کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4693551 1636867 2010 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the geodynamics of the Aegean rift
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
On the geodynamics of the Aegean rift
چکیده انگلیسی

The Aegean rift is considered to be either a classic backarc basin, or the result of the westward escape of Anatolia, or the effect of a gravitational collapse of an over-thickened lithosphere. Here these models are questioned. We alternatively present a number of geodynamic and magmatic constraints suggesting a simple model for the genesis of the extension as being related to the differential advancement of the upper lithosphere over a heterogeneous lower African plate. The Greek microplate overrides the Ionian oceanic segment of the African plate faster than the Anatolian microplate over the thicker Levantine more continental segment. This setting is evidenced by GPS-velocity gradient in the hangingwall of the Hellenic–Cyprus subduction system and requires a zone of rifting splitting the hangingwall into two microplates. This mechanism is unrelated to the replacement of retreated slab by the asthenosphere as typically occurs in the backarc of west-directed subduction zones. The supposed greater dehydration of the Ionian segment of the slab is providing a larger amount of fluids into the low velocity channel at the top of the asthenosphere, allowing a faster decoupling between the Greek microplate and the underlying mantle with respect to the Anatolian microplate. Slab ruptures associated with the differential retreat controlled by the inherited lithospheric heterogeneities in the lower plate and the proposed upwelling of the mantle suggested by global circulation models would explain the occurrence and coexistence of slab-related and slab-unrelated magmatism.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volume 488, Issues 1–4, 5 June 2010, Pages 7–21
نویسندگان
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