کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4724407 1639705 2008 31 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Proterozoic deformation in the northwest of the Archean Yilgarn Craton, Western Australia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Proterozoic deformation in the northwest of the Archean Yilgarn Craton, Western Australia
چکیده انگلیسی
The Narryer Terrane within the northwestern Yilgarn Craton contains the oldest crust in Australia. The Jack Hills greenstone belt is located within the southern part of the Narryer Terrane, and structures cutting it and surrounding rocks have been dated using the 40Ar/39Ar technique. The results show that east-trending, dextral, transpressive shearing was related to the 1830-1780 Ma Capricorn Orogeny, followed by further deformation and/or cooling between c. 1760 and 1740 Ma. These results confirm that major deformation has affected the northwestern part of the Yilgarn Craton in an intracratonic setting during the Proterozoic. Proterozoic structures have been interpreted to extend south beyond the Narryer Terrane into the northern part of the Youanmi Terrane (Murchison Domain), and include the Yalgar Fault, previously interpreted as the boundary between the Narryer and Youanmi Terranes. Terrane amalgamation pre-dated the emplacement of c. 2660 Ma granites in both terranes, and the current expression of the Yalgar Fault must represent a younger, reworked, post-amalgamation structure, possibly controlled by the tectonic boundary. However, new aeromagnetic and gravity imagery does not show the eastern part of the Yalgar Fault as a major structure. Its signature is more akin to a series of east- to east-northeast trending faults that are interpreted to be Proterozoic in age. This suggests that this part of the Yalgar Fault may not be a terrane boundary, and is possibly no older than Proterozoic. The 40Ar/39Ar dating also shows a younger, less intense deformation and/or cooling event at c. 1172 Ma.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Precambrian Research - Volume 162, Issues 3–4, 1 May 2008, Pages 354-384
نویسندگان
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