English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A reconnaissance of the Bear Valley district was undertaken to provide a geologic interpretation of placer deposits drilled by the U. S. Bureau of Mines. The placer minerals are monazite and a group of uranium bearing rare earth columbates and tantalates here referred to loosely as radioactive blacks. The monazite is an accessory mineral in the granitic country rock; the radioactive blacks oocur in pegmatite dikes. The supply of these minerals to the placers was controlled by the geography of their occurrence in the parent rocks and by the distribution of alpine glacicrs during two late Pleistocene glacial stages. By reason of a favorable combination of thcse factors, the richest placer deposits of the district are in Big Meadows a valley fill formed as a result of the blocking of Bear Creek by a glacicr from a tributary valley during the Illinoian (?) stage. The Big Meadow fill consists of intertonguing depositional units formed by Bear Creek and its tributaries, including both normal alluvium and glacial outwash, and ranging froin rich to barren. The richest phase that has been blocked out by drilling was derived from the drainage basin of Casner Creeks an east tributary of Bear Creek. The geologicmore » relations suggest that a neighboring stream, Howard Creek, should have supplied equally rich material, but the part of the valley fill formed by Howard Creek has not been tested. The Howard Creek deposits and shallow alluvium in the upper valleys of Casner and Howard Creeks may considerably increase the reserves of the district. (auth)« less

Reconnaissance geology of placer deposits containing radioactive minerals in the Bear Valley district, Valley County, Idaho