Surficial deposits

Sur cia.1 Deposits. Uraniferous surficial deposits maybe broadly defined as uraniferous sediments, usually of Tertiary to recent age which have not been subjected to deep burial and may or may not have been calcified to some degree. The uranium deposits associated with calcrete, which occur in Australia, Namibia, and Somaha in semiarid areas where water movement is chiefly subterranean, are included in this type. Additional environments for uranium deposition include peat and bog, karst caverns, as well as pedogenic and stmctural fills (15). 

Huntley, D., Mills, A., Paulen, R.C. 2008. Surficial deposits, landforms, glacial history, and reconnaissance drift sampling in the Trout Lake map area, Northwest Territories Geological Survey of Canada, Current Research 2008-14, 14 p. 

Surficial deposits at XY are dominated by tills and colluvium, which have been locally reworked by alluvial and glacio-fluvial processes (Figs. 1 2a). On the transect reported herein, the depth of overburden varies from negligible on mountain sides to at least 5 m thick in central parts of the till plain in central valley areas (unknown maximum thickness). In the section of the traverse the XY ore zone is c. 10 m thick, and occurs below c. 3 m of colluvial overburden (Fig. 2). Pedogenesis is generally restricted to minor to moderate horizonation that has produced predominantly brunisols (Canadian Soil Classification System, Agri-Canada 1998). 

The area portrayed in Fig. IB is underlain by bedrock of Late Cretaceous age, which in turn is overlain by glacial till and surficial deposits. The bedrock geology of the area was summarized by Green (1972). Two bedrock units subcrop in the area the Bearpaw Formation and below this, the Belly River Formation. The strata dip gently to the southwest at 1 m/km. Lithologic descriptions for the two units are as follows ... 

Sedimentary rocks underlying the study site range in age from Upper Cretaceous to late Eocene. A thin surficial deposit of unconsolidated, post-Eocene residuum overlies the bedrock. The geologic units pertinent to the study are, in ascending order, the Lisbon Formation, the Clinchfield Sand, the Ocala Limestone, and the undifferentiated residuum (Figure 3). 

Elemental distribution patterns in regoliths partly result from long-term geochemical changes occurring in surficial deposits and soil profiles. Accordingly, these patterns were used to calculate weathering rates (Olsson and Melkerud,... 

Jones LM, Faure G (1978) A study of strontium isotopes in lakes and surficial deposits of the ice-free valleys, southern Victoria Land, Antarctica. Chem Geol 22 107-120 Jones LM, Faure G (1968) Origin of the salts in Taylor Vrilley. Antarctic JUS 3(5) 177-178... 

Surficial deposits undivided, chiefly wadi alluvium and fluvial terraces... 

A new architecture of surficial deposits and topsoil is recommended, based on the layout of the original structure of the surficial geology of the slopes in which the mine is located. 

Surficial deposits comprise about 4% of world uranium resources, and such deposits represent 5% of Australia s total reserves and resources of uranium. They formed where uranium-rich granites were deeply weathered in a semi-arid to arid climate. The Yeelirrie deposit in Western Australia is by far the world s largest surficial deposit. 

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