22 research outputs found
Effects of two alfalfa preparations with different particle sizes on the gastric mucosa in weanlings: alfalfa chaff versus alfalfa pellets
Isotopic Evidence for Reductive Immobilization of Uranium Across a Roll-Front Mineral Deposit
Typology and Geographic Geotectonic Distribution of Uranium Deposits
In the last ten years, twenty new uranium deposits have been discovered. They provide nearly 50% of the known and reasonably assured resources. The most important deposits known in the past by size and ore grade were those found in oligomictic quartz pebble conglomerates, sandstones and, to a lesser extent, hydrothermal veins. The types found more recently, which are greater in quantity than the former ones, are of the vein type (Canada, Australia) as well as of the intrusive type (Rössing, Namibia) and in calcretes (Yeelirrie, Australia) and acid volcanic rocks (Mexico). Several classifications have been worked out in the past (E. W. Heinrich, 1958; M. Roubault, 1958; A. Mancher, 1962). More recently new data have enabled these classifications to be extended on a worldwide basis (Ruzicka, 1971; Ziegler, 1974; Dahlkamp, 1974, 1978) or on a regional basis (McMillon for Canada, 1978; Ingram for Australia, 1974). This classification attempt takes all available useful data into consideration to define different types of uranium deposits in as comprehensive and strict a manner as possible