کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4696804 1637227 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nanoscale relationships between uranium and carbonaceous material in alteration halos around unconformity-related uranium deposits of the Kiggavik camp, Paleoproterozoic Thelon Basin, Nunavut, Canada
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی اقتصادی
پیش نمایش صفحه اول مقاله
Nanoscale relationships between uranium and carbonaceous material in alteration halos around unconformity-related uranium deposits of the Kiggavik camp, Paleoproterozoic Thelon Basin, Nunavut, Canada
چکیده انگلیسی


• Hydrothermal carbonaceous material (CM) associated with a Proterozoic U deposit
• First description of CM in the Thelon Basin area of Nunavut
• Unusual association of massive and disseminated CM with U oxide minerals
• Natural carbon nanoscale structures controlled crystal nucleation and growth

Concentrations of 7% U and 1% Cu were identified in massive, brecciated, and amorphous carbonaceous materials (CM) characterized by strongly negative values of carbon stable isotopes (δ13C = − 39.1‰ relative to PDB). The anomalies are restricted to clay alteration halos developed in Neoarchean Woodburn Lake group metagreywacke that is the predominant host of unconformity-related uranium (U) deposits in the Kiggavik exploration camp. Petrographic and microstructural analyses by SEM, X-ray Diffraction, HRTEM and RAMAN spectroscopy identified carbon veils, best described as graphene-like carbon, upon which nano-scale uraninite crystals are distributed. CMs are common in U systems such as the classic Cretaceous roll-front deposits and the world-class Paleoproterozoic unconformity-related deposits. However, the unusual spatial and textural association of U minerals and CM described herein raises questions on mechanisms that may have been responsible for the precipitation of the CM followed by crystallization of U oxides on its surfaces. Based on the characteristics presented herein, the CMs at Kiggavik are interpreted as hydrothermal in origin. Furthermore, the nanoscale organization and properties of these graphene-like layers that host U oxide crystallites clearly localized U oxide nucleation and growth.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ore Geology Reviews - Volume 79, December 2016, Pages 382–391
نویسندگان
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