The aim of this study is to investigate the nature of the meter-scale
cycles in the Ç / ayraz Formation of the Middle Eocene age and to study the
response of foraminifera to the sedimentary cyclicity. In order to perform this
study, two stratigraphic sections, which are 44,55 m and 25,95 m in thickness,
were measured on a regularly bedded succession mainly composed of
carbonates and siliciclastics in the Ç / ayraz Formation of the Haymana Basin.
In this study, detailed microfacies analyses were carried out in the
studied sections and 10 different microfacies types were identified strictly
based on the biofacies in order to define meter scale cyclic sedimentation.
Based on the detailed microfacies analysis and the distribution of the
vertical facies relationships a composite depositional model is suggested.
According to this model, three major facies associations were distinguished,
from deepest to shallowest, as: shallow open marine, shoal and lagoon.
Studied sections are composed of meter-scale cycles of both upward
shoaling or deepening in character and based on the stacking pattern of meterscale
cycles two systems tracts were identified along the measured sections.
Section 1 is represented by highstand systems tract (HST) and section 2 is
represented by lowstand systems tract (TST).
In this study, the responses of benthic foraminiferal groups to the
sedimentary cyclicity have been documented by quantitative and statistical
analysis to understand the shallowing upward cycles, which are fundamental
stratigraphic units, in the Ç / ayraz Formation of Middle Eocene age. Among
foraminifera, particularly the forms like Nummulites, Assilina and Discocyclina
are excellent in order to detect cyclic variations of facies. These studies lead to
understand shoaling-upward character of the meter-scale cycles, which are the
building blocks of the Ç / ayraz Formation.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12610161/index.pdf |
| Date | 01 December 2008 |
| Creators | Geyikcioglu Erbas, Bedia |
| Contributors | Altiner, Demir |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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