 | Robert Bradford Marshall - 1912 - 826 Seiten
...operators to wash the gravel at a profit. Throughout the intermediate portion of the river the bedrock lies at unknown depths beneath a mantle of glacial...throughout this middle portion of the Chisna Valley has ul any postglacial time been operative down to bedrock, so that, even could the latter be reached,... | |
 | 1912 - 526 Seiten
...operators to wash the gravel at a profit. Throughout the intermediate portion of the river the bedrock lies at unknown depths beneath a mantle of glacial...throughout this middle portion of the Chisna Valley has at niiy postglacial time been operative dowa to bedrock, BO that, even could the latter be reached, it... | |
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In both of these regions bedrock had been reached on some of the claims at varying and usually not excessive depths, and wherever found It carried sufficient gold to enable the operators to wash the gravel at a profit. Throughout the intermediate portion... 