The study area comprises Çayirli, Harapaǧillari and Ortabel (ÇHO) districts in the Haymana town 25 km SW of the Ankara city. In this study, geologic setting, mineralogical and geochemical characteristics of manganese mineralizations are examined and their origin is discussed. Data were obtained from field observations, various polished and thin section determinations and chemical analyses of 25 ore samples. Major and trace element analyses were conducted with ICP-ES and ICP-MS methods at ACME Laboratories (Canada). ÇHO manganese ores are found in reddish radiolarites and partly interbedded marls of the Ankara ophiolitic melange of lower Cretaceous-upper Senonian age. In these extremely folded rocks, manganese is observed as band and lenses. All samples are composed of pyrolusite and quartz. Circular pyrolusites around the gangue form a ring texture and radiolarite ores yield spherical sections. In addition, breccia-like texture is observed between pyrolusite and quartz. Geologic setting, mineralogical and textural data indicate an exogene environment. Major and trace element abundances and correlation among them imply that ÇHO mineralizations are of hydrothermal origin and linked to the same source. Evaluation of all these data shows that ÇHO manganese mineralizations are of hydrothermal type sedimentary mineralization and they were deposited in distal part of the source.

The study field covering an area of about 1000 km 2 is located in Sorgun town of the city of Yozgat. In the region Paleozoic, Campanian-Maastrichtian, Eocene, Miocene and Quaternary units are exposed. Among these units, the lower Eocene Çeltek Formation is particularly noticeable with coal beds and hosts rocks known as the oil shale. The Eocene epoch is important for organic matter deposition as regard to oil and gas productivity and anoxic deposition conditions. In order to examine the p aleo-sedimentary conditions of oil shales in the study area and their relation to total organic carbon (TOC) contents and major-trace element characteristics, a number of 29 samples were collected from two boreholes and one measured stratigraphic section. Samples have TOC contents varying from 1.37 to 11.8 wt% (average 4.96 wt%). Using geochemical data on oil shales of the Çeltek Formation (ÇFOS) V/Cr, V/(V+Ni), U/Th, δU and authigenic uranium (AU) values were computed which revealed that oil shales have variable paleo-environment conditions. For paleo-salinity Sr/Ba ratios were estimated and found that samples were mostly deposited in freshwater environment. Chemical alteration index values (CIA) and Sr/Cu ratios indicate that paleo-climate conditions of ÇFOS were dry, hot and occasionally humid. Fe/Ti and (Fe+Mn)/Ti ratios reveal the existence of a hydrothermal activity during the sedimentation of oil shales. Zr/Rb ratios of samples are indicative of very weak p aleo-hydrodynamics during the deposition of oil shales. Such different geochemical conditions in the basin resulted in the regulation of variable paleo-environment conditions and water chemistry-environment-climate conditions and even changes in organic productivity at the lake level surface.

In this study, geochemical behavior of elements is investigated in 25 coal samples collected at 10 locations of Şahinli coaliferous units at southeast of Aydın, Turkey. In all the samples, X-ray powder diffraction and inductively coupled plasma mass spectrometry analyses were performed and element and mineral compositions were determined. Total organic carbon (TOC) values of coals are between 14.6 and 37.7 wt% with average of 28.5 wt%. Samples are composed of quartz, calcite, feldspar, dolomite, mica, gypsum, and salt minerals which are accompanied by illite-, kaolinite-, and smectite-type clay minerals. Comparison of average element contents of world coals and studied samples yields that K > Fe > As > U > Cs > Y > Er > Al > Th > Rb > Yb > W > Tb > Dy > Lu > Ce > Sm > La > Ho > Si > Nd > Gd > Tm > Eu > Nb > Pr > Pb > Sn > Ni > Cu > Ga > Ta > Sb > Zr > Cd > V > Zn > Co > Mo > P > Hf > Ba are found to be enriched, while Mn > Be > Ca > Sr > Bi > Mg are found to be depleted. Statistically elements are correlated with TOC.