...often graphitic, together with some graphitic slates. This is part of the schist series which has heen described. The bed rock is much jointed, the schists...miners in the sluice boxes. A sample of the concentrate 6 in one of the sluice boxes was examined by Mr. Arthur J. Collier, and yielded the following minerals:...

...character. The slates and schists are everywhere penetrated by small veins, consisting usually of quart/, with some calcite, and frequently carrying pyrite...again contracting so as not to be easily traceable. 92 BKOOKH.] STREAM TIN IN ALASKA. 93 The stream tin is concentrated on the bed rock with other heavy...

...throughout its extent. At a few localities some deeply weathered, dark-green intrusives were found, probably of a diabasic character. The slates and schists...easily traceable. The stream tin is concentrated on the l>ed rock with other heavy minerals, and was found by the miners in the sluice boxes. A sample of the...

...minerals. In some cases, however, a little plagioclase was still unaltered and a suggestion of opbitic structure remained, so that these are probably of...sample of the concentrate, '' in one of the sluice l>oxes was examined by Mr. Arthur J. Collier, and yielded the following minerals: Cassiterite, magnetite,...

...angles to the course of the stream and offer natural riffles for the concentration of heavier material. The slates and schists are everywhere penetrated by...contracting so as not to be easily traceable. The cassiterite occurs as grains and pebbles, from those microscopic in size to those half an inch in diameter,...