| Titre | ACE mineral property, B.C. - Soil and till geochemistry (NTS 093A014E) |
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| Auteur | Lett, R E; Paulen, R C |
| Source | British Columbia Geological Survey Geological Fieldwork Paper 2020-01, 2020 p. 145-165 |
| Liens | Online - En ligne
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| Image |  |
| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200534 |
| Éditeur | Geological Survey of British Columbia |
| Document | publication en série |
| Lang. | anglais |
| Media | papier |
| Formats | pdf |
| Province | Colombie-Britannique |
| SNRC | 93A |
| Lat/Long OENS | -122.0000 -120.0000 53.0000 52.0000 |
| Sujets | levés géochimiques; géochimie du sol; levés pédologiques; géochimie du till; sulfures; gîtes sulfureux; filons de quartz; exploration de dépôts glaciaires; géochimie; Sciences et technologie |
| Illustrations | cartes de localisation; tableaux; graphiques |
| Diffusé | 2021 01 09 |
| Résumé | (disponible en anglais seulement)
A multi-media surficial geochemical survey was carried out by the British Columbia Geological Survey in 2000 to document the geochemical expression of massive
sulphide and gold-quartz vein mineralization at the Ace mineral property, near Likely. Much of the bedrock on the property is concealed by lodgement (basal) till, which was deposited by a southeast to northwest ice advance, ablation till, and
colluvium. Soil samples from the B-horizon soil and transitional B-C horizon, and lodgement till were collected from 85 sites and the <0.063 mm (-230 mesh fraction) was analyzed for more than 50 minor and trace elements and major oxides by three
methods: modified aqua regia dissolution-inductively coupled plasma mass spectrometry; instrumental neutron activation; and lithium metaborate fusion-inductively coupled plasma emission spectroscopy. Samples were also analyzed for carbon, sulphur,
and loss on ignition. Five size fractions ranging from 1-2 mm to 0.125-0.063 mm of selected till and soil samples were analyzed for 35 trace elements by modified aqua regia dissolution followed by ICP-MS. The commodity and pathfinder metals Au, As,
Bi, Co, Cu, Pb, Se, and Zn are present in higher concentrations in the <0.063 mm fraction of the basal till than in the B-horizon soil, likely because the metal content in the silt- and clay-sized fraction of till more closely reflects the chemistry
of bedrock after comminution and dispersal. However, Ag and Hg have higher concentrations in the B-horizon soil where they were likely captured and concentrated by organic matter during soil formation. Till and soil size fraction analysis for metals
show that Au and Pb are present in soil and till as discrete mineral grains larger than 0.063 mm. Anomalous Co, Cu, Pb, Se, and Zn concentrations in till and soil define a ribbon-shaped dispersal train along the northern edge of the survey area. The
train formed from glacial erosion of mineralized bedrock, that was then transported and deposited by an east to west ice flow. This train was then subjected to post-glacial modification by colluvial processes. The trace element dispersal profiles
suggest a massive sulphide source for the anomalous metals in bedrock beneath the till at the east end of the dispersal train. Potentially, other till and soil Au and As anomalies in the western and southern parts of the survey area could have been
derived from unmapped, northeast-trending Au-quartz veins. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Il s'agit de la publication d'un ancien ensemble de données sur lequel le deuxième auteur (Paulen) a travaillé pendant qu'il travaillait pour la
British Columbia Geological Survey en 2000. Cet article examine un ensemble de données appariées d'échantillons de till et de sol sur un train de dispersion dans le centre de la Colombie-Britannique, de Quesnel. Les éléments de recherche sélectionnés
(pertinents pour l'exploration minérale) sont discutés dans cet article. La partie importante de cet article est de démontrer le plus grand rapport signal / bruit qui peut être détecté en échantillonnant le till, et pas seulement le sol.
L'échantillonnage du sol était une méthodologie historique utilisée dans l'exploration de la Cordillère. |
| GEOSCAN ID | 327571 |
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