General Information
Abstract: Preliminary surficial geological investigations of the southern Carmacks-Minto copper belt (NTS 115I/7) include material thicknesses, distribution and observations of thermal conditions. The Quaternary setting is discussed in relationship to material genesis and geomorphological processes operating on the landscape. Surficial material distribution is controlled by ice flow direction, prevailing wind direction and aspect-related differences in gravity and thermal-driven surficial processes.
Valley bottoms and north-facing slopes have moderate to thick surficial cover that include far travelled sediments such as till, loess and glaciolacustrine sand. Drainage can be poor in these
landscapes and permafrost is present in many areas. Valley bottoms contain thick Quaternary fill and are unsuitable for traditional soil surveys. North-facing slopes may provide good geochemical results if sampled carefully for first-order bedrock derivatives. Upland and south-facing slopes have thin to moderate surficial cover and can provide good conditions for traditional C-horizon soil sampling surveys. Windblown sand, silt and volcanic ash are deposited thickly, but unevenly, across the landscape. These sediments dilute surficial geochemical samples and are often incorporated into other materials through cryoturbation, and fluvial and gravitational reworking. Geochemical dilution by eolian materials is more significant near the Yukon River floodplain and in the central Carmacks-Minto copper belt.
Future surficial geochemical surveys should use a variety of methods suited to landscape characteristics and well-described surficial material characterizations. Applying surficial landscape models to existing soils data may also improve their utility for exploration. High quality surficial mapping is a critical part of surficial geochemical surveys and new products in this area will benefit from the use of airborne lidar.
Valley bottoms and north-facing slopes have moderate to thick surficial cover that include far travelled sediments such as till, loess and glaciolacustrine sand. Drainage can be poor in these
landscapes and permafrost is present in many areas. Valley bottoms contain thick Quaternary fill and are unsuitable for traditional soil surveys. North-facing slopes may provide good geochemical results if sampled carefully for first-order bedrock derivatives. Upland and south-facing slopes have thin to moderate surficial cover and can provide good conditions for traditional C-horizon soil sampling surveys. Windblown sand, silt and volcanic ash are deposited thickly, but unevenly, across the landscape. These sediments dilute surficial geochemical samples and are often incorporated into other materials through cryoturbation, and fluvial and gravitational reworking. Geochemical dilution by eolian materials is more significant near the Yukon River floodplain and in the central Carmacks-Minto copper belt.
Future surficial geochemical surveys should use a variety of methods suited to landscape characteristics and well-described surficial material characterizations. Applying surficial landscape models to existing soils data may also improve their utility for exploration. High quality surficial mapping is a critical part of surficial geochemical surveys and new products in this area will benefit from the use of airborne lidar.
Authors: Kennedy, K., Sack, P.J. and Clarke, H.
NTS Mapsheet(s): 115I06, 115I07, 115I10, 115I11, 115I12, 115I13, 115I14
Citation: Kennedy, K., Sack, P.J. and Clarke, H., 2022. Surficial geochemical setting of the southern Carmacks-Minto copper belt. In: Yukon Exploration and Geology 2021, K.E. MacFarlane (ed.), Yukon Geological Survey, p. 107–124.
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Location Map
NTS Mapsheet(s): 115I06, 115I07, 115I10, 115I11, 115I12, 115I13, 115I14
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Related Publications
| Number | Relationship | Authors | Title |
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| YEG2021 | Contained By | Yukon Geological Survey | Yukon Exploration and Geology 2021 |
