Volume 159 / 2019

Early–middle Miocene reefal limestones are overlain disconformably by late Serravallian– early Tortonian incised valley-fi ll deposits of Dağpazarı formation in the Mut Basin. Dağpazarı formation is composed of mudstone, siltstone, sandstone and conglomerates. Facies associations of the formation are: fl uvial, lagoon, shoal-water delta, shoreface, beach and barrier island deposits. Loxoconcha tumida Brady and Loxoconcha sp. in the gray mudstones indicate the freshwater infl uence and decrease in salinity. Hemicyprideis sp. documents brackish water conditions. The shoreface sandstones alternating with the lagoonal mudstones, and oyster-rich beach deposits in different levels of the sequence indicate episodes of marine connections. The age of the Dağpazarı formation is provided by the planktonic foraminifera from the marine mudstones and marls below and above the formation, and corresponds to the MMi8–MMi10 biostratigraphic interval, which spans the late Serravallian–early Tortonian. Late Serravallian eustatic sea-level fall caused to the quick shallowing of the Mut Basin and subaerial exposure of the reefal limestones at the basin margin. Thus, the incised valley, formed upon the reefal limestones of the Mut formation. This incised valley refl ects a regional forced regression and unconformity. The Dağpazarı formation was deposited within this incised valley following an early Tortonian relative sea-level rise. https://doi.org/10.19111/bulletinofmre.501543

The Yenice-Gönen Fault (YGF) is located in the central part of the Biga Peninsula between Gönen and Yenice and is a right-lateral strike-slip active fault with general trending N65°E. On 18 March 1953 there was an earthquake on the YGF that died 263 people (Ms=7.2) and a 70 km surface rupture developed during this earthquake. In this study measurements of slip distribution were performed on the surface rupture of the Yenice-Gönen Earthquake (YGE) and the annual slip rate on the YGF was calculated. Right-lateral displacements of between 1.70±0.1 and 3.20±0.2 metres were measured on the surface rupture of the YGE. The maximum displacements were in an area close to the central part of the YGF (between Çakır and Karaköy village) and these values decreased relatively in NE and SW directions, documenting that was the bilaterally surface rupture propogation during the YGE. In the last 300.000 years, a total offset of 800±50 metres was measured on Gönen River and annual slip rate of 2.65±0.15 mm was calculated along the YGF. Current GPS studies show right-lateral strike-slip faults in the South Marmara region have slip rates of 6-8 mm/year. This slip rate is assessed as being partitioned between the YGF, Sarıköy Fault and Çan-Biga Fault zones which represent extensions of the North Anatolian Fault system within the South Marmara region. Paleoseismology studies determined that in the last 6200 years 6 earthquakes resulting in surface ruptures have occurred on the YGF, including the 1953 earthquake. According to the 14C and OSL dating results, the variable and irregular earthquake recurrence interval of YGF is ranging from 505 to 1793 years. In this study average earthquake recurrence interval of YGF was determined as 1180 years. https://doi.org/10.19111/bulletinofmre.500553

Instrumental and historical earthquake catalogues have to be examined and evaluated to understand the long-term seismic behaviour of active faults. Although the instrumental records have been determined from the national and international observatories, the historical seismic catalogues are very limited in Turkey. For the reason, we aimed to compile paleoseismological trench studies carried out before 2012 in the areas of onshore and offshore sections of Turkey. In terms of a Turkey Paleoseismological Project (TURKPAP) posted by General Directorate of Mineral Research and Exploration (MTA) in the 2012 year, a number of paleoseismological investigations have been initiated and documented for archiving at a standardized data layout. In this study, we compiled all paleoseismological trench surveys with the definite dates of past strong seismic events occurred in Turkey before that date. By using this compilation, not only the historical earthquakes but also many paleoseismologic parameters of the studies have been listed clearly. https://doi.org/10.19111/bulletinofmre.561925

In this study, the genus Alveolina D’ Orbigny, 1826 and its Alveolina (Alveolina) D’ Orbigny, 1826 and Alveolina (Glomalveolina) Hottinger, 1960 subgenera were re-examined and identified. Systematics of the subgenera Alveolina (Alveolina)=Alv. (Alv.) and Alveolina (Glomalveolina)=Alv.(Glomalv.) have also been reviewed and revised. Alv. (Glomalv.) is considered as a subgenus, not a genus (?). Because, all the generic features of microspheric generations (fB) of these two subgenera are identical. Thus, Alveolina D’ Orbigny, 1826 and Glomalveolina Hottinger, 1960 cannot be used as if they were two different genera (?). Otherwise Glomalveolina would be the synonym of Alveolina in “Systematic Paleontology” chapter. Therefore, Alv. (Alv.) and Alv. (Glomalv.) are both subgenusses, and the structural difference between these subgenera is observed seen in their megalospheric generations (fA). Besides, description of the genus (?) Glomalveolina has never been made in any of the studies in which Glomalveolina is referred as genus (?). However, the subgenus Alv. (Glomalv.) has incorrectly been used by many authors as “genus (?) Glomalveolina Hottinger, 1960 or 1962”. https://doi.org/10.19111/bulletinofmre.501688

Yarpuz-Kaypak (Osmaniye) region, located in Amanos Mountains, contains harzburgitic tectonites and mafic cumulates. The tectonites are represented by serpantinized harzburgites, whereas the cumulates are characterized by gabbronorite and gabbro compositions. The crystallization order within the cumulates is clinopyroxene, orthopyroxene plagioclase and amphibole. The major element compositions of the tectonites and cumulate rocks are consistent with formation in an arc-related tectonic setting. Trace element concentrations of these rocks exhibit large ion litophile element enrichments. Both geochemical and petrographic evidence suggest that the tectonite and cumulate rocks from the Yarpuz-Kaypak (Osmaniye) region represent the remnants of an oceanic lithosphere that formed in a supra-subduction zone tectonic setting during the closure of the Southern Neotethyan ocean and emplaced onto the northern margin of the Arabian platform in Late Cretaceous. https://doi.org/10.19111/bulletinofmre.501393

As a result of complex studies - geological-structural, morphostructural analytical, mineralogical mapping of quartz formations, detailed geochemical work and analysis of geochemical fields – forecasting prospecting features of gold ore taxon’s: ore zone; ore field; deposit and ore body. They are characterized by groups of criteria: morphostructural, stratigraphic-lithological, structural-tectonic, magmatic, geophysical, metasomatic, mineralogical, geochemical factors and attributes, and a geological-genetic model of the gold-bearing ore-forming system in the collapse zone. Favorable geological and structural conditions for the localization of gold mineralization in the mountains of Karakchatau are associated with the areas of long-term tectonic-magmatic activation in metalliferous sediments of Є-О contrast lithological composition. The coincidence of manifestations of gold mineralization to the blocks formed by transverse faults at the sites where they intersected the Karakchatau crush zone was noted. To the channel-localizing parts inside are blocky and unextended interblock tectonic structures with positions in favorable “structural traps” in their azimuthal curvatures of executed productive types of hydrothermal, sulfidizing quartz. The results of mineralogical mapping of quartz formations along the Karakchatau crush zone (Western Uzbekistan) are considered. Five genetic types of quartz are distinguished. The most productive of them is hydrothermal quartz of types 3 and 4 associated with pyrite,arsenopyrite and gold, which forms vein fields in areas of kinks and expansion of the zone of crushing. Identification of any goods and services that can be used for commercial purposes, including in the geological structure, other regions of Western Uzbekistan. https://doi.org/10.19111/bulletinofmre.432046  

The Rare Earth Elements (REE) deposits and mineralization of Turkey can be divided into four types based on their geological setting and origin. First are deposits associated with carbonatite- alkaline magmatic rocks, rich in Light Rare Earth Elements (LREE). The best known examples are the Kızılcaören (Eskişehir) and Kuluncak (Malatya) deposits with TREE grades of 2.9% and 0.7% respectively, and typical enrichment of La-Ce. Lower grade REE mineralization at Keban (0.05% TREE) and Divriği (0.13% TREE) is associated with abundant fluorite and all four occurrences show similar ranges for homogenization temperatures and salinities for fluid inclusions in fluorite and REE profiles. The second type are Triassic shales and the bauxites formed from them in the Bolkardağı region. Enrichment of Heavy REE (HREE) is typical and TREE grades are about 0.15% in bauxites and its protolith. These occurrences are geochemically similar to “ion adsorption type” deposits associated with lateritic clay on the weathered granitic rocks of China. Third is the placer type, represented by the Çanaklı (Burdur) deposit which is enriched in U, Th and HREE and heavy minerals such as; magnetite, zircon and rutile and has an average grade of about 0.08% TREE. The fourth potential source of REE is phosphorites. These rocks host the world’s largest resources elsewhere, however the Cretaceous Mazidag deposits in Turkey are very low grade (40ppm TREE) and clearly uneconomic. Consideration of the environmental and health issues associated with exploitation and processing of REE has identified the more favorable outcomes associated with exploitation of the ion adsorption type of deposits and justification for further evaluation of the resources and processing technologies that would enable exploitation of REE-enriched bauxites in the Bolkardağı region. https://doi.org/10.19111/bulletinofmre.471205

This study was made for investigating the relationship between iodine and hydrocarbon accumulations and to determine iodine contents of formation waters in the Southeastern Anatolia basin oilfields where have been produced almost all of the Turkey oils (more than 95%). Formation water samples have taken from 234 production wells in 49 oilfields which have different geological structures where oil and gas production has performed by the Turkish Petroleum Company (TPAO). Also, the drilling mud samples from EBY-17 oilwell in Elbeyli (Adıyaman) field has collected, and their iodine analyses were carried out. Although the fields in the Southeastern Anatolia basin are old and some fields the secondary production methods are used, the high relationship between the oil and gas deposits and iodine were proved. As well as in other oil and gas fields in the world, not all reservoir waters in the Southeastern Anatolia basin are saline. However, all of them are rich in iodine. Therefore, the iodine-rich waters are a direct indicator for oil and gas producible reservoirs (containing mature hydrocarbon). Reservoir-targeted iodine geology and hydrogeology methods have simple sampling process, and laboratory analyses can result at a short time. The results are low cost, reliable and consistent. In the case when these data are utilized with other geological and geophysical methods, it is determined will be a practical and useful tool to reduce the hydrocarbon exploration risk to a minimum and to discover new deposits suitable for commercial production. https://doi.org/10.19111/bulletinofmre.501519  

Each mineralization style is characterized by typical signature associations between elements due to elemental interactions, therefore the coherence and closure effects problem must be overcome in geochemical processing. The coherence indicates the ratios between two components (rows or columns) remains the same whether they are considered in a subcomposition or in the full composition. The log-ratio transformation (LRT) has recognized as a standard procedure to support subcompositional coherence. The log-transformed data is applicable for geochemical data to unveil such associations, prior to applying the multivariate analysis like correspondence analysis (CA) and principal component analysis (PCA). At the present study, subcompositional coherence is overcome by inverse iso-metric log-ratio transformation for geochemical compositional data at two polymetallic and porphyry deposits. Based on Ilr-transformed data, Ag, Au, As, Pb, Te, Mo and rather S, W, Cu are enriched as polymetallic elements at Glojeh, while Au-Cu-(Mo) compositions indicate a porphyry deposit occurred in Dalli deposit. The ability to handle zero values in the data matrix and determining an elemental eccentricity from the center of each axis based on Euclidean distances are the advantages of CA method, with compression to LRT. Whereas, loading factors which spread in every direction and providing subcompositional coherence are the competitive advantages of PCA based on LRT, for both case studies. Results with these techniques show significant ability to draw an inference in such geochemical data, and in improving the performance of multivariate techniques using LRT. https://doi.org/10.19111/bulletinofmre.456958  

The toxicity risks of being over exposed to ionizing radiation in the environments are of great concern to environmental and health scientists. The distribution of radioactivity concentrations of thorium, uranium and potassium were studied in randomly selected soil samples from ten (10) farm locations in Odo Oba, southwestern Nigeria in order to determine the radiological risks of farmers’ exposure to radionuclides. The mean estimation of thorium and potassium are greater than the global average by factors of 1,5 and 2,7, while that of uranium fall below the global average. The estimation of radioactivity ratios showed a depletion of uranium and enrichment of thorium in the study area. Further analysis on the radioelements (that is, thorium, uranium and potassium) showed that 83% of the estimated radiological risks are above the global average. The multivariate analyses involving Pearson’s correlation, Factor Analysis, Hierarchical Cluster Analysis were also used to explain the correlations among the data sets. It was affirmed from the multivariate analysis that the radiological hazards occur as a result of contributions from the three naturally occurring radionuclides. The values obtained in this study revealed that the sampled locations are contaminated zones for farmers. https://doi.org/10.19111/bulletinofmre.495321  

In this study, simulation aided design of grinding circuit for a gold mine in Iran is presented. The main parameters for the design of the grinding circuit are the ore specifications and the considered operating conditions. Ore specifications were characterized by grinding tests, which included the Drop – weigh test (A, b), the abrasion test (ta) and the Bond Work Index test (Wi). For this study, the operating conditions for the processing plant are the ability to process clayey minerals and the plant throughput and the d80 of the hydrocyclone overflow (leaching tank feed), which are 125 tons per hour and 45 μm, respectively. Simulation operations were performed using grinding parameters (A, b, ta, Wi), operating constraints (plant capacity, d80 of the hydrocyclone overflow and ability to work for clayey minerals), existing mathematical models for different types of crushers, mills and separators and JKSimMet software. By completing the simulation process, three different alternatives for the grinding circuit of the considered ore were predicted. These three alternatives have been compared and evaluated with each other in terms of specific energy consumption (kWh/t), sensitivity to operational variables and the ability to process clayey minerals. The optimal circuit must have the capability to process clayey minerals and must have the lowest specific energy consumption and the least sensitivity to operational variables. By considering all these factors, the Alternative 3 is selected and suggested for an efficient grinding circuit. https://doi.org/10.19111/bulletinofmre.501432  

When processing gravity data, the filters are used in space and frequency environments. The filters allow more selectable parameter estimations than raw data about the structure being examined. Filtering in a broad sense means monitoring the data under the constraints we want. While the filters allow some information to become more noticeable, they allow some information to be lost or become less noticeable from data. In this case, the losses in the data make the interpretation difficult and can cause errors. Derivative and phase filters provide quantitative information about the variation of data in different directions. The display of the change results in a positive or negative manner proportional to derivative sensitivity and phase sharpness, and this may be observed in this data. In the structural boundary analysis, since the sudden changes in the derivative cause oscillations, the boundaries become questionable. Limiting the data neighborhoods with a window by controlling the deviation without using derivative and the filters that allow boundary analysis non-derivative by floating this limitation are used to illuminate the boundary relationships. https://doi.org/10.19111/bulletinofmre.546153