scholarly journals K - Ar [Hornblende] Data From the Healey Lake area, District of Mackenzie: a Potential Time Constraint On the Intracratonic Indentation of the Slave Province Into the Thelon Tectonic Zone

1991 ◽  
Author(s):  
J B Henderson ◽  
O Van Breemen
Keyword(s):  
Time Constraint ◽  
Lake Area ◽  
Tectonic Zone ◽  
Slave Province

Temporal distribution of granitoid plutonic rocks in the Archean Slave Province, northwest Canadian Shield

1992 ◽  
Vol 29 (10) ◽  
pp. 2186-2199 ◽  
Author(s):  
O. van Breemen ◽  
W. J. Davis ◽  
J. E. King
Keyword(s):  
Continental Margin ◽  
Temporal Distribution ◽  
Lake Area ◽  
Margin Setting ◽  
General Terms ◽  
Slave Province ◽  
Age Variation ◽  
Granitoid Rocks ◽  
Plutonic Rocks ◽  
Granitoid Gneisses

Granitoid rocks in the Slave Province consist of 4.0–2.8 Ga granitoid gneisses that predate the 2.71–2.65 Ga volcanic and turbiditic rocks of the Yellowknife Supergroup and 2.70–2.58 Ga granitoid plutons that intrude the Yellowknife Supergroup. U–Pb zircon ages and Nd and Pb isotopic data indicate that the older granitoids are restricted to the western part of the Slave Province. Granitoid gneisses in the eastern Slave Province, previously suspected to predate the Yellowknife Supergroup, are similar in age to the volcanic rocks.In this paper, the results of a detailed geochronological study of plutonic rocks of the Contwoyto Lake – Nose Lake area of the northcentral Slave Province are reviewed and integrated with the available age data base for plutonic rocks elsewhere in the Slave Province. The data indicate that the timing of the later (<2.7 Ga) plutonism is bimodal, consisting of two distinct magmatic periods separated by approximately 20 Ma of apparent magmatic quiescence. The first period was synvolcanic, dating from 2695 to 2650 Ma. The second period, during which more than 80% of the granitoids presently exposed in the Slave Province were intruded, lasted from 2625 to 2580 Ma, spanning the major Archean deformation events, Syndeformation granitoids, with ages between 2625 and 2595 Ma, are dominantly diorite and tonalité in composition. Late- to post-deformation granitoid rocks, with ages between 2605 and 2580 Ma, range in composition from megacrystic biotite granodiorite to two-mica granite. In general terms, the compositions of the granitoid plutons vary in time from dominantly metaluminous to more strongly peraluminous.Present data show no obvious regional age variation among the younger granitoid rocks across the province. This apparent absence of diachroneity has important implications for models interpreting the magmatism as having evolved in a continental-margin setting, because the extent of contemporaneous plutonism is more than 400 km across strike, considerably broader than in most Mesozoic continental-margin batholiths.

Lead- and sulfur-isotope ratios from the Great Slave Lake area, Canada

1968 ◽  
Vol 5 (5) ◽  
pp. 1269-1276 ◽  
Author(s):  
D. K. Robertson ◽  
G. L. Cumming
Keyword(s):  
Lead Isotope ◽  
Sulfur Isotope ◽  
Isotope Ratios ◽  
Ore Deposits ◽  
Lake Area ◽  
Iron Sulfides ◽  
Tectonic Event ◽  
Slave Province ◽  
Great Slave Lake ◽  
Lead Line

Lead- and sulfur-isotope ratios have been determined for some galenas and iron sulfides from two regions around Yellowknife, Northwest Territories. For the ore deposits, sulfur-isotope ratios are close to the meteoritic value or slightly positive. Lead-isotope ratios fall into two groups, one derived from a source with Th/U = 4.3 and μ = 9–11, and the other from a source with Th/U = 3.5 and μ = 9.0. The ratios fall on an anomalous lead line, which indicates one event of great antiquity (approximately 4000 m.y.), and another about 2800 m.y. ago.Other sulfide samples from areas around Great Slave Lake, primarily outside the ancient (2800 m.y.) Slave Province, indicate events at 2800 m.y. and 1550 m.y., the latter date probably representing the time of the last major tectonic event in the Slave Province. Sulfur-isotope ratios for these samples vary from +1‰ to −13‰ relative to the meteoritic value, suggesting that these leads may have been remobilized by thermal metamorphism, and recombined with crustal sulfur enriched in 32S.

scholarly journals Timing and provenance of Paleoproterozoic supracrustal rocks in the central Thelon tectonic zone, Canada: implications for the tectonic evolution of western Laurentia from ca. 2.1 to 1.9 Ga

2021 ◽  
pp. 1-18
Author(s):  
W.J. Davis ◽  
M. Sanborn-Barrie ◽  
R.G. Berman ◽  
S. Pehrsson
Keyword(s):  
Detrital Zircon ◽  
Foreland Basin ◽  
Tectonic Zone ◽  
Zircon Age ◽  
Slave Craton ◽  
Magmatic Arc ◽  
Tectonic Model ◽  
Metasedimentary Rocks ◽  
Clastic Rocks ◽  
Slave Province

Depositional ages and provenance of metasedimentary rocks provide constraints on the architecture of the interface between the Slave and Rae cratons and processes related to the Thelon Orogen. Clastic rocks analysed from the central Thelon tectonic zone are Paleoproterozoic in age and not remnants of the Archean Yellowknife Supergroup (Slave Province), as originally considered. Two assemblages are recognized. An older clastic assemblage deposited after 2.09 Ga contains detrital zircon age modes of 2.3 and 2.17 Ga, with subordinate Neoarchean and Paleoarchean detritus. Its deposition is interpreted to predate Thelon magmatic activity given that (1) it lacks ca. 2.01–1.97 Ga detritus of Thelon magmatic origin, and (2) correlative clastic rocks occur as inclusions in Thelon plutons and contain ca. 2.0 Ga metamorphic monazite. This assemblage is correlative with both the Mary Frances and Rutledge River groups, establishing a >800 km long basin at ca. 2.1 Ga that received detritus from the western Rae and (or) Buffalo Head terrane(s). Separation from the Slave craton at this time is consistent with the absence of any Slave-affinity detritus. A younger assemblage deposited after 1.95 Ga and prior to 1.91 Ga contains mainly 2.02–1.95 Ga detrital zircon, age modes comparable with adjacent Thelon convergent-margin plutonic rocks. The younger assemblage records deposition of the uplifted and eroded Thelon magmatic arc in an intermontane or foreland basin setting during the later stages of post-collisional convergence. These U–Pb zircon data support a tectonic model for western Laurentia that reconciles differences between the Thelon and Taltson magmatic zones involving ca. 2.1 Ga rifting, ca. 2.01–1.97 Ga convergence, followed by <1.95 Ga thrust-driven exhumation.

Regional and local ice-flow history in the vicinity of the Izok Lake Zn–Cu–Pb–Ag deposit, Nunavut

2013 ◽  
Vol 50 (12) ◽  
pp. 1209-1222 ◽  
Author(s):  
Roger C. Paulen ◽  
M. Beth McClenaghan ◽  
Anna K. Hicken
Keyword(s):  
Lake Area ◽  
Massive Sulphide Deposit ◽  
Sulphide Deposit ◽  
Ice Flow ◽  
North Central ◽  
The North ◽  
Slave Province ◽  
Lake Region ◽  
Volcanogenic Massive Sulphide ◽  
Indicator Mineral

Ice-directional indicators were compiled from detailed field mapping at the Izok Lake volcanogenic massive sulphide deposit, in the Point Lake region of western Nunavut and eastern Northwest Territories. Cross-cutting erosional relationships and depositional landforms indicate that the Izok Lake area was affected by four ice-flow phases. It is this new glacial history interpretation that is used to explain the gahnite indicator mineral dispersal train down-ice of the Izok Lake deposit as being the net effect of all ice-flow phases. Its fan-shaped morphology is a function of the duration and intensity of two dominant glacial trajectories. Field-based mapping of all glacial-flow indicators are essential, and must be properly interpreted, to detect palimpsest dispersal trains. The resultant dispersal fan serves as a model for future exploration in the glaciated terrain of the north-central part of the Slave Province.

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