Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey最新文献

{"title":"INVESTIGATION OF GEOLOGICAL, GEOCHEMICAL AND GEMOLOGICAL FEATURES OF DIASPOR FORMATIONS IN THE SOUTHWESTERN SIDE OF THE MENDERES MASSIF (AYDIN-MUĞLA)","authors":"Eyyüp Hikmet Kinaci, A. Öztürk","doi":"10.25288/tjb.1084167","DOIUrl":"https://doi.org/10.25288/tjb.1084167","url":null,"abstract":"With the increasing interest in gemstones, which have started to offer an important underground wealth for countries. Menderes Massive is one of the most widespread and most important areas of bauxite deposites in the Turkey. Gemstone quality diaspore crystals are formed only within these deposits. In this study, diaspore formations in the southwest wing of the Menderes Massive (Aydın - Muğla) were examined and their geological, geochemical and gemological properties/characteristics were investigated. Bauxite deposits in the study area are observed along the discordance between white crystallized limestone (lower) and gray-dun colored crystallized limestone (upper) contact. The deposits generally extend in NW - SE direction and the samples show massive, pisolotic, oolitic and leopard texture. Diaspore crystals of different lengths and colors are unique to our country, which starting from Bafa Lake and advancing towards Yatağan in the form of dashed arc. It has been extracted as a by-product as a result of diasporitic bauxite production in a single mine for many years and it is not thought to have an economic value. \u0000Diaspore formations in the study area are generally observed as lenticular, brecciated, cracked and pockets in crystallized limestones, bauxite and altered zones with calcite, muscovite and chloritoid minerals. Diaspores are generally observed in the form of sheet around Milas. Increased interest in diaspore crystal, especially in the last 30 years and this study will be important in terms of gaining the deserved value of diaspore crystal which is unique to our country. Since it is likely that new diaspore deposits will be found in the region, further studies are planned on this subject. The data to be obtained will be important in the determination of new diaspore deposits.","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47422905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GEOCHEMICAL PROPERTIES OF THE DÖLLÜK AND GÜMENEK (TOKAT-TURKEY) CHALCEDONIES","authors":"F. Arık, Abdurrahman Ruşen","doi":"10.25288/tjb.1078030","DOIUrl":"https://doi.org/10.25288/tjb.1078030","url":null,"abstract":"The study area is located within the borders of Tokat province, which is one of the richest provinces in Turkey in terms of gemstone diversity. The region has very high quality and various gemstone formations such as jasper, opal, chalcedony, agate, chrysoprase, which have both geological and commercial value. \u0000Metamorphic, magmatic, and sedimentary units from the Paleozoic to the present day crop out in the study area. While Paleozoic-Mesozoic Tokat metamorphics and Artova ophiolite mélange form the basement, the Almus formation, which is represented by Lower Miocene aged volcano-sedimentary rocks from the central parts of the area to the east, covers these units unconformably. Quaternary slope debris and alluviums in the Yeşilırmak basin are the youngest units in the region. \u0000The chalcedony formations are observed along an E-W trending almost vertically dipping fault zone passing through the north of Döllük and Korucak Villages within the metamorphic units of the Tokat Massif. The chalcedonies are in the cracks, fractures and cavities of the recrystallized limestones that exhibit a fractured and brecciated structure along a line of approximately 25 m in the direction perpendicular to this fault zone. \u0000In mineralogical, petrographic, and gemological studies, quartz, tridymite, cristobalite, calcite and dolomites were determined together with chalcedony. Chalcedonies have average 96.3% SiO2, 1.96 % Fe2O3, 0.56 % MgO, 1.02 % CaO, 780 ppm Cr2O3, 6.3 ppm Cu, 20 ppm Hg, 4.2 ppm Pb, 18 ppm Ni and 77 ppm Zn. Chalcedony formations are the last product of a hydrothermal system related to volcanic activities after the formation of the wall-rocks. The movement of chalcedony-generating solutions within the fault zone and their inclusions of carbonate wall rock and secondary calcite formations during chalcedony formations ensured that the CaO and MgO contents of the chalcedony were relatively high.","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46490825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EVALUATION OF GEOCHEMICAL PROPERTIES OF AGATES IN ALMUS (TOKAT) REGION","authors":"F. Arık, Erhan Turhal, Y. Özen","doi":"10.25288/tjb.1067344","DOIUrl":"https://doi.org/10.25288/tjb.1067344","url":null,"abstract":"The Upper Cretaceous Artova ophiolite complex, represented by metabasic and ultrabasic rocks, overlies the Paleozoic aged Tokat metamorphites, which form the basis of the study area, by the tectonic boundary. Haydaroğlu formation, which includes Middle Eocene aged volcanogenic units, cuts and covers the older units. Agates (agates) in the Almus region are found in the form of nodules in the volcanogenic sandstones of the Haydaroğlu formation along an approximately E-W trending fault. The Lower Miocene aged Almus formation, which consists of sedimentary rocks such as sandstone, conglomerate and marine limestone, also unconformably overlies all units. \u0000Almus region agates contain on average 93.4% SiO2, 3.59% Fe2O3, 0.03% MgO, 0.72% CaO, 793 ppm Cr2O3, 12 ppm Ni, 13.4 ppm Cu, 4.7 ppm Pb, 35.4 ppm Zn. The high Cr and Ni in agates are associated with the Artova ophiolite complex in the region. Cu, Pb and Zn are associated with the early stages of volcanism. The high Fe2O3 content in agates is associated with hematite and goethite, and they were transported into agates before SiO2 emplacement. The CaO in the agate is the product of the last phase of the solution forming the agate, and MgO is associated with the presence of dolomite. \u0000Evaluation of the results of geochemical analysis shows that SiO2, which is the main component due to the hydrothermal activities that occurred after the rock formation of the Haydaroğlu formation, unlike the volcanic bedrocks of the agates according to the main oxides, trace and rare earth elements, was emplaced epigenetically as a result of the circulations in the volcanogenic sandstones.","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49558174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The First Petrographic Textural Data of Sferulitic Rhyolites Observed in the west of İdrisyayla (Kırka-Eskişehir)","authors":"Yeşim Yücel Öztürk, C. Akal","doi":"10.25288/tjb.1084686","DOIUrl":"https://doi.org/10.25288/tjb.1084686","url":null,"abstract":"Spherulitic structures are classically defined as concentrically zoned crystal clusters that form in igneous systems (especially in alkaline igneous rocks), and usually occur as different mineral layers or shells. \u0000The volcano-sedimentary series observed in the Kırka region, south of Eskişehir, within the Kırka-Afyon-Isparta Volcanic Province, Western Anatolia, consists predominantly of Lower Miocene volcanic and pyroclastic sequences with rhyodacitic-rhyolitic in composition, lacustrine limestones, borate-bearing claystones, tuff, stromatolitic limestones and basalts. The formation mechanisms of the spherulitic structures observed in the marginal zone of the sub-alkaline rhyolitic lava dome outcropping within the Neogene series in the west of İdrisyayla in Kırka (Eskişehir) region were described for the first time with this study. The rhyolites are grayish light brown in color, have hypocrystalline hyalopilitic-holohyaline texture and present spherical structures defined as spherulites. These rocks present a completely flowing structure and are composed of volcanic glass containing rarely euhedral plagioclase and quartz microcrystals, The spherical structures observed on the surface of the rhyolites are up to 10-15 cm in size. The spherulites, which are almost round in shape, appear as concentric rings within the lava flow bands. The flow band texture of the volcanic glass phase presents continuity in the inner texture of the spherulitic structures. \u0000This study suggests that the sferulitic structures in the İdrisyayla (Kırka-Eskişehir) region were formed by the devitrification mechanism as a result of high temperature and rapid cooling. The petro-mineralogical features of the spherulitic rhyolites show that during the early magmatic stage, the oversaturated liquid crystallized in silica-rich fluid phases of relatively different densities, and radial quartz-feldspar crystal growths from a center, caused the formation of the spherulitic structure. It is also suggested that the lithophysae-like structures formed by the crystal growths representing the solid phase in the axial cavities due to the locally folding of the flow bands and the following radial mineral growths representing the liquid phase, were also changed the laminated texture in the marginal phase of the rhyolite.","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47206425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some Mineralogical and Gemological Properties of Silicified Wood Species in Western Anatolia","authors":"Burcu Üner, Sabah YILMAZ ŞAHİN, Ü. Akkemik","doi":"10.25288/tjb.1088732","DOIUrl":"https://doi.org/10.25288/tjb.1088732","url":null,"abstract":"The silicified wood samples identified in Western Anatolia are located in the Late Miocene-Pliocene aged Çokköy Formation in Tavşanlı (Kütahya) and its surroundings, in Osmancalı (Manisa) and its vicinity in the Early (?)-Middle Miocene aged Foça Tuff and in Banaz (Uşak) around in the Middle-Late Miocene aged Yeniköy Formation within the terrestrial sediments. The formation of woods petrified by the silicification mechanism is associated with the sedimentation of clastic sediments formed simultaneously with the Neogene period volcanic activities in the region. In the mineralogical-petrographic examinations on three oriented thin sections, including transverse, radial and tangential, chalcedony polymorphs of silica and less quartz and opal were detected in silicified wood samples. Mineralogical interpretations were also supported by X-Ray Diffractometry (XRD) analysis. As a result of paleobotanical definitions made with thin sections in the botanical microscope; Taxodioxylon Hartig 1848 (Swamp cypress), Pinuxylon Gothan 1906 (Pine), Pterocaroxylon Müll.-Stoll et Mädel 1960 (Walnut), Quercoxylon (Kräusel 1939) Gros 1988 (evergreen oak), Glyptostroboxylon Conwentz 1884 (Swamp cypress) fossil wood species were identified. According to these findings, a warmer and more humid climate prevails than today, cypress forests on the edges of swamps and streams, and pine and evergreen oak forests on the slopes were determined. Within the scope of gemological examinations of silicified wood samples, samples which are rich in color/pattern were selected, polished by giving cabochon forms, then mounted with silver. A small amount of facet cutting studies were carried out from unpatterned and monochromatic samples. Silicified wood samples, which have high values in terms of hardness, exhibit an unstable character due to the weak zones they contain and do not show the desired performance in terms of pattern/color.","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47902860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Moralli Deresi Sisteminin Kuvaterner Yaşlı Tortullarının Tane Boyu Dağılımı ve Depolanma Ortamları (Tuşba, Van, Türkiye)","authors":"Gülsade Şen, Türker Yakupoğlu","doi":"10.25288/tjb.1041321","DOIUrl":"https://doi.org/10.25288/tjb.1041321","url":null,"abstract":"","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47079457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Çal Kanyonu ve Çevresinin (Denizli, GB Anadolu) Jeolojik-Jeomorfolojik Özellikleri ve Jeoturizm Potansiyeli","authors":"Arzu Gül, M. Özkul","doi":"10.25288/tjb.935447","DOIUrl":"https://doi.org/10.25288/tjb.935447","url":null,"abstract":"","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45143660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Göl Çökellerinde Polen Analizlerine Dayalı Paleoiklim Rökonstriksüyonu İçin Yerbilimci Bir Yaklaşım; Sorunlar ve Çözümler","authors":"Güldem Kamar","doi":"10.25288/tjb.1067964","DOIUrl":"https://doi.org/10.25288/tjb.1067964","url":null,"abstract":"","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46250900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geophysical Studies to Identify Iron Mineralization Anomalies Using Terrestrial Magnetometry in The ChakChak Area","authors":"A. Aali, A. Shirazi, Adel Shirazy, Shayan Khakmardan","doi":"10.25288/tjb.1035354","DOIUrl":"https://doi.org/10.25288/tjb.1035354","url":null,"abstract":"","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41848114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Termination of Little Ice Age in Northeastern Anatolia, A multi-proxy paleolimnology study of undisturbed sediments, Lake Aygır (Kars, NE Anatolia)","authors":"A. E. Erginal, N. Yakupoğlu, Çağlar Çakır, Abdullah Akbas, Serkan Kükrer","doi":"10.25288/tjb.1033421","DOIUrl":"https://doi.org/10.25288/tjb.1033421","url":null,"abstract":"","PeriodicalId":42517,"journal":{"name":"Turkiye Jeoloji Bulteni-Geological Bulletin of Turkey","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48281112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}