An isotopic perspective on growth and differentiation of Proterozoic orogenic crust: From subduction magmatism to cratonization

Journal Article · Sun Jan 01 04:00:00 EST 2017 · Lithos

DOI:https://doi.org/10.1016/j.lithos.2016.11.003· OSTI ID:1339796

Johnson, Simon P.; Korhonen, Fawna J.; Kirkland, Christopher L.; Cliff, John B.; Belousova, Elena A.; Sheppard, Stephen

The in situ chemical differentiation of continental crust ultimately leads to the long-term stability of the continents. This process, more commonly known as ‘cratonization’, is driven by deep crustal melting with the transfer of those melts to shallower regions resulting in a strongly chemically stratified crust, with a refractory, dehydrated lower portion overlain by a complementary enriched upper portion. Since the lower to mid portions of continental crust are rarely exposed, investigation of the cratonization process must be through indirect methods. In this study we use in situ Hf and O isotope compositions of both magmatic and inherited zircons from several felsic magmatic suites in the Capricorn Orogen of Western Australia to highlight the differentiation history (i.e. cratonization) of this portion of late Archean to Proterozoic orogenic crust. The Capricorn Orogen shows a distinct tectonomagmatic history that evolves from an active continental margin through to intracratonic reworking, ultimately leading to thermally stable crust that responds similarly to the bounding Archean Pilbara and Yilgarn Cratons.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1339796
• Report Number(s): PNNL-SA-119918; KP1704020
• Journal Information: Lithos, Journal Name: Lithos Vol. 268-271; ISSN 0024-4937
• Country of Publication: United States
• Language: English