Late Pleistocene Calcretes from Central Anatolia(Lakes Eymir and Mogan, G?lba?? Basin): Comparison to Quaternary Calcretes from Turkey

作     者：Ceren Kücükuysal Ceren Kücükuysal

作者机构：Mugla Sitki Kocman University Engineering Faculty Department of Geological Engineering Kotekli 48000 Turkey 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2016年第27卷第5期

页      面：874-882页

核心收录：

学科分类：070905[理学-第四纪地质学] 0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：supported financially by the General Directorate of Mineral Research and Exploration Turkey(No.2012-30-14-08-3) 

主　　题：calcrete micromorphology stable isotopes mineralogy Central Anatolia. 

摘      要：This study is the first to report the radiocarbon ages, mineralogical, morphological, geochemical and stable isotope compositions of calcretes from Neogene sediments around lakes Eymir and Mogan in the G？lba？？ Basin of Central Anatolia. Morphologically different forms of calcretes in the G？lba？？ Basin include powdery, nodular, fracture infill, laminar and hardpan types. Calcite is the dominant mineral of calcrete compositions; the diagnostic features of dessication cracks, random fractures, Mn O linings and dense sparitic infillings are observed. Chemical analyses show arid conditions with mean annual precipitation of 〈50 mm. δ13C compositions of the calcretes range from-6.77‰ to-9.32‰ PDB, typical for most pedogenic calcretes, reflecting the development under seasonally arid climates and C3-dominated vegetation cover. δ18O values are between-5.57‰ and-7.80‰ PDB, indicating the formation from meteoric water in a vadose zone environment. The results suggest that the Middle Pleistocene was arider and warmer, favouring the formation of palygorskite in association with the different forms of calcrete occurrences, whereas the Late Pleistocene was dryer and cooler, supporting the development of calcretes.