|Title:||Stream sediment geochemical/indicator mineral orientation survey, Lonnie Nb Prospect, British Columbia, Canada|
|Author(s):||Luck, P., Simandl, G.J.|
|NTS Map Sheet(s):||093N/09|
|Place Keyword(s):||British Columbia, central|
|Lat/Long (NSWE):||55.73, 55.65, -124.475, -124.27|
|Theme Keyword(s):||niobium, rare earth elements, carbonatite, indicator minerals, stream sediments|
The Lonnie carbonatite complex is the third most developed Nb prospect in the British Columbia alkaline province. The objective of this study was to determine the best size fraction of stream sediments for carbonatite related indicator mineral surveys. Sediments from seven sites along Granite Creek, a stream that transects the Lonnie deposit and adjacent bedrock units, were sampled for pXRF and pathfinder element studies. The results for key pathfinder elements including Nb, Ta, La, Ce, Pr, Nd, Y, P, Sr, Ba, Th, and U were precise (most having %RSD less than 5%) and prone to bias. Results for eight size fractions separated by laboratory sieves indicated a systematic distribution of key elements, with the highest abundances found in the finer size fractions. Of these, the +125Ám fraction was chosen for further consideration due to its suitability for continued indicator mineral studies. With the exception of Ba, Sr, and possibly Nb samples upstream from the Lonnie deposit display higher concentrations of carbonatite pathfinder elements than samples downstream of the deposit. This indicates source(s) farther upstream, probably the Vergil carbonatite and Nb and TREE + Y soil geochemical anomalies. Indicator mineral studies are ongoing.