Dataset Information

First Precambrian palaeomagnetic data from the Mawson Craton (East Antarctica) and tectonic implications.

ABSTRACT: A pilot palaeomagnetic study was conducted on the recently dated with in situ SHRIMP U-Pb method at 1134?±?9?Ma (U-Pb, zircon and baddeleyite) Bunger Hills dykes of the Mawson Craton (East Antarctica). Of the six dykes sampled, three revealed meaningful results providing the first well-dated Mesoproterozoic palaeopole at 40.5°S, 150.1°E (A₉₅?=?20°) for the Mawson Craton. Discordance between this new pole and two roughly coeval poles from Dronning Maud Land and Coats Land (East Antarctica) demonstrates that these two terranes were not rigidly connected to the Mawson Craton ca. 1134?Ma. Comparison between the new pole and that of the broadly coeval Lakeview dolerite from the North Australian Craton supports the putative ~40° late Neoproterozoic relative rotation between the North Australian Craton and the combined South and West Australian cratons. A mean ca. 1134?Ma pole for the Proto-Australia Craton is calculated by combining our new pole and that of the Lakeview dolerite after restoring the 40° intracontinental rotation. A comparison of this mean pole with the roughly coeval Abitibi dykes pole from Laurentia confirms that the SWEAT reconstruction of Australia and Laurentia was not viable for ca. 1134?Ma.

SUBMITTER: Liu Y

PROVIDER: S-EPMC6219563 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

First Precambrian palaeomagnetic data from the Mawson Craton (East Antarctica) and tectonic implications.

Liu Yebo Y Li Zheng-Xiang ZX Pisarevsky Sergei A SA Kirscher Uwe U Mitchell Ross N RN Stark J Camilla JC Clark Chris C Hand Martin M

Scientific reports 20181106 1

A pilot palaeomagnetic study was conducted on the recently dated with in situ SHRIMP U-Pb method at 1134 ± 9 Ma (U-Pb, zircon and baddeleyite) Bunger Hills dykes of the Mawson Craton (East Antarctica). Of the six dykes sampled, three revealed meaningful results providing the first well-dated Mesoproterozoic palaeopole at 40.5°S, 150.1°E (A<sub>95</sub> = 20°) for the Mawson Craton. Discordance between this new pole and two roughly coeval poles from Dronning Maud Land and Coats Land (East Antarct ...[more]

PMID: 30401799

Similar Datasets

Project description:The Longwangzhuang pluton is a typical example of Paleoproterozoic A-type granite intrusions at the southern margin of the North China Craton. This pluton is composed of arfvedsonite granite and minor aegirine-augite granites. Samples from both granite types display similar zircon U-Pb ages with 207U-206Pb ages of 1612?±?19?Ma [mean square weighted deviation (MSWD)?=?0.66] and 1609?±?24?Ma (MSWD?=?0.5), respectively. The granites exhibit similar high silica (SiO2?=?71.1-73.4 wt.%), high alkaline (Na2O?+?K2O?=?8.10-9.26 wt.%, K2O/Na2O?>?1), and low Al2O3 (11.8-12.8 wt. %) contents and metaluminous to weakly peraluminous bulk chemistry. The chemical variations of the Longwangzhuang pluton suggest the effects of mineral fractionation. In addition, all samples show typical characteristics of A-type granites, such as high 10000Ga/Al ratios (4.10-7.28), high FeOtot/(FeOtot?+?MgO) ratios (0.88-0.99), and high Zr (484-1082 ppm), Ce (201-560 ppm), and Y (78-156 ppm) contents. The ?Nd(t) values and the (206Pb/204Pb)t, (207Pb/204Pb)t, and (208Pb/204Pb)t ratios of the arfvedsonite granite samples vary from -4.6 to -5.3, 15.021 to 17.349, 15.241 to 15.472, and 33.206 to 36.905, respectively, and those for the aegirine-augite granite sample amount at -0.2, 14.421, 15.175, and 33.706. The distinct and variable Nd and Pb isotope values indicate the presence of heterogeneous protoliths. Based on its geochemistry, its low initial Pb isotope ratios, and its enrichment in Nd isotopes, we infer that the Longwangzhuang A-type granite is the partial melting product of basement rocks such as the Taihua Group gneisses accompanied by some involvement of juvenile material from the mantle. Together with published data from other Paleoproterozoic A-type granite plutons exposed at the southern margin of the craton, our findings suggest that these granites had a similar origin. Furthermore, geochemically, they can be divided into two groups: A2-type, which formed earlier (~1.8-1.6 Ga), and A1-type, which formed later (~1.6-1.5 Ga). Combining this information with the variations in whole-rock Nd and zircon Hf isotopic composition at ca. 1.6 Ga, we propose that tectonic transformation from post-orogenic to anorogenic magmatism occurred at the southern margin of the North China Craton at that time.

Dataset Information

First Precambrian palaeomagnetic data from the Mawson Craton (East Antarctica) and tectonic implications.

Publications

First Precambrian palaeomagnetic data from the Mawson Craton (East Antarctica) and tectonic implications.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets