• journal_title：The Canadian Mineralogist
• Contributor：Jennifer Peats ; Thomas Stachel ; Richard A. Stern ; Karlis Muehlenbachs ; John Armstrong
• Publisher：Mineralogical Association of Canada
• Date：2012-
• Format：text/html
• Language：en
• Identifier：10.3749/canmin.50.3.611
• journal_abbrev：Can Mineral
• issn：0008-4476
• volume：50
• issue：3
• firstpage：611
• section：Articles

Diamonds from Aviat, on the Melville Peninsula, Canada, display a range in δ¹³C from −30‰ to −2‰, with a prominent mode at −5‰. Strongly ¹³C-depleted diamonds indicate derivation from eclogitic sources and are likely related to precipitation from remobilized, subducted former organic matter. The main population of diamonds around −5‰ may be of eclogitic or peridotitic derivation. Complex CL patterns and abrupt variations in carbon isotopic composition (δ¹³C) indicate that at least three episodes of diamond growth occurred, separated by periods of resorption. Nitrogen concentration and δ¹³C are decoupled both on the level of individual growth-zones and for the bulk diamond data, indicating that either multiple sources of fluid contributed to diamond formation at Aviat or that nitrogen was fractionated through partitioning into potassium-bearing minerals. Nitrogen-based mantle-residence temperatures for Aviat diamonds mostly fall in the range ~1050–1150 ºC; projected on a syneruptive paleogeotherm of 38 mW/m² surface heat-flow, this indicates sampling over a narrow interval between ~150–170 km depth.