Hydrothermal Deposits - Metals and Society: An Introduction to Economic Geology - page 105

Table 4.4 Summary of characteristics of main types of uranium deposits
Age Proportion a (%) Geological features Grade Examples

Unconformity-
related deposits

Proterozoic 0.4-24% 30 Near major unconformities between

sandstones at the base of sedimentary
basins and metamorphic basement
rocks

Athabasca Basin, Canada; McArthur
Basin, Australia.

Sandstone deposits Paleozoic-

Cenozoic

0.05-0.4% 15 Sandstones in a continental fluvial or

marginal marine sedimentary
environment interbedded with shale
or mudstone

Wyoming Basin and Colorado Plateau,
USA; Central Europe, Kazakstan

Quartz-pebble
conglomerate
deposits

Paleoproterozoic 0.01-0.15% 10 Stratiform and stratabound paleoplacer

deposits

Witwatersrand, South Africa; Elliot
Lake, Canada

Iron-oxide copper
gold deposits

Proterozoic 0.04-0.08 40 Hematite-rich granite breccia Olympic Dam, Australia

Intrusion associated
deposits

Proterozoic 0.03 5 Veins in leucogranite Rossing, Namibia

Volcanic deposits Precambrian to

Cenozoic

0.02-0.2% 1 Veins and breccias in felsic to

intermediate volcanic rocks

Streltsovskoye, Russia; Dornod,
Mongolia; McDermitt, Nevada.

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Surficial deposits
(calcretes)

Tertirary to
recent

0.15 5 Near-surface uranium concentrations

in sediments or soils

Yeelirrie, Australia

a Approximate percentage of global uranium resources