Surficial geologic map of the Circle mining district, Alaska
Description
Surficial geologic map of the Circle mining district, Alaska, Report of Investigation 95-2C, presents results from a geologic investigation of surficial deposits in parts of the Circle B-1, B-2, B-3, B-4, C-2, C-3, and C-4 quadrangles. The surficial deposits of the Circle mining district have long been sources of placer gold and even alluvial diamonds. Throughout most of the map area, the bedrock surface is blanketed by periglacial slope deposits consisting of silty rubble with angular and subangular clasts of local bedrock. This unconsolidated unsorted material was produced by intense frost shattering of bedrock and was spread downslope by mass movement processes. These processes are still active in the area today. In valley bottoms, terrace and floodplain alluvium consist of coarse, angular to subangular gravels. In upland valleys, the locally auriferous are commonly mixed with slope debris. Radiocarbon dating of organic sediments ranges in age from mid-Wisconsonian to Holocene. Although frost is discontinuous, sentiments in the valley are generally frozen and locally contain bones of large extinct vertebrae. Although landforms have been extensively modified by erosion, frost action, and mass movement, recognizable glacially modified valleys, silty gravel, and till provide evidence of at least one former glaciation. Glaciation of North Harrison Creek probably had a significant effect on the distribution of nuggets there. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/2516.
Resources
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Description |
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geologic map |
https://doi.org/10.14509/2516 |
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https://doi.org/10.14509/2516 |
Tags
- paleozoic
- mastodon creek
- switch creek
- tailings
- holdem creek
- circle hot springs
- butte creek
- fluvial deposits
- gold dust creek
- floodplain
- ketchem creek
- geochronology
- surficial geologic map
- geomorphology
- ketchem dome
- berry camp
- porcupine dome
- two-bit creek
- deadwood creek
- quaternary
- birch creek
- buckley bar creek
- greenhorn creek
- pinnell trail
- gravel
- willow creek
- fish creek
- colluvium
- tertiary
- peat
- yankee creek
- fossils
- geology
- colluvial deposits
- undifferentiated bedrock
- glacial deposits
- hot springs creek
- surficial
- terrace alluvium
- dome creek
- geologic map
- cripple creek
- photogeologic lineaments
- porcupine creek
- crooked creek
- permafrost and periglacial
- half dollar creek
- non-metals
- unconsolidated deposits
- gelifluction
- eagle creek
- bedrock creek
- eolian
- eagle summit
- floodplain alluvium
- independence creek
- portage creek
- sawpit creek
- alluvial fan
- bear creek
- deadwood
- easley creek
- mastodon dome glaciation
- slate creek
- surficial geology
- mastodon dome
- bottom dollar creek
- mastodon
- miller creek
- alluvial deposits
- traverse creek
- circle mining district
- boulder creek
- bonanza creek
- alluvium
- glacial
- ptarmigan creek
- bates creek
- permafrost
- mammoth creek