Bulletin of the Mineral Research and Exploration (BMRE)
Not a member yet
1932 research outputs found
Sort by
Active tectonics of Gülpınar-Tuzla area (Biga Peninsula, NW Turkey): the source of 6 February-24 March 2017 earthquake cluster
No full textThe variation in the motion sense of Anatolian platelet in Aegean Sea resulted in a strike-slip tectonic regime and related neotectonic domain, the central to northern Aegean neotectonic province, which also includes both western Marmara Sea and Biga Peninsula. Our study focuses mostly on the Gülpınar-Tuzla earthquake area located at the southwestern tip of Biga Peninsula,which is controlled by the southern major strand of the North Anatolian Fault System (NAFS). The strand consists of two sections, the onshore Biga and offshore Babakale-Skyros sections. Both sections are seismically very active. The Gülpınar-Tuzla earthquake area is composed of the Paleozoic metamorphic rocks, the Oligo-Miocene granitoid pluton, Lower-Middle Miocene calcalkalic volcanic rocks and the Upper Miocene-Pliocene sedimentary sequence. All of these rocks, which formed and deformed (folded to tilted) in palaeotectonic period, are overlain with an angular unconformity by the Quaternary neotectonic basin fill, that is nearly flat-lying except for the faulted basin margins. Both the onshore and offshore sections of the southern strand are linked to each other in terms of the structures characterizing the Babakale pull-apart basin and the Gülpınar-Tuzla earthquake area. The latter is shaped by the NE-trending Gülpınar (GFZ) and Yenice-Gönen Fault Zone (YGFZ), the ENE-trending Edremit fault zone (EFZ), the WNW-trending Tuzla Fault Zone (TFZ) and three strike-slip basins (Ayvacık, Behramkale and Tuzla basins) developed along them. Some segments of both the TFZ and GFZ were reactivated by the occurrences of seven moderate-to small-sized independent earthquakes and related aftershocks over 2760. Five of the independent earthquakes have an origin of oblique-slip normal faulting, while the rest two seismic events are strike-slip faulting in origin. Focal mechanism solution diagrams of these two groups of earthquakes reveal that the Gülpınar-Tuzla area is under the control of a strike-slip neotectonic regime, which commenced in Early Quaternary time owing to the major inversion in extensional palaeotectonic regime. This is also supported by the palaeostress analysis of slip-plane data measured on fault slickensides. The uniform slip rates on both the YGFZ and EFZ are 10.8 mm/yr and 7.3 mm/yr, respectively.
https://doi.org/10.19111/bulletinofmre.98492
Alien foraminifers of the northern and northeastern coastlines of Cyprus Island
No full textThe study area covers the northern coasts of Cyprus from the Güzelyurt Gulf to the Gazimağusa Gulf. This study was carried out in order to reveal the presence of the alien foraminifera, which are widely distributed in the Eastern Mediterranean particularly Amphistegina lobifera in the study area, and the effects of trace elements on faunal assemblages (foraminifera, ostracod and mollusc). The bottom sediment samples were taken from eighteen different points and depths, the faunal assemblages were examined, and the sediment distribution map of the studied area was made by ICP-MS analysis and geochemical evaluations. 30 genera and 48 species of foraminifera have been identified, of which 9 species belonging to 6 genera are the alien foraminifera. These are: Spiroloculina angulosa, S. antillarum, Hauerina diversa, Coscinospira hemprichii, Peneroplis pertusus, P. planatus, Amphisorus hemprichii, Sorites orbiculus and Amphistegina lobifera. Amphistegina lobifera was observed to be abnormally abundant in most of the samples. This foraminiferal assemblage of Red Sea origin constitutes a poor assemblage compared to the alien assemblages in Turkish Mediterranean coastal areas. It has been determined that the ostracod and mollusc genera and species found in the same samples belong to the typical Mediterranean and Aegean Sea community. https://doi.org/10.19111/bulletinofmre.83860
Clay mineralogy and paleoclimatic properties of the Neogene Deposits in Sinanpaşa Basin (Afyon-Western Anatolia)
No full textThe Sinanpaşa basin, one of the Neogene basins formed in the extensional tectonic regime in Western Anatolia, is located on the eastern margin of Western Anatolia basins containing different types of evaporites, lignite, uranium and clay minerals. Miocene sequence was initiated with alluvial fanfluvial units and followed by lacustrine sediments. River floodplains and lakeshore marshes locally contain economic coal levels. Since middle-late Miocene, the products of Afyon volcanism were deposited into a subaerial or a subaqueous environment alternating with lake sediments. Dominant clay minerals are illite and smectite within the sediments coexistence with the volcanics. These minerals were accompanied by chlorite, kaolinite, and zeolite in some samples. Feldspar, dolomite, thenardite, and gypsum are locally observed too. Sepiolite mineral enrichments are also noteworthy in shallow-coastal lacustrine environments where organic matter is abundant. Clay minerals are mostly detritic and developed due to the weathering of volcaniclastics and sedimentary rocks in temperate/humid climatic conditions. In particular, smectite and kaolinite minerals were formed in situ/authigenic under subaqueous conditions due to the acidic/basic character of tuffs. As a result, different clay mineral types have been developed due to the mineralogical composition of source rocks, climatic factors (humid/semi-humid, arid), paleotopography, depositional environment and diagenetic factors. https://doi.org/10.19111/bulletinofmre.70798
Upper Cretaceous-middle Eocene aged olistrostromal pelagic units in the Biga Peninsula (NW Anatolia); Balıkkaya formation
No full textBalıkkaya formation consists of olistostromal units with a burgundy coloured mudstone, siltstone and pelagic limestone matrix containing various sizes of UpperJurassic-Lower Cretaceous limestone (Bilecik Limestone) blocks and Triassic Karakaya Complex blocks, which crop out in the west, south and southwest of Biga Town in Biga Peninsula (NW Anatolia). The matrix of Balıkkaya formation, of which age and sedimentary environment are controversial, contains Late Cretaceous (Maastrichtian) Abathomphalus mayaroensis (Bolli), Abathomphalus sp., Rosita fornicata (Plummer), Globotruncanidae, early Paleocene (Danian) Morozovella pseudobulloides (Plummer), late Paleocene (Thanetian) Morozovella velascoensis (Bolli), early Eocene Acarinina pentacamarata (Subbotina), middle Eocene Turborotalia frontosa (Subbotina), Turborotalia cerroazulensis (Cole), Orbulinoides beckmanni (Saito), Hantkenina sp. pelagic foraminifera and Radiolariafossils representing the deep marine environment. These paleontological, lithological and sedimentological data obtained from Balıkkaya formation show that Balıkkaya formation developed in a deep marine environment under tectonic control starting from Late Cretaceous and ending in early-middle Eocene. This pelagic unit indicates the presence of a extensional tectonic regime on the Biga Peninsula and the fault activity along the southeastern edge of the Thrace Basin in the Late Cretaceous-Middle Eocene time interval.
https://doi.org/10.19111/bulletinofmre.71987
The relation of seismic velocity and attenuation pattern in the East Anatolian fault zone with earthquake occurrence: Example of January 24, 2020 Sivrice earthquake
No full textThe East Anatolian Fault Zone (EAFZ) is one the main tectonic elements of Turkey, which borders the Anatolian plate from the east. EAFZ, which is NE - SW direction, consists of many fault segments. In the historical and instrumental period, many damaging earthquakes occurred, the largest being 6.8 (Ms) as the 1971 Bingöl earthquake. The last magnitude 6.6 (Ml) (Mw=6.8) earthquake occurred on January 24, 2020 in Elazığ-Sivrice Hazar-Sincik segment of EAFZ. However, considering the historical and instrumental activity, it is seen that many fault segments are silent. In this study, the silent and active segments, and their seismic velocity (as % Vp and Vp) and attenuation pattern (as Q-1 p) are determined in order to determine the earthquake behavior of EAFZ in the near future. From the results obtained by using the data of the earthquakes that occurred from 2007 to the end of 2019, it was clearly determined that the velocity and attenuation increased on the Hazar-Sincik segment. It has been determined that Vp is 4.08-8.2 km/sec, Q-1 p is ± 0.005 and the frequency dependency varies between 0-1.08 along the zone. The variation of velocity and attenuation on the segments where the earthquake occurred and in the silent section were revealed.
https://doi.org/10.19111/bulletinofmre.82403
Systematics, biostratigraphy and paleoenvironmental investigation of early Ypresian Alveolina assemblages in the northern part of Isparta Angle (Keçiborlu, Isparta, SW Turkey)
No full textIsparta Büklümü’nün kuzey kesiminde (Keçiborlu, Isparta, GB Türkiye) yüzeyleyen Tanesiyen- erken İpresiyen (orta İlerdiyen) yaşlı Büyükkırtepe formasyonuna ait kireçtaşları zengin bir bentik foraminifer topluluğuna sahiptir. Formasyonun Alveolina türleri açısından yüksek çeşitlilik sunan İlerdiyen düzeyleri Alveolina (Glomalveolina) karsica, A.(G.) aff. karsica, A.(G.) lepidula, A.(G.) cf. subtilis, A. (Alveolina) aragonensis, A.(A.) cemali, A.(A.) corbarica, A.(A.) cf. coudurensis, A.(A.) decipiens, A.(A.) dedolia, A.(A.) ellipsoidalis, A.(A.) erki, A.(A.) guidonis, A.(A.) cf. ilerdensis, A.(A.) montanarii, A.(A.) moussoulensis, A.(A.) pasticillata, A.(A.) pisella, A.(A.) rotundata kazancii, A.(A.) trempina, A.(A.) varians ve A.(A.) vredenburgi gibi türlerle karakterize olur. Alveolina cinsine ait 30 farklı tür ve alt tür içeren topluluktan A.(A.) acari n.sp. ve A.(A.) ozbahcensis n.sp. yeni türleri ile A.(A.) avsari fusunae n.ssp. yeni alt türü ilk kez bu çalışmada tanımlanmıştır. Ayrıca birey sayılarının yetersiz olması nedeniyle adlandırılmamış olası yeni alttürler tanımlanarak önerilmiştir. Çalışma alanında bentik foraminifer zonlarından SBZ 3-SBZ 8 biyozonları aralığında tanımlanan Alveolina topluluğu, genel olarak Tetis Kuşağı’nın diğer bölgelerindeki eş yaşlı topluluklar ile benzer stratigrafik dağılımlar göstermesine karşın, bazı farklılıklar sunmaktadır. Elde edilen veriler, çalışma alanının Tanesiyen-erken İpresiyen (orta İlerdiyen) zaman aralığında lagün ortamından, normal tuzluluğa sahip düşük enerjili sığ denize kadar değişen bir ortam olduğunu göstermektedir. https://doi.org/10.19111/bulletinofmre.74094
Geology of the Yeşilyurt gold deposit: an example of low-angle normal fault related mineralization, Eastern Anatolia-Turkey
No full textYeşilyurt gold mineralization is located within the provincial borders of Malatya and Adıyaman in the East Anatolian Region. This mineralization is one of the gold deposits which correlated with low-angle normal/detachment fault. Low-angle normal fault associated with a tectonic setting which is potential extensional in Paleogene-Neogene (?) term. Marble-recrystallized limestone which belongs to the metamorphic core is the dominant rock (footwall) type in the bottom plate of the fault zone. There are deformed graphitic calc-schists (hanging wall) in the upper plate of the fault zone. The fault zone is characterized by fault gauge, cataclasite, and breccia. While the cataclasite, and breccia are the principal ore host, there is weaker mineralization in fault gauge. Alteration assemblages are: (1) silica replacements/veinlets and, (2) quartz-pyrite replacements / veinlets. High gold contents are closely related to silicification and quartz-pyrite alteration which damaged the primary textures. Small volume syn-tectonic magmatic rocks are simultaneous and typically monitored in the silicified areas which are border on the high-grade gold mineralization. Mineralization is a non-base metalliferous Au depositthat contains Au/Ag ~ 1.07, As (~0.27%), F (1.59%), and a trace amount of Sb. This deposit will lead to finding new gold deposits in Eastern Taurus Orogenic Belt. https://doi.org/10.19111/bulletinofmre.79772
The distribution of elements in the alteration of feldspatic minerals
No full textFeldspar (alkali feldspar and plagioclases) and in recent years feldspathoid minerals are used as raw materials in the ceramic-glass industries. The igneous rocks such as granite, syenite and foid syenite which mainly contain these minerals have the potential to be raw materials. Some inclusions within the feldspatic minerals affect extremely negatively the desired values for raw material. In this study, the effective processes in the alteration of feldspatic minerals within the Özvatan foid syenites, the effects of alteration minerals in the raw material were evaluated and the effects of the elements released by alteration on the environment were revealed. The foid syenites consist of nepheline, orthoclase, plagioclase, cancrinite, sodalite, amphibole, biotite, pyroxene, melanite with a rare amount of sphene, zircon, apatite and fluorite. The contents of the sericite and kaolinite, which are formed as a result of an alteration of these rocks, increase in direct proportion to alteration degree. As a result of the alteration index values, foid syenites samples show the low degreed decomposed property. According to the calculated mobility index (MI) from chemical analyses, there is a quantitative decrease in the major oxides such as SiO2, Al2O3, Na2O, K2O, CaO and Fe2O3 in the foid syenites. In accordance with the all data, Özvatan foid syenites have been exposed both weathering and hydrothermal alteration and the effect of hydrothermal alteration are observed more frequently in the altered rock. While the excess of diaclase structures within the rock provides ease of operation, on the other hand, it accelerated the weathering and alteration processes. https://doi.org/10.19111/bulletinofmre.90103
Determination of the origin and recharge process of water resources in Salda Lake Basin by using the environmental, tritium and radiocarbon isotopes (Burdur/Turkey)
No full textThe Salda Lake basin which is in the southwestern Turkey is an important water body in view of environmental values. We used stable isotopes (δD and δ18O), δ3H and 14C composition of the water samples to understand recharge process effective in the groundwater and lake water. Water samples were collected in dry and wet periods and the stable isotope (δD and δ18O) and radiogenic isotope (14C) analysis were made in the basin. The δ18O contents of groundwater and lake water ranged from -9,94‰ to 1,18‰ in dry period and from -10,24‰ to 0,30‰, in wet period. δD contents of groundwater and lake water varied from -67,42‰ to 1,20‰ and from -64,51‰ to -2,80‰, in dry and period wet respectively. The stable isotope data of samples indicate a meteoric origin for all samples. According to stable isotope data, groundwater samples seem to be recharged from higher elevations whereas the lake water is recharged from low elevations. The tritium (δ3H) content of the water samples ranges from 1.04 to 4.49 TU and from 1.91 to 4.18 TU in the dry period and wet period respectively. Long-term δ3H observations are required to determine whether these δ3H signals are associated with young recharge or with the groundwater with long residence time. In addition, the 14C activities of the samples vary between 90 pmc and 110 pmc for Salda Lake waters and 530 pmc and 5990 pmc for the groundwater.
https://doi.org/10.19111/bulletinofmre.60435
2D and 3D structural boundaries of the tectonic composition of the Anatolia and surrounding seas using by the gravity (Satellite Data): Eastern Mediterranean
No full textGravity data is processed and the problems of the earth are examined. The density of the data can be arranged to solve detail, semi-detail and regional problems. Here, the gravitational data obtained by processing the linearity of the 2D and 3D visuals in terms of plate size large wavelength structures are examined. 2D linearities determine important stress areas but they are affected at different rates with respect to the spatial distribution of source effect. Due to grid formation, these boundaries are affected at different rates from less dense and very dense structures. Different wavelengths in structure boundary analysis; derivative and phase elements and filters. Vertical change in 3D analysis can be made at the approach level with the analytical examination of 2D change. At this stage, the distribution of source effect and depth model structure parameters are calculated. When examining large wavelength structures, some of the buried structures appear due to cover removal. In search of solutions for tectonic structures that we may miss; The tectonic components that need to be confirmed in the Eastern Mediterranean have been tried to be elucidated in this study. 3D building solutions are important in this respect. https://doi.org//10.19111/bulletinofmre.64123