scholarly journals Chemical studies of kimberlite indicator minerals from stream sediment and till samples in the southern Mackenzie region (NTS 85B, C, F, G), Northwest Territories, Canada

2021 ◽  
Author(s):  
I R Smith ◽  
S J A Day ◽  
R C Paulen ◽  
D G Pearson
Keyword(s):  
Rare Earth ◽  
Northwest Territories ◽  
Stream Sediment ◽  
Chemical Analyses ◽  
Great Slave Lake ◽  
Chemical Studies ◽  
Kimberlite Indicator Minerals ◽  
Indicator Mineral ◽  
Indicator Minerals ◽  
Field Area

Till (n=196) and stream sediment (n=60) samples were collected in the area south and west of Great Slave Lake, Northwest Territories (NTS 85B, C, F, and G), over the course of 3 summer field seasons. Samples were processed to recover kimberlite and other indicator minerals. This report summarizes results of the kimberlite indicator mineral (KIM) studies, including measures of KIM mineral types, abundances, and chemistry (major, trace, and rare earth elements). KIMs were present in 24% of the samples collected, and only 183 KIM grains in total were recovered, of which Cr-pyrope garnets were the most abundant (65.6%). Chemical analyses revealed strong similarities to the Drybones Bay and Mud Lake kimberlites which are situated 50 to >100 km to the northeast, roughly aligned with prominent glacially streamlined landform flowsets in this field area. Results suggest there is little evidence for undetected kimberlite outcrop or sub-crop in the study area.

Overview of surficial geochemistry and indicator mineral surveys and case studies from the Geological Survey of Canada's GEM Program

2021 ◽  
pp. geochem2021-070
Author(s):  
M.B. McClenaghan ◽  
W.A. Spirito ◽  
S.J.A. Day ◽  
M.W. McCurdy ◽  
R.J. McNeil ◽  
...  
Keyword(s):  
Northwest Territories ◽  
Case Studies ◽  
Stream Water ◽  
Regional Scale ◽  
Stream Sediment ◽  
Geological Survey ◽  
Ice Flow ◽  
Northern Canada ◽  
Indicator Mineral ◽  
Indicator Minerals

The Geological Survey of Canada carried out reconnaissance-scale to deposit-scale geochemical and indicator-mineral surveys and case studies across northern Canada between 2008 and 2020 as part of its Geo-mapping for Energy and Minerals (GEM) program. In these studies, surficial geochemistry was used to determine the concentrations of up to 65 elements in various sample media including lake sediment, lake water, stream sediment, stream water, or till samples across approximately 1 000 000 km2 of northern Canada. As part of these surficial geochemistry surveys, indicator mineral methods were also used in regional-scale and deposit-scale stream sediment and till surveys. Through this program, areas with anomalous concentrations of elements and/or indicator minerals that are indicative of bedrock mineralization were identified, new mineral exploration models and protocols were developed, a new generation of geoscientists was trained, and geoscience knowledge was transferred to northern communities. Regional- and deposit-scale studies demonstrated how transport data (till geochemistry, indicator mineral abundance) and ice-flow indicator data can be used together to identify and understand complex ice flow and glacial transport. Detailed studies at the Izok Lake Zn-Cu-Pb-Ag VMS, Nunavut, the Pine Point carbonate-hosted Pb-Zn in the Northwest Territories, the Strange Lake REE deposit in Quebec and Labrador as well as U-Cu-Fe-F and Cu-Ag-Au-Au IOCG deposits in the Great Bear magmatic zone, Northwest Territories demonstrate new suites of indicator minerals that can now be used in future reconnaissance- and regional-scale stream sediment and till surveys across Canada.

Ultrabasic eruptives with alnöitic-kimberlitic affinities from Malaita, Solomon Islands

1965 ◽  
Vol 34 (268) ◽  
pp. 16-34 ◽  
Author(s):  
J. B. Allen ◽  
T. Deans
Keyword(s):  
Solomon Islands ◽  
Chemical Analyses ◽  
Alkaline Rocks ◽  
Kimberlite Indicator Minerals ◽  
Host Rocks ◽  
Indicator Minerals

SummaryA detrital assemblage of magnesian ilmenite, pyrope, chrome-diopside, rutile, and zircon has been traced to outcropping ultrabasic alkaline rocks, hitherto unknown in the Melanesian region. Analyses and descriptions of these ‘kimberlite indicator minerals’ are given. The host rocks comprise alnöite, an alnöite breccia with calcite matrix, and a magnesian ankaratrite, which are described, with chemical analyses. Emphasis is laid on the abundance of ultrabasic inclusions and xenocrysts and the replacements and transformations they have undergone. Malaita Island promises to contribute significantly to the understanding of the relations between alnöite, melilite basalts, and kimberlites.

Observations on the Proterozoic Seton Formation, East Arm of Great Slave Lake, Northwest Territories

1972 ◽  
Vol 9 (9) ◽  
pp. 1110-1123 ◽  
Author(s):  
M. A. D. Olade ◽  
R. D. Morton
Keyword(s):  
Northwest Territories ◽  
Volcanic Rocks ◽  
Chemical Analyses ◽  
Quartz Porphyry ◽  
Shallow Marine ◽  
Hypabyssal Intrusions ◽  
Lake Region ◽  
Great Slave Lake ◽  
Marine Sedimentation ◽  
Partial Chemical

The Proterozoic (Aphebian) Seton Formation is shown to extend across almost the entire length of the East Arm structural subprovince of the Great Slave Lake region, Northwest Territories. Earlier described as greenstones or basalts and recently as an andesite–rhyolite suite, the volcanic rocks which characterize the Seton Formation are clearly of spilitic–keratophyric affinity. The formation is composed of a sequence of marine to subaerial, spilitic basalt flows, trachytic flows, quartz keratophyric–and spilitic–basic pyroclastics, volcanic sandstones, jasper, banded ironstones, and intercalated marine epiclastic sedimentary rocks. Small hypabyssal intrusions of albite granophyre, albite, and quartz porphyry represent minor subvolcanic phases. Petrographic descriptions of the lavas and pyroclastic rocks from Toopon Lake, the Fort Reliance area, and Seton Island are augmented by partial chemical analyses of 15 lavas from the latter locality. The volcanic–sedimentary Seton Formation, 1300 m thick in the SW of the East Arm, and 40 m thick in the Fort Reliance district, should be classified as a member of the Sosan Group, being in part laterally equivalent to the Akaitcho River Formation and the upper Kluziai Formation. The Aphebian Coronation Geosyncline during Seton times was thus characterized by effusive (partially submarine) island volcanism in the SW of the region, contemporaneous with shallow marine sedimentation towards the northeast part of the basin.

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