Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/117634
Citations | ||
Scopus | Web of Science® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | Magmatism and metamorphism at ca. 1.45 Ga in the northern Gawler Craton: the Australian record of rifting within Nuna (Columbia) |
Author: | Morrissey, L.J. Barovich, K.M. Hand, M. Howard, K.E. Payne, J.L. |
Citation: | Geoscience Frontiers, 2019; 10(1):175-194 |
Publisher: | China University of Geosciences (Beijing) and Peking University; Elsevier |
Issue Date: | 2019 |
ISSN: | 1674-9871 |
Statement of Responsibility: | Laura J. Morrissey, Karin M. Barovich, Martin Hand, Katherine E. Howard, Justin L. Payne |
Abstract: | U–Pb monazite and zircon geochronology and calculated metamorphic phase diagrams from drill holes in the northern Gawler Craton, southern Australia, reveal the presence of ca. 1.45 Ga magmatism and metamorphism. Magmatism and granulite facies metamorphism of this age has not previously been recognised in the Gawler Craton. The magmatic rocks have steep LREE-enriched patterns and high Ga/Al values, suggesting they are A-type granites. Calculated metamorphic forward models suggest that this event was associated with high apparent thermal gradients and reached pressures of 3.2–5.4 kbar and temperatures of 775–815 °C. The high apparent thermal gradients may reflect pluton-enhanced metamorphism, consistent with the presence of A-type granites. The recognition of ca. 1.45 Ga tectonism in the northern Gawler Craton is added to a compilation of ca. 1.50–1.40 Ga magmatism, shear zone reactivation, rift basin development and isotope resetting throughout the South and North Australian Cratons that shows that this event was widespread in eastern Proterozoic Australia. This event is stylistically similar to ca. 1.45 Ga A-type magmatism and high thermal gradient metamorphism in Laurentia in this interval and provides further support for a connection between Australia and Laurentia during the Mesoproterozoic. The tectonic setting of the 1.50–1.40 Ga event is unclear but may record rifting within the Nuna (or Columbia) supercontinent, or a period of intracontinental extension within a long-lived convergent setting. |
Keywords: | Gawler Craton; Laurentia; metamorphism; U-Pb geochronology; paleogeographic reconstruction |
Rights: | © 2018, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NCND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
DOI: | 10.1016/j.gsf.2018.07.006 |
Grant ID: | http://purl.org/au-research/grants/arc/LP160100578 http://purl.org/au-research/grants/arc/DP160104637 |
Published version: | http://dx.doi.org/10.1016/j.gsf.2018.07.006 |
Appears in Collections: | Aurora harvest 8 Geology & Geophysics publications |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
hdl_117634.pdf | Published Version | 7.39 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.