Erdogmus-Yenigediz graben is one of the major structural elements of
Aksehir-Simav Fault System (ASFS), which is a major extensional
structure in the southwestern Anatolian extensional neotectonic
province (SWAEP). It is about 6-10-km-wide, 15-km-long and
approximately ENE-trending and is actively growing structure as
indicated by the 1970.03.28 (Mw= 7.2) Gediz earthquake.
The graben is characterized by two distinct units, separated by an
angular unconformity: (i) Miocene-middle Pliocene Arica formation and
(ii) Plio Quaternary Erdogmus formation. The former unit commences
with a basal conglomerate above the basement rocks and is composed
mainly of coal-bearing continental and lacustrine sediments with lava
flows and pyroclastics, particularly common in the middle parts of the
sequence. The volcanics are dated at 18.4 ± / 0.1 Ma (Ar-Ar mica ages).
They record evidence for two deformation phases as suggested by twosets of overprinting slickenlines, intense folding, thrust and strike-slip
faulting. The Erdogmus formation commences with terrace
conglomerates and is composed mainly of travertines, older and
younger alluvial deposits, fan-apron sediments and the recent axial
graben floor sediments.
Kinematic analysis of the graben-bounding normal faults, growth faults
within the graben-infill and those deforming the sediments are
consistent with three distinct phases of deformation: (i) Miocene middle
Pliocene extensional phase, (ii) interveining NE SW contractional phase
and (iii) Plio-Quaternary extensional phase. The data also suggests a
distributed stress field and a multi-directional recent extension in
predominantly NNE&ndash / SSW, E&ndash / W and NE&ndash / SW directions. This is also
consistent with available focal mechanism solutions for the region.
The graben therefore has an episodic evolutionary history with two
extensional phases and an intervening short-term contraction, as
described in many different parts of the SWAEP. The latter phase of
extension is considered as the part of Neotectonic regime, which
therefore commenced by the Late Pliocene.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613912/index.pdf |
| Date | 01 December 2011 |
| Creators | Gurboga, Sule |
| Contributors | Kocyigit, Ali |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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