Unnamed (near Mallard Bay)

Location: Alaska, United States (54.771, -132.009 approx.)

Commodities: gold; copper; rare earth elements; uranium; zinc

Deposit model: U-REE-bearing dikes · unclassified

Geology

Syenite is the country rock near the prospects, but most of the radioactive occurrences are in altered andesite dikes that cut the syenite. The andesite has been altered largely to masses of chlorite and clay minerals, but it contains minor relicts of plagioclase and pyroxene. It is strongly fractured· and cut by numerous veinlets that in places form reticulating networks. Two types of veinlets are discernible under the microscope. The oldest veinlets are rich in quartz and hematite and contain subordinate amounts of radioactive minerals. These veinlets are cut by calcite veinlets that lack radioactive minerals. The maximum anomalous radioactivity detected was about 10 times the background. Monazite was questionably identified from these prospects, and it probably is their chief radioactive mineral. (MacKevett (1963))

Record imported from USGS USMIN ver. 4.0 (June 2019). Developments after that date appear on facility records, not here; see the methodology.