgacha systems within the Kalahari: the Rooibrak and Letlhakeng valleys
This paper presents the first in-depth investigation of cement relationships within Kalahari silcrete-calcrete intergrade duricrusts at a profile scale, through the detailed analysis of the petrology and geochemistry of duricrusts and bedrock
exposed within the quarries at Kang and Tswaane. The combination of micromorphological and geochemical approaches clearly demonstrates the potential of detailed sampling and analysis for determining the environment and mechanisms of duricrust formation
. It also serves to reinforce the significance of topographic depressions (pans and valleys) upon the formation of calcrete, silcrete and calcrete-silcrete intergrade duricrusts within the Kalahari.
The AA. present examples of inversion of relief: in volcanic areas, associated with duricrusts, silcrete, ferricrete, calcrete, gypcrete. They study the implications of inversion of relief for catenas, hydrology, geochemical landscapes and landscape
Duricrust ; Pedogenesis ; Soil ; Soil properties ; South Africa
A review of information on the occurrence, classification, properties and genesis of soils, pedogenic duricrusts and unconsolidated sediments covering pan floors and margins. A three-fold division based on climate was establisehd. - (AJC)
IN WESTERN AND SOUTHWESTERN FRANCE THERE ARE TWO TYPES OF DURICRUSTS: FERRUGINOUS LATERITE AND SILCRETE. WHILE IN AUSTRALIA THESE DURICRUSTS SEEM TO BE CONTEMPORANEOUS AND CONTIGREOUS, THEY ARE SUPERIMPOSED IN FRANCE. THE EARLIER ONES HAS BEEN
The landforms lie at a low altitude in the south-western part of the Sahara and in the Sahel. Some old lateritic duricrusts are still extent on plateaus, especially on the Tagent in central Mauritania. The Continental terminal deposits are coated
with ferruginous duricrusts. During the Quaternary, some ferruginous duricrusts have again been formed in some areas. The landforms are higher and more rugged in South-West Africa (Namibia). But the old surfaces and the glacis have always calcareous crusts
Many pre-Quaternary terrains persist in the contemporary landscape. Tertiary volcanic plains and plateaux are widespread in the Eastern Uplands and duricrusted (ferruginised, silicified) remnants, some of them folded, are characteristic of many
gypsum dust from these playas contributes to the formation of pedogenic gypsum duricrusts on the coastal gravel plains of the Namib Desert surrounding these playas. This study establishes the nature, extent and distribution of playas in the Central Namib