Multiproxy evidence of Mid-Pleistocene dry climates observed in calcretes in Central Turkey

Date

2013-01-01

Author

Kucukuysal, Ceren
Günal Türkmenoğlu, Asuman
Kapur, Selim

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

68
views

0
downloads

Palaeosols are very important in reconstructing palaeoclimate studies, since they are accepted as useful climate markers and as potential providers of proxy data. The study of the palaeosols of the Plio-Pleistocene rock sequences around Ankara revealed evidence for a reconstruction of the Quaternary palaeoclimate of the region. The study area is located in Bala, south-east of Ankara, which contains Middle Pleistocene red palaeosols with powdery to nodular calcrete developments, alternating with channel deposits. During this warm and arid period in the Pleistocene, the limited water available in the soil led to the accumulation of low magnesian carbonates, forming calcretes. The clay fractions of the samples were X-rayed using air-drying, ethylene-glycol solvation and heating treatments. The clay mineral contents were determined as smectite, kaolinite, illite and chlorite. Palygorskite was also identified. In the relative abundances of clay minerals, smectite, the most abundant clay mineral, is depleted towards the upper part of the section while the amount of palygorskite increases. Since palygorskite is the only pedogenic mineral formed during the Pleistocene, its presence can be accepted as evidence of the dominant arid climatic conditions. The isotopic composition of carbonates in the Bala section exhibits a slightly wider range in delta C-13 composition from -5.98% to -9.22% and a narrower range in delta O-18 composition from -7.19% to -8.66%. The carbon isotope values clearly imply that arid to semiarid flora C4 is dominant, with C3:C4 mixed vegetation. This study suggests that the Middle Pleistocene is the time of the Mid-Brunhes Event when the dominantly warm climatic temperatures led to the development of calcretes in Bala, Ankara, as with all Quaternary Mediterranean-type calcretes.

Subject Keywords

Quaternary, Ankara, Arid climate, Calcrete, Palygorskite, Palaeosol, Clay minerals, Pedogenic

URI

https://hdl.handle.net/11511/47085

Journal

TURKISH JOURNAL OF EARTH SCIENCES

DOI

https://doi.org/10.3906/yer-1201-5

Collections

Department of Geological Engineering, Article

Suggestions

OpenMETU
Core

Weighted multi-visibility analysis on directional paths Şeker, Çağıl; Toprak, Vedat; Department of Geodetic and Geographical Information Technologies (2010) Visibility analysis is an important GIS tool that is used in a diverse array of disciplines ranging from earth sciences to telecommunications. Multi-visibility, as a cumulative type of visibility, combines many point-to-point results into a multi-value array. Points, lines, or areas can be used as sources or targets; and the combined values can be calculated in both ways. Through multi-visibility, a special 2.5D visibility value surface can be constructed over a digital elevation model. The effectiveness of...
An overview of detection in MIMO radar Bilgi Akdemir, Şafak; Candan, Çağatay; Department of Electrical and Electronics Engineering (2010) In this thesis study, an overview of MIMO radar is presented. The differences in radar cross section, channel and received signal models in different MIMO radar configurations are examined. The performance improvements that can be achieved by the use of waveform diversity in coherent MIMO radar and by the use of angular diversity in statistical MIMO radar are investigated. The optimal detector under Neyman-Pearson criterion for Coherent MIMO radar when the interfering signal is white Gaussian noise is devel...
Seismic Microzonation of Erbaa, Tokat Province, Turkey, Based on Analytical Hierarchical Process Akin, Muge K.; Topal, Tamer; Kramer, Steven L. (2012-05-01) This study is to develop a seismic microzonation map using Analytical Hierarchical Process (AHP), one of the Multicriteria Decision Analysis methods based on Geographical Information Systems. The study area, Erbaa, is located along the eastern segment of the North Anatolian Fault Zone and is one of the largest towns and one of 12 districts within Tokat Province (population, similar to 176,000) in the Middle Black Sea Region of Turkey. Erbaa is located on the southwest bank of the Kelkit River. After the dis...
The use of nuclear techniques in source apportionment studies, exemplified by recent studies in Turkey GÜLLÜ, GÜLEN; Tuncel, Süleyman Gürdal (2004-01-01) Nuclear analytical methods are very important atmospheric tools as they provide multielement data, which is essential for receptor modeling. In this study, the application of receptor modeling is discussed on rural data to determine source regions affecting chemical composition of aerosols in the Eastern Mediterranean. The factor analysis revealed 4 sources, two of which represent anthropogenic component in aerosol mass. The source regions that determine the composition of particles is investigated using tr...
Clustering of manifold-modeled data based on tangent space variations Gökdoğan, Gökhan; Vural, Elif; Department of Electrical and Electronics Engineering (2017) An important research topic of the recent years has been to understand and analyze data collections for clustering and classification applications. In many data analysis problems, the data sets at hand have an intrinsically low-dimensional structure and admit a manifold model. Most state-of-the-art clustering methods developed for data of non-linear and low-dimensional structure are based on local linearity assumptions. However, clustering algorithms based on locally linear representations can tolerate diff...

Citation Formats

C. Kucukuysal, A. Günal Türkmenoğlu, and S. Kapur, “Multiproxy evidence of Mid-Pleistocene dry climates observed in calcretes in Central Turkey,” TURKISH JOURNAL OF EARTH SCIENCES, pp. 469–483, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47085.