Pub Date : 2024-09-10DOI: 10.1016/j.chemer.2024.126181
Flávia Compassi da Costa, Brener Otávio Luiz Ribeiro, Lucas Pereira Leão, Paulo Augusto de Paiva-Silva, Ricardo Scholz
The state of Espírito Santo is located in Brazil southeastern and it is geologically inserted in the Eastern Brazilian Pegmatite Province in the Araçuaí Orogen. This province is one of the most important pegmatite provinces in the world, known mainly for the occurrence of gem-quality minerals and high grade lithium deposits. Although Espírito Santo has a geological framework with many granite intrusions similar to those hosting mineralized pegmatites in Minas Gerais, it hasn't been acknowledged as a potential pegmatitic area. There are reports of mineralization of beryl (aquamarine), topaz, amethyst, and chrysoberyl in the state's mineral history. I this research we use regional stream sediment geochemical data of the Espirito Santo State, to create prospective geochemical maps to map gemological pegmatites. To do so, primary descriptive statistical analyses as well as Pearson and Spearman correlations and Principal Component Analysis (PCA) were used to select elements associated with pegmatites. The geochemical prospectivity mapping was carried out by supervised and unsupervised approaches. The supervised method was based on integration of the elements by C-A fractal models, used to define the geochemical thresholds, and fuzzy logic methodology to integrate weighted geochemical maps. The unsupervised approach, however, was based on interpolation of the representative principal component scores. All models were validated using the Prediction Area plot (P-A plot). The results of our research showed that unsupervised methodology overperformed the other weighted supervised models, with a prediction rate of 78.14 % and prospectivity of 0.87. The final results also show a pegmatite prospectivity map for the Espirito Santo state, that indicates a great exploration potential for gemological minerals.)
{"title":"The influence of supervised and unsupervised methods in the analysis of low density stream sediments in the regional prospecting of pegmatites in the state of Espírito Santo, Araçuaí Orogen - Eastern Pegmatite Province of Brazil","authors":"Flávia Compassi da Costa, Brener Otávio Luiz Ribeiro, Lucas Pereira Leão, Paulo Augusto de Paiva-Silva, Ricardo Scholz","doi":"10.1016/j.chemer.2024.126181","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126181","url":null,"abstract":"The state of Espírito Santo is located in Brazil southeastern and it is geologically inserted in the Eastern Brazilian Pegmatite Province in the Araçuaí Orogen. This province is one of the most important pegmatite provinces in the world, known mainly for the occurrence of gem-quality minerals and high grade lithium deposits. Although Espírito Santo has a geological framework with many granite intrusions similar to those hosting mineralized pegmatites in Minas Gerais, it hasn't been acknowledged as a potential pegmatitic area. There are reports of mineralization of beryl (aquamarine), topaz, amethyst, and chrysoberyl in the state's mineral history. I this research we use regional stream sediment geochemical data of the Espirito Santo State, to create prospective geochemical maps to map gemological pegmatites. To do so, primary descriptive statistical analyses as well as Pearson and Spearman correlations and Principal Component Analysis (PCA) were used to select elements associated with pegmatites. The geochemical prospectivity mapping was carried out by supervised and unsupervised approaches. The supervised method was based on integration of the elements by C-A fractal models, used to define the geochemical thresholds, and fuzzy logic methodology to integrate weighted geochemical maps. The unsupervised approach, however, was based on interpolation of the representative principal component scores. All models were validated using the Prediction Area plot (P-A plot). The results of our research showed that unsupervised methodology overperformed the other weighted supervised models, with a prediction rate of 78.14 % and prospectivity of 0.87. The final results also show a pegmatite prospectivity map for the Espirito Santo state, that indicates a great exploration potential for gemological minerals.)","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255597","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}
Pub Date : 2024-09-05DOI: 10.1016/j.chemer.2024.126177
Fatma Hoş Çebi
In this study, saturated, aromatic biomarker distributions and organic geochemical characteristics and depositional environments of Middle Miocene aged coals in Ekizköy (Muğla-Milas) region were investigated. The average TOC, HI and OI values are 46.24 %, 153 mg HC/gTOC and 77 mg CO/gTOC, respectively. Pr/Ph ratio is 0.9 and Pr/C and Ph/C are 0.2 and 0.3. Considering the paleoclimate data (TOC, CPI, ACL, P, P, Q, Q and Q), it is likely that the climate was moderately humid and hot for the period represented by sample M-4 and relatively more humid and temperate for the period represented by sample M-8. High C(C + C) MA steroid ratio indicates that Ekizköy coals are composed of terrestrial OM (Organic Matter). 20S/(20R + 20S) (for C), 22S/(22R + 22S) homohopane (for C), ββ/(αα + ββ) sterane, moretane/hopane ratios that show the maturity of OM are indicative of immature OM. CTA/(CMA + CTA) steroid and MA(I)/MA(I + II), TA(I)/TA(I + II), MDR, MPI, MPR ratios obtained from aromatic biomarkers are low and show an immature character. Since coals contain Type III kerogen and immature organic matter, they can only generate gas under appropriate temperature and pressure. Saturated and aromatic biomarker data in Ekizköy coals show that they precipitate in a lacustrine environment dominated by suboxic conditions.
本研究调查了埃基兹科伊（穆拉-米拉斯）地区中新世时期煤炭的饱和度、芳香族生物标志物分布和有机地球化学特征及沉积环境。平均 TOC、HI 和 OI 值分别为 46.24%、153 毫克 HC/gTOC 和 77 毫克 CO/gTOC。Pr/Ph 比率为 0.9，Pr/C 和 Ph/C 分别为 0.2 和 0.3。考虑到古气候数据（TOC、CPI、ACL、P、P、Q、Q 和 Q），M-4 样本所代表的时期可能是中度潮湿和炎热的气候，而 M-8 样本所代表的时期则是相对更加潮湿和温带的气候。高 C(C + C) MA 类固醇比率表明埃基兹柯伊煤炭由陆地 OM（有机物质）组成。20S/(20R + 20S)（代表 C）、22S/(22R + 22S)homohopane（代表 C）、β/(αα + ββ)甾烷、甲烷烃/蒎烷比率显示 OM 的成熟度，表明 OM 尚不成熟。从芳香生物标记物中获得的 CTA/(CMA + CTA) 类固醇和 MA(I)/MA(I + II)、TA(I)/TA(I + II)、MDR、MPI、MPR 比率较低，显示出不成熟的特征。由于煤炭中含有 III 型角质和不成熟的有机物，它们只能在适当的温度和压力下产生气体。Ekizköy 煤中的饱和及芳香生物标志物数据表明，它们是在亚氧条件为主的湖沼环境中沉淀的。
{"title":"Paleoclimate and paleodepositional condition of Ekizköy (Muğla-Milas) Middle Miocene coals: Implications from biomarker data","authors":"Fatma Hoş Çebi","doi":"10.1016/j.chemer.2024.126177","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126177","url":null,"abstract":"In this study, saturated, aromatic biomarker distributions and organic geochemical characteristics and depositional environments of Middle Miocene aged coals in Ekizköy (Muğla-Milas) region were investigated. The average TOC, HI and OI values are 46.24 %, 153 mg HC/gTOC and 77 mg CO/gTOC, respectively. Pr/Ph ratio is 0.9 and Pr/C and Ph/C are 0.2 and 0.3. Considering the paleoclimate data (TOC, CPI, ACL, P, P, Q, Q and Q), it is likely that the climate was moderately humid and hot for the period represented by sample M-4 and relatively more humid and temperate for the period represented by sample M-8. High C(C + C) MA steroid ratio indicates that Ekizköy coals are composed of terrestrial OM (Organic Matter). 20S/(20R + 20S) (for C), 22S/(22R + 22S) homohopane (for C), ββ/(αα + ββ) sterane, moretane/hopane ratios that show the maturity of OM are indicative of immature OM. CTA/(CMA + CTA) steroid and MA(I)/MA(I + II), TA(I)/TA(I + II), MDR, MPI, MPR ratios obtained from aromatic biomarkers are low and show an immature character. Since coals contain Type III kerogen and immature organic matter, they can only generate gas under appropriate temperature and pressure. Saturated and aromatic biomarker data in Ekizköy coals show that they precipitate in a lacustrine environment dominated by suboxic conditions.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255596","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}
The paper presents novel geochemical and geochronological data from granites in Khammam, Eastern Dharwar Craton (EDC), India. The studied granites contain major mineral phases like quartz, alkali-feldspar, plagioclase, biotite, and muscovite in decreasing order of abundance. The accessory phases are epidote, titanite, and zircon. The samples comprise 70 ‐–77 wt% SiO and 12–15 wt% AlO. The KO and NaO concentrations range from 2.57 to 5.65 wt% and 1.17 to 2.69 wt%, respectively. They are enriched in Rb, Th, and Pb and depleted in Nb, Ta, and Ti. On a chondrite-normalized plot, the samples exhibit a rightward trend with a negative Eu anomaly. Zircon saturation in silicate melts yields a temperature (T) of 859 ‐ 978 °C. The microstructure and U - Pb isotopic analysis of zircon grains ( = 79) reveals the presence of magmatic and polymetamorphic grains with Pb/Pb age clusters at 1844 Ma (number of analyses, = 7) - 1858 Ma ( = 8), 1737 Ma ( = 5) -1768 Ma ( = 4), 1619 Ma (n = 7) - 1634 Ma ( = 6), and 1554 Ma (n = 5), respectively. The magmatic zircons exhibit ε(Hf) values between 3 and 18.9 with a two-stage model age of 2.03 Ga. In contrast, the metamorphic zircons exhibit ε(Hf) values between −5.6 and 18, yielding a two-stage model age of 1.97 Ga. The geochemical and geochronological studies indicate that the rocks are A-type granite emplaced during the accretion of the eastern block of the North China Craton (NCC) and EDC between 1844 Ma and 1858 Ma. The zircons from 1737–1768 Ma and 1620 Ma show the time of metamorphic growth during Antarctica-Nellore Schist Belt (EDC) accretion. Finally, the U-Pb zircon ages from 1554 Ma represent Nuna's final amalgamation. The results of this study posit an association between EDC and NCC during Nuna assembly.
{"title":"Were South India and North China Craton attached during the Paleoproterozoic (Orosirian) Nuna Assembly? Novel geochemical and isotopic investigations of A2-type granites from the Khammam Schist Belt, Eastern Dharwar Craton, India","authors":"Ab Majeed Ganaie, Kausik Satpathi, Keewook Yi, Jeong Youn-Joong, Pritam Nasipuri","doi":"10.1016/j.chemer.2024.126178","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126178","url":null,"abstract":"The paper presents novel geochemical and geochronological data from granites in Khammam, Eastern Dharwar Craton (EDC), India. The studied granites contain major mineral phases like quartz, alkali-feldspar, plagioclase, biotite, and muscovite in decreasing order of abundance. The accessory phases are epidote, titanite, and zircon. The samples comprise 70 ‐–77 wt% SiO and 12–15 wt% AlO. The KO and NaO concentrations range from 2.57 to 5.65 wt% and 1.17 to 2.69 wt%, respectively. They are enriched in Rb, Th, and Pb and depleted in Nb, Ta, and Ti. On a chondrite-normalized plot, the samples exhibit a rightward trend with a negative Eu anomaly. Zircon saturation in silicate melts yields a temperature (T) of 859 ‐ 978 °C. The microstructure and U - Pb isotopic analysis of zircon grains ( = 79) reveals the presence of magmatic and polymetamorphic grains with Pb/Pb age clusters at 1844 Ma (number of analyses, = 7) - 1858 Ma ( = 8), 1737 Ma ( = 5) -1768 Ma ( = 4), 1619 Ma (n = 7) - 1634 Ma ( = 6), and 1554 Ma (n = 5), respectively. The magmatic zircons exhibit ε(Hf) values between 3 and 18.9 with a two-stage model age of 2.03 Ga. In contrast, the metamorphic zircons exhibit ε(Hf) values between −5.6 and 18, yielding a two-stage model age of 1.97 Ga. The geochemical and geochronological studies indicate that the rocks are A-type granite emplaced during the accretion of the eastern block of the North China Craton (NCC) and EDC between 1844 Ma and 1858 Ma. The zircons from 1737–1768 Ma and 1620 Ma show the time of metamorphic growth during Antarctica-Nellore Schist Belt (EDC) accretion. Finally, the U-Pb zircon ages from 1554 Ma represent Nuna's final amalgamation. The results of this study posit an association between EDC and NCC during Nuna assembly.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255626","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}
Pub Date : 2024-08-28DOI: 10.1016/j.chemer.2024.126180
Juexuan Huang, Zhankun Liu, Hao Deng
Hydrothermal mineral systems are formed by the transport of metals from large source areas through convective fluid flow, subsequent leading to deposition of these metals at specific sites. The fluid pathways are crucial for connecting mineral sources with favorable zones of mineral deposition. However, due to the complexity of fluid flow and limitations in sampling cost, assay cost, and expert experience, inferring fluid pathways poses a significant challenge. In this paper, we leverage the continuous and extensive characteristics of exploration data to identify fluid pathways in hydrothermal deposits, uncovering the hidden patterns from their mineralization footprints and favorable structural features within the data. By modeling the fluid flow as a Markov process, we tailor a hidden Markov model (HMM) to identify fluid pathways using observations of mineralization and structural features. Specifically, we identify the latent geometry of fluid pathways by maximizing their posterior probability as represented by the HMM. We then represent the identified fluid pathways as two quantitative and mappable exploration criteria—trajectory length and pathway flux—which serve as predictor variables in 3D mineral prospectivity mapping. Our method is applied to the Xiadian orogenic gold deposit in the Jiaodong Peninsula, China. The results suggest that the formation of Xiadian deposit is attributed to a series of fluid trajectories originating from two injection points. By using the exploration criteria derived from the identified fluid pathways, we significantly enhance the accuracy and efficacy of mineral prospectivity mapping, demonstrating the proposed HMM as an effective artificial intelligence tool for mineral exploration targeting.
{"title":"Identifying fluid pathways in hydrothermal deposits using hidden Markov models: Representation of fluid flow as exploration criteria","authors":"Juexuan Huang, Zhankun Liu, Hao Deng","doi":"10.1016/j.chemer.2024.126180","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126180","url":null,"abstract":"Hydrothermal mineral systems are formed by the transport of metals from large source areas through convective fluid flow, subsequent leading to deposition of these metals at specific sites. The fluid pathways are crucial for connecting mineral sources with favorable zones of mineral deposition. However, due to the complexity of fluid flow and limitations in sampling cost, assay cost, and expert experience, inferring fluid pathways poses a significant challenge. In this paper, we leverage the continuous and extensive characteristics of exploration data to identify fluid pathways in hydrothermal deposits, uncovering the hidden patterns from their mineralization footprints and favorable structural features within the data. By modeling the fluid flow as a Markov process, we tailor a hidden Markov model (HMM) to identify fluid pathways using observations of mineralization and structural features. Specifically, we identify the latent geometry of fluid pathways by maximizing their posterior probability as represented by the HMM. We then represent the identified fluid pathways as two quantitative and mappable exploration criteria—trajectory length and pathway flux—which serve as predictor variables in 3D mineral prospectivity mapping. Our method is applied to the Xiadian orogenic gold deposit in the Jiaodong Peninsula, China. The results suggest that the formation of Xiadian deposit is attributed to a series of fluid trajectories originating from two injection points. By using the exploration criteria derived from the identified fluid pathways, we significantly enhance the accuracy and efficacy of mineral prospectivity mapping, demonstrating the proposed HMM as an effective artificial intelligence tool for mineral exploration targeting.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187182","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}
Pub Date : 2024-08-23DOI: 10.1016/j.chemer.2024.126176
Sigma Dwivedy
{"title":"Petrogenetic implications, geochemistry and tectonic framework of albitite hosted magnetite in North Delhi Fold Belt: Application of geochemistry and apatite chemistry","authors":"Sigma Dwivedy","doi":"10.1016/j.chemer.2024.126176","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126176","url":null,"abstract":"","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255627","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}
Pub Date : 2024-08-15DOI: 10.1016/j.chemer.2024.126172
Ersin Kaygısız, Namık Aysal, Kıymet Deniz Yağcıoğlu
The Strandja Massif is one of the important metamorphic Massifs of Türkiye. The Strandja Massif consists of metasedimentary, and metamagmatic rocks such as migmatite, ortho- and paragneiss, metagranite, garnet-mica-schist, calcschist and marbles. For the first time, mineral chemistry analyzes of garnet-mica schists were performed to better understand the degree of metamorphism, and possible P-T conditions were defined in the north-northwest of the Strandja Massif. Based on almandine garnet and Fe-biotite mineral chemistry, garnet bearing mica-schist are affected by lower amphibolite facies metamorphism under 6.1 kbar pressure and approximately 547 °C. Moreover, detrital zircon UPb dating was performed on 107 points to describe the maximum depositional age of this garnet-mica schist. The youngest zircon Pb/U age obtained as 198 ± 17 Ma (98 % concordant, Th/U = 0.74) and the oldest Pb/U age yielded as 1896.8 ± 33.4 Ma (100.12 % compatible, Th/U = 0.63). Additionally, a zircon UPb concordia protolith age of 302.33 ± 1.79 Ma was obtained from orthogneisses. In-situ rutile-in garnet UPb dating shows that garnet-mica schists underwent metamorphism at 119 ± 49 Ma. P-T conditions and age of metamorphism show that these rocks effected by the lower amphibolite facies metamorphism during late Jurassic – early Cretaceous period.
{"title":"Detrital zircon and rutile U–Pb dating of garnet-mica schist in the Istranca (Strandja) Massif (NW Türkiye): Mineral chemistry and metamorphic conditions","authors":"Ersin Kaygısız, Namık Aysal, Kıymet Deniz Yağcıoğlu","doi":"10.1016/j.chemer.2024.126172","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126172","url":null,"abstract":"The Strandja Massif is one of the important metamorphic Massifs of Türkiye. The Strandja Massif consists of metasedimentary, and metamagmatic rocks such as migmatite, ortho- and paragneiss, metagranite, garnet-mica-schist, calcschist and marbles. For the first time, mineral chemistry analyzes of garnet-mica schists were performed to better understand the degree of metamorphism, and possible P-T conditions were defined in the north-northwest of the Strandja Massif. Based on almandine garnet and Fe-biotite mineral chemistry, garnet bearing mica-schist are affected by lower amphibolite facies metamorphism under 6.1 kbar pressure and approximately 547 °C. Moreover, detrital zircon UPb dating was performed on 107 points to describe the maximum depositional age of this garnet-mica schist. The youngest zircon Pb/U age obtained as 198 ± 17 Ma (98 % concordant, Th/U = 0.74) and the oldest Pb/U age yielded as 1896.8 ± 33.4 Ma (100.12 % compatible, Th/U = 0.63). Additionally, a zircon UPb concordia protolith age of 302.33 ± 1.79 Ma was obtained from orthogneisses. In-situ rutile-in garnet UPb dating shows that garnet-mica schists underwent metamorphism at 119 ± 49 Ma. P-T conditions and age of metamorphism show that these rocks effected by the lower amphibolite facies metamorphism during late Jurassic – early Cretaceous period.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255628","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}
Pub Date : 2024-08-08DOI: 10.1016/j.chemer.2024.126170
Hüseyin Kocatürk, Mustafa Kumral, Robert A. Creaser, S. Andrew DuFrane, Ali Tuğcan Ünlüer, Hüseyin Sendir, Zeynep Döner, Mustafa Kaya, Şenel Özdamar, Amr Abdelnasser
Late Paleocene to Middle-Eocene magmatism provides critical insights into the reconstruction of the Cenozoic geodynamic evolution of NW Anatolia. In this study, we mapped individual petrographic facies from the Eocene Uludağ Plutons (Topuk and Tepeldağ) and present zircon U-Pb geochronology, Sr-Nd isotope data, and comprehensive geochemical analyses for the entire plutons. We examined the Delice tonalite-granodiorite (D4) and Delice alkali-feldspar granite (D8) from the Topuk Pluton, as well as the Southern Tepeldağ quartz-monzodiorite (ST1) from the Tepeldağ Pluton. U-Pb zircon ages were 54.56 ± 0.21 Ma for ST1, 47.35 ± 0.21 Ma for D4, and 45.90 ± 0.29 Ma for D8. Initial Sr/Sr and Nd/Nd values were calculated, showing 0.706693 and 0.512428 for ST1, 0.707309 and 0.512452 for D4, and 0.705896 and 0.512448 for D8, respectively. The new zircon U-Pb ages for these facies cover nearly the entire interval from 54 to 45 Ma, enabling a comparison of magma evolution with the Late Paleocene to Middle-Eocene (58–45 Ma) magmatism.
{"title":"Magma nature and tectono-magmatic context of the Eocene Uludağ granitoids (NW-Türkiye): Insights into the Cenozoic geodynamics of the Tethyan Orogenic Belt","authors":"Hüseyin Kocatürk, Mustafa Kumral, Robert A. Creaser, S. Andrew DuFrane, Ali Tuğcan Ünlüer, Hüseyin Sendir, Zeynep Döner, Mustafa Kaya, Şenel Özdamar, Amr Abdelnasser","doi":"10.1016/j.chemer.2024.126170","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126170","url":null,"abstract":"Late Paleocene to Middle-Eocene magmatism provides critical insights into the reconstruction of the Cenozoic geodynamic evolution of NW Anatolia. In this study, we mapped individual petrographic facies from the Eocene Uludağ Plutons (Topuk and Tepeldağ) and present zircon U-Pb geochronology, Sr-Nd isotope data, and comprehensive geochemical analyses for the entire plutons. We examined the Delice tonalite-granodiorite (D4) and Delice alkali-feldspar granite (D8) from the Topuk Pluton, as well as the Southern Tepeldağ quartz-monzodiorite (ST1) from the Tepeldağ Pluton. U-Pb zircon ages were 54.56 ± 0.21 Ma for ST1, 47.35 ± 0.21 Ma for D4, and 45.90 ± 0.29 Ma for D8. Initial Sr/Sr and Nd/Nd values were calculated, showing 0.706693 and 0.512428 for ST1, 0.707309 and 0.512452 for D4, and 0.705896 and 0.512448 for D8, respectively. The new zircon U-Pb ages for these facies cover nearly the entire interval from 54 to 45 Ma, enabling a comparison of magma evolution with the Late Paleocene to Middle-Eocene (58–45 Ma) magmatism.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187187","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}
Pub Date : 2024-08-06DOI: 10.1016/j.chemer.2024.126169
Namık Aysal, Nurullah Hanilçi, Sinan Öngen, Cem Kasapçı, Fatma Şişman Tükel, Marcel Guillong, Mayuko Fukuyama, Nicole Leonard, Elif Varol
On the Biga Peninsula (NW Türkiye) Oligo-Miocene felsic plutonic intrusions extend vast regions. Skarn zones have developed around South Yenice plutons in this zone, which Show a rich potential for contact metamorphic diversity and mineralization, depending the host rock variety. Contact metamorphic zones and skarn occurrences have been mapped and determined. UPb dating was performed on garnets, and ages of 25.26 ± 0.30 Ma and 26.01 ± 1.02 Ma were yielded from Islıkçatıdere, and 24.85 ± 1.68 Ma, 25.81 ± 3.97 Ma and 21.03 ± 0.38 Ma from Namazgah skarn zones, respectively. UPb zircon dating of the Hıdırlar, Kurtlar and Namazgah plutons yielded ages of 26.33 ± 0.3, 25.39 ± 055 and 24.79 ± 0.38 Ma. These ages prove that the ages obtained from the skarn zone and the parent plutons are compatible. Garnet mineral chemistry and trace element analyses, when evaluated together with limited fluid inclusion data, indicate that the study area may be important in terms of potential iron, copper, lead and zinc mineralization.
{"title":"In-situ LA-ICP-MS U[sbnd]Pb dating and geochemistry of garnet skarn occurrences related to South Yenice plutons, NW Türkiye","authors":"Namık Aysal, Nurullah Hanilçi, Sinan Öngen, Cem Kasapçı, Fatma Şişman Tükel, Marcel Guillong, Mayuko Fukuyama, Nicole Leonard, Elif Varol","doi":"10.1016/j.chemer.2024.126169","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126169","url":null,"abstract":"On the Biga Peninsula (NW Türkiye) Oligo-Miocene felsic plutonic intrusions extend vast regions. Skarn zones have developed around South Yenice plutons in this zone, which Show a rich potential for contact metamorphic diversity and mineralization, depending the host rock variety. Contact metamorphic zones and skarn occurrences have been mapped and determined. UPb dating was performed on garnets, and ages of 25.26 ± 0.30 Ma and 26.01 ± 1.02 Ma were yielded from Islıkçatıdere, and 24.85 ± 1.68 Ma, 25.81 ± 3.97 Ma and 21.03 ± 0.38 Ma from Namazgah skarn zones, respectively. UPb zircon dating of the Hıdırlar, Kurtlar and Namazgah plutons yielded ages of 26.33 ± 0.3, 25.39 ± 055 and 24.79 ± 0.38 Ma. These ages prove that the ages obtained from the skarn zone and the parent plutons are compatible. Garnet mineral chemistry and trace element analyses, when evaluated together with limited fluid inclusion data, indicate that the study area may be important in terms of potential iron, copper, lead and zinc mineralization.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187188","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}
Pub Date : 2024-07-01DOI: 10.1016/j.chemer.2024.126167
İbrahim Akpınar, Yılmaz Demir, N. Aysal, Nurullah Hani̇lçi̇, Kıymet Deniz, Yusuf Kaan Kadıoğlu, Martin Yates, Emin Çiftçi
{"title":"Mineralogy, ore genesis and zircon U Pb age characteristics of the Cerattepe Cu Au (±Zn) deposit (Artvin, NE Turkey)","authors":"İbrahim Akpınar, Yılmaz Demir, N. Aysal, Nurullah Hani̇lçi̇, Kıymet Deniz, Yusuf Kaan Kadıoğlu, Martin Yates, Emin Çiftçi","doi":"10.1016/j.chemer.2024.126167","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126167","url":null,"abstract":"","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"35 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141843480","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}
Pub Date : 2024-06-20DOI: 10.1016/j.chemer.2024.126159
Yazgul Nugumanova, Anna Doroshkevich, Anastasia Kalugina, Dmitry Chebotarev, Ivan Izbrodin, Tong Hou
This paper presents data on the age and trace element composition of perovskites from dykes of ultramafic lamprophyres (aillikites) of the Zima alkaline-ultramafic carbonatite complex (Bolshaya Tagna and Bushkanay) located within the Urik-Iya graben, Eastern Sayan region, southern margin of the Siberian craton. The studied samples exhibit similar textural and structural features but differ slightly in the mineral composition of the groundmass. They have a porphyritic structure, a massive texture, and consist of olivine macrocrystals embedded in a fully crystallized groundmass composed of perovskite, apatite, spinel, phlogopite, garnet, carbonates, clinopyroxene and other minerals. The macrocrystals quantity varies between 40 and 50 vol%. With the exception of a single sample from the Bushkanay dyke, olivine is entirely replaced by serpentine and/or talc.
{"title":"Age and composition of perovskite in ultramafic lamprophyres from the Zima alkaline-ultramafic carbonatite complex, the southern margin of the Siberian craton: Petrogenetic implications","authors":"Yazgul Nugumanova, Anna Doroshkevich, Anastasia Kalugina, Dmitry Chebotarev, Ivan Izbrodin, Tong Hou","doi":"10.1016/j.chemer.2024.126159","DOIUrl":"https://doi.org/10.1016/j.chemer.2024.126159","url":null,"abstract":"This paper presents data on the age and trace element composition of perovskites from dykes of ultramafic lamprophyres (aillikites) of the Zima alkaline-ultramafic carbonatite complex (Bolshaya Tagna and Bushkanay) located within the Urik-Iya graben, Eastern Sayan region, southern margin of the Siberian craton. The studied samples exhibit similar textural and structural features but differ slightly in the mineral composition of the groundmass. They have a porphyritic structure, a massive texture, and consist of olivine macrocrystals embedded in a fully crystallized groundmass composed of perovskite, apatite, spinel, phlogopite, garnet, carbonates, clinopyroxene and other minerals. The macrocrystals quantity varies between 40 and 50 vol%. With the exception of a single sample from the Bushkanay dyke, olivine is entirely replaced by serpentine and/or talc.","PeriodicalId":12522,"journal":{"name":"Geochemistry","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530518","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}
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