A magnetotelluric investigation of the Arabia-Eurasia collision in eastern Anatolia

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" A magnetotelluric investigation of the Arabia-Eurasia collision in eastern Anatolia "
Ersan Turkoglu

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	55276
Doc. No	:	TL25230
Call number	:	‭NR55625‬
Main Entry	:	Ersan Turkoglu
Title & Author	:	A magnetotelluric investigation of the Arabia-Eurasia collision in eastern Anatolia\ Ersan Turkoglu
College	:	University of Alberta (Canada)
Date	:	2009
Degree	:	Ph.D.
student score	:	2009
Page No	:	235
Abstract	:	Eastern Anatolia is the location of a young continent--continent collision between the Arabian and Eurasian plates in Eastern Turkey. The first long-period magnetotelluric (MT) data were collected in eastern Anatolia in 2005 as part of this thesis. These MT data have been used to image the electrical resistivity of the crust and upper mantle as well as the continental boundaries. Two and three-dimensional inversion algorithms were used to obtain resistivity models of the study area. The MT inversion models indicate that the Anatolian Block is characterized by a low-resistivity (10-30 Ωm) fluid-rich lower crust underlain by relatively normal upper mantle structure. The Anatolian Plateau has a lower crust that contains pockets of very low resistivity (2-5 Ωm) that may indicate local accumulations of melt. These pockets require at least 5-14% of partial melt to account for the observed bulk resistivities. The lower crust is underlain by an upper mantle with an anomalously low resistivity that can be accounted for by an asthenosphere containing ∼2% percent partial melt. The presence of fluids along with high temperatures may weaken the crust and mantle sufficiently to permit lateral flow, and may also allow a decoupling of the upper and lower portions of the lithosphere. South of the Bitlis Suture Zone, the depth of the lithosphere-asthenosphere boundary on the Arabian foreland was found to be around 110 km from constrained MT inversions. The average resistivity of the Arabian lithosphere is 100-300 Ωm which is one order of magnitude higher than the Anatolian Plateau. A fault zone conductor observed beneath the East Anatolian Fault at Hazar Lake correlates with a band of low seismicity and may represent a weak segment of the fault that is creeping. The thickness of the Erzincan Basin was found to be 3±0.25 km with a slight (0.25 km) increase towards the western part of the basin. The lithospheric structure of the Anatolian Plateau is similar to that of the northern Tibetan Plateau, with zones of inferred elevated fluid content. However, low resistivity in the Anatolian crust is found in isolated pockets, rather than the widespread regions observed in Tibet.
Subject	:	Earth sciences; Arabia-Eurasia collision; Continent-continent collisions; Electrical resistivity; Anatolian Plateau; Upper mantle; Geophysics; Plate Tectonics; 0592:Plate Tectonics; 0373:Geophysics
Added Entry	:	University of Alberta (Canada)