Pub Date : 2012-12-01DOI: 10.1080/09853111.2013.858955
P. Speciale, E. Catlos, G. Yıldız, Timothy A. Shin, K. N. Black
The Beypazarı granitoid is emplaced in a Late Cretaceous volcanic arc in north central Turkey and provides evidence for processes that occurred during the closure of the Neo-Tethys Ocean. Zircons from its northern granodiorite and quartz monzonite exposure are dated in rock thin section and display characteristic igneous zoning in cathodoluminescence (CL). Its oldest Late Cretaceous ages (95.4 ± 4.2–91.3 ± 6.5 Ma, 238U/206Pb, ±1σ) time early crystallization from rising melts, but inspection of the youngest grains in composite CL–secondary electron images shows they are located along grain boundaries surrounded by alteration textures and were possibly affected by fluid-driven metamorphism. Ages obtained from zircon mid-rims (82.7 ± 6.0–70.5 ± 3.4 Ma) record continuous crystallization of the pluton. Here, we model the Late Cretaceous development of the Beypazarı granitoid wherein subduction of Neo-Tethys Oceanic plate, multiple injections and mixing of magma, and crustal contribution during ascent are the cause of geochemical heterogeneities within the pluton and account for protracted zircon crystallization. The model speculates that the pluton is in the overriding tectonic plate of a series of stacked, north-dipping subduction zones that record the closure of Neo-Tethys ocean basins during the geologic assembly of Turkey.
{"title":"Zircon ages from the Beypazarı granitoid pluton (north central Turkey): tectonic implications","authors":"P. Speciale, E. Catlos, G. Yıldız, Timothy A. Shin, K. N. Black","doi":"10.1080/09853111.2013.858955","DOIUrl":"https://doi.org/10.1080/09853111.2013.858955","url":null,"abstract":"The Beypazarı granitoid is emplaced in a Late Cretaceous volcanic arc in north central Turkey and provides evidence for processes that occurred during the closure of the Neo-Tethys Ocean. Zircons from its northern granodiorite and quartz monzonite exposure are dated in rock thin section and display characteristic igneous zoning in cathodoluminescence (CL). Its oldest Late Cretaceous ages (95.4 ± 4.2–91.3 ± 6.5 Ma, 238U/206Pb, ±1σ) time early crystallization from rising melts, but inspection of the youngest grains in composite CL–secondary electron images shows they are located along grain boundaries surrounded by alteration textures and were possibly affected by fluid-driven metamorphism. Ages obtained from zircon mid-rims (82.7 ± 6.0–70.5 ± 3.4 Ma) record continuous crystallization of the pluton. Here, we model the Late Cretaceous development of the Beypazarı granitoid wherein subduction of Neo-Tethys Oceanic plate, multiple injections and mixing of magma, and crustal contribution during ascent are the cause of geochemical heterogeneities within the pluton and account for protracted zircon crystallization. The model speculates that the pluton is in the overriding tectonic plate of a series of stacked, north-dipping subduction zones that record the closure of Neo-Tethys ocean basins during the geologic assembly of Turkey.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"162 - 182"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858955","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552389","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 : 2012-12-01DOI: 10.1080/09853111.2013.858949
N. Şahin, D. Altıner, M. Bülent Ercengiz
Detailed stratigraphic studies on the Middle-Upper Permian rocks of the Tahtalıdağ nappe (Antalya Nappes), largely exposed along the Güzelsu Corridor in central Taurides, have revealed the presence of basaltic volcanic rocks intercalated within the shallow-marine fossiliferous carbonate successions. Vitrophyric basaltic extrusions producing distinct pillows in the Kızılbağ Formation severely dolomitized the associated carbonate rocks.The coeval Çukurköy Formation, devoid of volcanic layers, is also exposed in the same corridor and was probably representing a part of the carbonate platform bordering this volcanic activity. The Middle-Upper Permian successions of the Kızılbağ and Çukurköy Formations have been calibrated based on a foraminiferal zonation and a Capitanian age has been assigned to the basaltic interval. Basalts are also chronostratigraphically located just below a horizon interpreted as the mid-Capitanian mass extinction event. Based on these data, two fundamental conclusions can be driven from this study. The discovery of basaltic volcanism brings a strong evidence for a much longer history about the rift-associated volcanic events in the Antalya Nappes. The Capitanian volcanic rocks are contemporaneous with the Emeishan Large Igneous Province in South China which is linked to the mid-Capitanian mass extinction event.
{"title":"Discovery of Middle Permian volcanism in the Antalya Nappes, southern Turkey: tectonic significance and global meaning","authors":"N. Şahin, D. Altıner, M. Bülent Ercengiz","doi":"10.1080/09853111.2013.858949","DOIUrl":"https://doi.org/10.1080/09853111.2013.858949","url":null,"abstract":"Detailed stratigraphic studies on the Middle-Upper Permian rocks of the Tahtalıdağ nappe (Antalya Nappes), largely exposed along the Güzelsu Corridor in central Taurides, have revealed the presence of basaltic volcanic rocks intercalated within the shallow-marine fossiliferous carbonate successions. Vitrophyric basaltic extrusions producing distinct pillows in the Kızılbağ Formation severely dolomitized the associated carbonate rocks.The coeval Çukurköy Formation, devoid of volcanic layers, is also exposed in the same corridor and was probably representing a part of the carbonate platform bordering this volcanic activity. The Middle-Upper Permian successions of the Kızılbağ and Çukurköy Formations have been calibrated based on a foraminiferal zonation and a Capitanian age has been assigned to the basaltic interval. Basalts are also chronostratigraphically located just below a horizon interpreted as the mid-Capitanian mass extinction event. Based on these data, two fundamental conclusions can be driven from this study. The discovery of basaltic volcanism brings a strong evidence for a much longer history about the rift-associated volcanic events in the Antalya Nappes. The Capitanian volcanic rocks are contemporaneous with the Emeishan Large Igneous Province in South China which is linked to the mid-Capitanian mass extinction event.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"286 - 304"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858949","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552053","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 : 2012-12-01DOI: 10.1080/09853111.2013.858954
F. Şengün, P. Davis, İ. Tunç, E. Yi̇ği̇tbaş
The Biga Peninsula in northwest Turkey contains high-pressure metabasic eclogite that occur in two localities; as lenses within a 2 km long, 500 m thick quartz-phengite schist slice that is in turn found in the greenschist-facies metasedimentary rocks of the Çamlıca metamorphics, in Çamlıca area, and in two north-south elongated eclogites occurring as a tectonic slice between Kazdağ Massif and Çetmi Group, in Çetmi area. The P-T conditions under which these two exposures of eclogites formed are important to quantify the tectonic processes of subduction, exhumation and emplacement that high-pressure rocks of the Biga Peninsula record. New geochemical data suggest that both protoliths were N-type MORB basalt with high TiO2 and K2O–Na2O content and Nb/Y ratios. Most eclogite samples have tholeiitic signatures volcanic arc settings. ∑REE abundances range from 47.55 to 107.4 ppm. Europium anomalies are slightly variable (Eu/Eu* = 0.9–1.1) and trace element contents are similar to typical MORB based on tectonic discrimination diagrams. All eclogite protoliths were probably derived from depleted mantle source, modified by fluids within the subduction zone. The high-P mineral assemblage in eclogites from both regions is omphacite + garnet + glaucophane + phengite + epidote + zoisite + quartz. The inclusions in garnet are glaucophane, quartz, phengite, Ca-amphibole and rutile. P-T conditions are similar to each other and constrained at 550–700 °C and 16–24 kbar. Geochemical data and mineral chemistry indicate that the eclogites in the Biga Peninsula represent oceanic crust processed at significant depths (50–80 km) within the subduction channel and were juxtaposed with greenschist facies as a tectonic slice in the accretionary complex at higher structural levels.
{"title":"Petrology and geochemistry of eclogites from the Biga Peninsula, Northwest Turkey","authors":"F. Şengün, P. Davis, İ. Tunç, E. Yi̇ği̇tbaş","doi":"10.1080/09853111.2013.858954","DOIUrl":"https://doi.org/10.1080/09853111.2013.858954","url":null,"abstract":"The Biga Peninsula in northwest Turkey contains high-pressure metabasic eclogite that occur in two localities; as lenses within a 2 km long, 500 m thick quartz-phengite schist slice that is in turn found in the greenschist-facies metasedimentary rocks of the Çamlıca metamorphics, in Çamlıca area, and in two north-south elongated eclogites occurring as a tectonic slice between Kazdağ Massif and Çetmi Group, in Çetmi area. The P-T conditions under which these two exposures of eclogites formed are important to quantify the tectonic processes of subduction, exhumation and emplacement that high-pressure rocks of the Biga Peninsula record. New geochemical data suggest that both protoliths were N-type MORB basalt with high TiO2 and K2O–Na2O content and Nb/Y ratios. Most eclogite samples have tholeiitic signatures volcanic arc settings. ∑REE abundances range from 47.55 to 107.4 ppm. Europium anomalies are slightly variable (Eu/Eu* = 0.9–1.1) and trace element contents are similar to typical MORB based on tectonic discrimination diagrams. All eclogite protoliths were probably derived from depleted mantle source, modified by fluids within the subduction zone. The high-P mineral assemblage in eclogites from both regions is omphacite + garnet + glaucophane + phengite + epidote + zoisite + quartz. The inclusions in garnet are glaucophane, quartz, phengite, Ca-amphibole and rutile. P-T conditions are similar to each other and constrained at 550–700 °C and 16–24 kbar. Geochemical data and mineral chemistry indicate that the eclogites in the Biga Peninsula represent oceanic crust processed at significant depths (50–80 km) within the subduction channel and were juxtaposed with greenschist facies as a tectonic slice in the accretionary complex at higher structural levels.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"248 - 266"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858954","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552170","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 : 2012-12-01DOI: 10.1080/09853111.2013.859345
U. K. Tekin, M. C. Göncüoğlu, L. Pandolfi, M. Marroni
Moderately to well-preserved, relatively diverse Middle and Late Triassic radiolarian assemblages have been obtained from the chert slide-blocks within the Late Cretaceous mélange of the IntraPontide Suture Zone at the Pelitören village to the NE of Kastamonu- Araç in northern Central Anatolia. In this locality, chert slide-blocks are tectonically overlain by metamorphic sole of the serpentinized peridotites belonging to the IntraPontide ophiolites. The oldest radiolarian assemblages, with the middle Late Anisian and late Early Ladinian ages, were found in green cherts in a pebbly mudstone. They are underlain by a larger slide-block composed of an alternation of radiolarian cherts and mudstones with late Early and early Late Carnian radiolarians. Another slide-block with cherts and mudstones between the sub-ophiolitic amphibolite and the Carnian cherts includes the late Early to early Middle Norian radiolarian assemblages. These new data reveal that the IntraPontide basin was already open during the Middle to Late Triassic time and deep enough for radiolarian cherts to deposit. Moreover, it suggests that the IntraPontide Ocean is contemporaneous with a number of inferred Paleo- and Neotethyan oceanic basins in SE Europe and NW Anatolia, which were proposed in copious tectonic models.
{"title":"Middle-Late Triassic radiolarian cherts from the Arkotdağ mélange in northern Turkey: implications for the life span of the northern Neotethyan branch","authors":"U. K. Tekin, M. C. Göncüoğlu, L. Pandolfi, M. Marroni","doi":"10.1080/09853111.2013.859345","DOIUrl":"https://doi.org/10.1080/09853111.2013.859345","url":null,"abstract":"Moderately to well-preserved, relatively diverse Middle and Late Triassic radiolarian assemblages have been obtained from the chert slide-blocks within the Late Cretaceous mélange of the IntraPontide Suture Zone at the Pelitören village to the NE of Kastamonu- Araç in northern Central Anatolia. In this locality, chert slide-blocks are tectonically overlain by metamorphic sole of the serpentinized peridotites belonging to the IntraPontide ophiolites. The oldest radiolarian assemblages, with the middle Late Anisian and late Early Ladinian ages, were found in green cherts in a pebbly mudstone. They are underlain by a larger slide-block composed of an alternation of radiolarian cherts and mudstones with late Early and early Late Carnian radiolarians. Another slide-block with cherts and mudstones between the sub-ophiolitic amphibolite and the Carnian cherts includes the late Early to early Middle Norian radiolarian assemblages. These new data reveal that the IntraPontide basin was already open during the Middle to Late Triassic time and deep enough for radiolarian cherts to deposit. Moreover, it suggests that the IntraPontide Ocean is contemporaneous with a number of inferred Paleo- and Neotethyan oceanic basins in SE Europe and NW Anatolia, which were proposed in copious tectonic models.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"305 - 319"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.859345","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552537","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 : 2012-12-01DOI: 10.1080/09853111.2014.882536
N. Aysal, Sinan Öngen, I. Peytcheva, M. Keskin
One of the pre-Jurassic metamorphic basements of the Western Sakarya Zone (NW Turkey) is the Havran Unit which contains metasedimentary (i.e. the Kalabak formation) and metaintrusive rocks of Devonian age. An LA-ICP-MS U-Pb zircon dating study was conducted on 125 zircon grains obtained from a metasedimentary rock to better understand the origin and evolution of the Kalabak formation. Around 107 of 175 spot analyses are concordant with rates 90–110% and the zircon ages vary between 426 ± 5.2 and 3406.9 ± 195.7 Ma. Zircon populations cluster in ranges: 426 ± 5.2–535 ± 13 Ma (8.4%, Palaeozoic), 549 ± 14–999 ± 11 Ma (54.21%, Neoproterozoic), 1012 ± 200–1543 ± 50 Ma (6.54%, Mesoproterozoic), 1736 ± 123–2414 ± 58 Ma (18.7%, Palaeoproterozoic), and 2512 ± 30–3406.9 ± 195.7 Ma (12.15%, Archean). Dominating Neoproterozoic ages notate Cadomian-Avalonian terrains and Mesoproterozoic ages should mainly be related to Avalon terrains. The Karacabey metagranite consists of coarse-grained, equigranular, hypidiomorphic, and rarely foliated monzogranite and granodiorite. It is located to the north of the town of Karacabey in the eastern part of the Biga Peninsula. Main mineral assemblage is quartz, K-feldspar, plagioclase, and biotite. Zircon, apatite, monazite, magnetite, and sphene occur as accessory phases. Aluminum Saturation Index (ASI) values vary between 0.91 and 1.63, indicating the pluton as a metaluminous-peraluminous, I-type granite. The metagranite samples are plotted in the high-K-calcalkaline field on the SiO2 vs. K2O diagram. N-MORB-normalised spidergrams display a profound enrichment in the large-ion lithophile elements (LILE), light rare earth elements (LREE), and depletion in high field strength elements, suggesting that its genesis relates to hydrous melting of a mantle wedge in a subduction zone and/or melting of subduction zone-influenced source areas. Chondrite-normalised rare earth element spidergrams are indicative of the importance of plagioclase and amphibole fractionation. In tectonic discrimination diagrams, all of the metagranite samples fall into the volcanic arc granite and late post-collisional granite fields. U/Pb LA-ICP-MS zircon dating of the metagranite yielded an age of 400.3 ± 1.4 Ma (Early Devonian), interpreted as the age of igneous crystallisation. These age data show that the Karacabey metagranite is a member of the lower to mid Devonian granites, recently described from the Biga Peninsula. In light of these findings, we argue that the Havran Unit was an exotic terrain which possibly was once a part of far-travelled Avalon terrains and was attached to Sakarya Zone.
{"title":"Origin and evolution of the Havran Unit, Western Sakarya basement (NW Turkey): new LA-ICP-MS U-Pb dating of the metasedimentary-metagranitic rocks and possible affiliation to Avalonian microcontinent","authors":"N. Aysal, Sinan Öngen, I. Peytcheva, M. Keskin","doi":"10.1080/09853111.2014.882536","DOIUrl":"https://doi.org/10.1080/09853111.2014.882536","url":null,"abstract":"One of the pre-Jurassic metamorphic basements of the Western Sakarya Zone (NW Turkey) is the Havran Unit which contains metasedimentary (i.e. the Kalabak formation) and metaintrusive rocks of Devonian age. An LA-ICP-MS U-Pb zircon dating study was conducted on 125 zircon grains obtained from a metasedimentary rock to better understand the origin and evolution of the Kalabak formation. Around 107 of 175 spot analyses are concordant with rates 90–110% and the zircon ages vary between 426 ± 5.2 and 3406.9 ± 195.7 Ma. Zircon populations cluster in ranges: 426 ± 5.2–535 ± 13 Ma (8.4%, Palaeozoic), 549 ± 14–999 ± 11 Ma (54.21%, Neoproterozoic), 1012 ± 200–1543 ± 50 Ma (6.54%, Mesoproterozoic), 1736 ± 123–2414 ± 58 Ma (18.7%, Palaeoproterozoic), and 2512 ± 30–3406.9 ± 195.7 Ma (12.15%, Archean). Dominating Neoproterozoic ages notate Cadomian-Avalonian terrains and Mesoproterozoic ages should mainly be related to Avalon terrains. The Karacabey metagranite consists of coarse-grained, equigranular, hypidiomorphic, and rarely foliated monzogranite and granodiorite. It is located to the north of the town of Karacabey in the eastern part of the Biga Peninsula. Main mineral assemblage is quartz, K-feldspar, plagioclase, and biotite. Zircon, apatite, monazite, magnetite, and sphene occur as accessory phases. Aluminum Saturation Index (ASI) values vary between 0.91 and 1.63, indicating the pluton as a metaluminous-peraluminous, I-type granite. The metagranite samples are plotted in the high-K-calcalkaline field on the SiO2 vs. K2O diagram. N-MORB-normalised spidergrams display a profound enrichment in the large-ion lithophile elements (LILE), light rare earth elements (LREE), and depletion in high field strength elements, suggesting that its genesis relates to hydrous melting of a mantle wedge in a subduction zone and/or melting of subduction zone-influenced source areas. Chondrite-normalised rare earth element spidergrams are indicative of the importance of plagioclase and amphibole fractionation. In tectonic discrimination diagrams, all of the metagranite samples fall into the volcanic arc granite and late post-collisional granite fields. U/Pb LA-ICP-MS zircon dating of the metagranite yielded an age of 400.3 ± 1.4 Ma (Early Devonian), interpreted as the age of igneous crystallisation. These age data show that the Karacabey metagranite is a member of the lower to mid Devonian granites, recently described from the Biga Peninsula. In light of these findings, we argue that the Havran Unit was an exotic terrain which possibly was once a part of far-travelled Avalon terrains and was attached to Sakarya Zone.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"226 - 247"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2014.882536","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552583","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 : 2012-12-01DOI: 10.1080/09853111.2013.877241
Ökmen Sümer, U. Inci, H. Sözbilir
The Quaternary period on the western coast of Turkey is studied using sedimentological features and geochronological age data of the Söke-Milet Basin (SMB), which is a subsidiary to the Büyük Menderes Graben (BMG). Here, for the first time, we geochronologically document the Early Pleistocene shallow marine fan-deltaic succession in the Fevzipaşa Formation (basin-fill unit of the SMB), 15 km inland of the current Aegean coast and 150 m above current sea level. The formation outcrops at the western end of the BMG. It comprises an alluvial fan to freshwater carbonate, shallow marine fan-deltaic and alluvial fan depositional packages separated by intrabasinal unconformities. Based on conventional sedimentary data, seven different facies associations (FA) have been distinguished in the Fevzipaşa Formation: (FA 1) hyperconcentrated flow-generated lower alluvial fan deposits, (FA 2) freshwater lacustrine carbonate deposits, (FA 3) prodelta deposits, (FA 4) shallow marine fan-delta slope deposits, (FA 5) nearshore sandy mouth-bar-type fan-delta front deposits, (FA 6) alluvial fan-delta top deposits and (FA 7) hyperconcentrated flow-generated upper alluvial fan deposits. The shallow marine facies above the lower alluvial fan deposits, considered in conjunction with stratigraphical observations and geochronological and paleontological age data, suggest that a late Early Pleistocene transgression affected the Aegean region.
利用 y k Menderes地堑(BMG)的附属盆地Söke-Milet (SMB)的沉积学特征和年代学资料，对土耳其西海岸第四纪进行了研究。在这里，我们首次从地质年代学上记录了fevzipa组(SMB的盆地填充单元)早更新世浅海扇三角洲序列，该组位于当前爱琴海海岸内陆15公里处，海拔150米。该地层在BMG的西端露头。包括冲积扇-淡水碳酸盐岩、浅海扇-三角洲和以基底内不整合面分隔的冲积扇沉积包体。根据常规沉积资料，在fevzipa组中划分出7种不同的相组合(FA):(FA 1)下冲积扇高流速沉积，(FA 2)淡水湖相碳酸盐岩沉积，(FA 3)前三角洲沉积，(FA 4)浅海扇三角洲斜坡沉积，(FA 5)近岸砂质河口坝式扇三角洲前缘沉积，(FA 6)冲积扇三角洲顶部沉积，(FA 7)上冲积扇高流速沉积。下部冲积扇沉积之上的浅海相，结合地层观测、地质年代学和古生物学年龄资料，表明爱琴海地区受到早更新世晚期海侵的影响。
{"title":"Tectono-sedimentary evolution of an Early Pleistocene shallow marine fan-deltaic succession at the western coast of Turkey","authors":"Ökmen Sümer, U. Inci, H. Sözbilir","doi":"10.1080/09853111.2013.877241","DOIUrl":"https://doi.org/10.1080/09853111.2013.877241","url":null,"abstract":"The Quaternary period on the western coast of Turkey is studied using sedimentological features and geochronological age data of the Söke-Milet Basin (SMB), which is a subsidiary to the Büyük Menderes Graben (BMG). Here, for the first time, we geochronologically document the Early Pleistocene shallow marine fan-deltaic succession in the Fevzipaşa Formation (basin-fill unit of the SMB), 15 km inland of the current Aegean coast and 150 m above current sea level. The formation outcrops at the western end of the BMG. It comprises an alluvial fan to freshwater carbonate, shallow marine fan-deltaic and alluvial fan depositional packages separated by intrabasinal unconformities. Based on conventional sedimentary data, seven different facies associations (FA) have been distinguished in the Fevzipaşa Formation: (FA 1) hyperconcentrated flow-generated lower alluvial fan deposits, (FA 2) freshwater lacustrine carbonate deposits, (FA 3) prodelta deposits, (FA 4) shallow marine fan-delta slope deposits, (FA 5) nearshore sandy mouth-bar-type fan-delta front deposits, (FA 6) alluvial fan-delta top deposits and (FA 7) hyperconcentrated flow-generated upper alluvial fan deposits. The shallow marine facies above the lower alluvial fan deposits, considered in conjunction with stratigraphical observations and geochronological and paleontological age data, suggest that a late Early Pleistocene transgression affected the Aegean region.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"112 - 131"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.877241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552811","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 : 2012-12-01DOI: 10.1080/09853111.2013.877242
İ. Tunç, E. Yi̇ği̇tbaş, F. Şengün, Jana Wazeck, M. Hofmann, U. Linnemann
Metamorphic massifs of the Biga Peninsula can be divided into two approximately ENE–WSW-trending belts. It is believed that these two belts represent two different tectonic zones separated by a NE-trending Alpine ophiolitic suture. The Sakarya Zone lies to the S–SE of this Alpine suture, and consists of the Kazdağ metamorphic complex which is tectonically overlain by the Permo-Triassic Karakaya Complex. The metamorphic rocks, as an Alpine edifice located N–NW of the suture, have been assigned to the Rhodope and Serbo-Macedonian massifs of Bulgaria and Greece. The northern metamorphic belt is represented by the Karadağ Massif in the west, which has been evaluated as a different unit from the others, the Karabiga Massif in the east and the Çamlıca Massif between them. All three massifs are mapped in detail in light of previous studies and LA–ICP–MS U-Pb zircon dating was applied to stratigraphically compare them. Contrary to previous studies, our data indicate that the basement metamorphic associations in these three areas show similar characteristics concerning their stratigraphical and lithological aspects and also spatial distribution of their outcrops. U-Pb LA–ICP–MS dating of zircons from the three individual metamorphic massifs yielded the following data: maximum sedimentation ages of the protolith of mica schists in the range of 559 ± 17 to 582 ± 30 Ma; crystallisation age of the protolith of metavolcanic rocks of 577 ± 20 Ma; and crystallisation age of the protolith of eclogites at 565 ± 9 Ma. These ages clearly show that the metamorphic units of the northern massifs are comparable to each other. Also, the U-Pb zircon concordia diagrams from these three metamorphic massifs show remarkably similar patterns. In addition to the similar maximum sedimentation ages for all mica schists with crystallisation ages of the protoliths of the metabasic rocks, there are two major complex tectono-thermal overprints (episodic lead loss events), at c. 330–300 Ma (Variscan?) and c. 100–10 Ma (Alpine and late Alpine?), respectively. Field mapping and analytical data indicate that the basement rocks of the northern massifs in the Biga Peninsula have a correlative Late Ediacaran to Early Cambrian stratigraphic range. In part, Permian strata unconformably overlie basement rocks in the Karadağ Massif. Both tectono-thermal events are demonstrated by coeval episodic lead loss of many zircons in all samples from all areas. Finally, the results of this research do not support an Alpine suture between the two metamorphic belts of the Biga Peninsula. Therefore, the geological evolution of the region might require reevaluation.
{"title":"U-Pb zircon geochronology of northern metamorphic massifs in the Biga Peninsula (NW Anatolia-Turkey): new data and a new approach to understand the tectonostratigraphy of the region","authors":"İ. Tunç, E. Yi̇ği̇tbaş, F. Şengün, Jana Wazeck, M. Hofmann, U. Linnemann","doi":"10.1080/09853111.2013.877242","DOIUrl":"https://doi.org/10.1080/09853111.2013.877242","url":null,"abstract":"Metamorphic massifs of the Biga Peninsula can be divided into two approximately ENE–WSW-trending belts. It is believed that these two belts represent two different tectonic zones separated by a NE-trending Alpine ophiolitic suture. The Sakarya Zone lies to the S–SE of this Alpine suture, and consists of the Kazdağ metamorphic complex which is tectonically overlain by the Permo-Triassic Karakaya Complex. The metamorphic rocks, as an Alpine edifice located N–NW of the suture, have been assigned to the Rhodope and Serbo-Macedonian massifs of Bulgaria and Greece. The northern metamorphic belt is represented by the Karadağ Massif in the west, which has been evaluated as a different unit from the others, the Karabiga Massif in the east and the Çamlıca Massif between them. All three massifs are mapped in detail in light of previous studies and LA–ICP–MS U-Pb zircon dating was applied to stratigraphically compare them. Contrary to previous studies, our data indicate that the basement metamorphic associations in these three areas show similar characteristics concerning their stratigraphical and lithological aspects and also spatial distribution of their outcrops. U-Pb LA–ICP–MS dating of zircons from the three individual metamorphic massifs yielded the following data: maximum sedimentation ages of the protolith of mica schists in the range of 559 ± 17 to 582 ± 30 Ma; crystallisation age of the protolith of metavolcanic rocks of 577 ± 20 Ma; and crystallisation age of the protolith of eclogites at 565 ± 9 Ma. These ages clearly show that the metamorphic units of the northern massifs are comparable to each other. Also, the U-Pb zircon concordia diagrams from these three metamorphic massifs show remarkably similar patterns. In addition to the similar maximum sedimentation ages for all mica schists with crystallisation ages of the protoliths of the metabasic rocks, there are two major complex tectono-thermal overprints (episodic lead loss events), at c. 330–300 Ma (Variscan?) and c. 100–10 Ma (Alpine and late Alpine?), respectively. Field mapping and analytical data indicate that the basement rocks of the northern massifs in the Biga Peninsula have a correlative Late Ediacaran to Early Cambrian stratigraphic range. In part, Permian strata unconformably overlie basement rocks in the Karadağ Massif. Both tectono-thermal events are demonstrated by coeval episodic lead loss of many zircons in all samples from all areas. Finally, the results of this research do not support an Alpine suture between the two metamorphic belts of the Biga Peninsula. Therefore, the geological evolution of the region might require reevaluation.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"202 - 225"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.877242","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552896","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 : 2012-12-01DOI: 10.1080/09853111.2013.858945
Y. L. Ekinci, E. Yi̇ği̇tbaş
The Biga Peninsula, the complex geological structure of which has attracted intense attention so far, is located in the north-western part of Anatolia, Turkey. The Peninsula is tectonically very important region where different tectonic zones meet and comprises various kinds of sedimentary, metamorphic and igneous rocks. Among these rocks, igneous rocks occupy a considerably amount of areas in the Biga Peninsula and they are mostly associated with geothermal systems and mineral deposits, and therefore they play an important role in the geology of the Peninsula. In this paper, derived results concerning the geological features and subsurface structures of the igneous rocks in the Peninsula are presented based on analyzing the airborne magnetic anomalies. To this end, a MATLAB-based toolkit named as Gravity and Magnetic Interpretation (GMINTERP) that is composed of a set of linked functions in conjunction with a graphical user interface was developed and used for the interpretation of the airborne magnetic anomalies. Some linear transformations and derivative-based techniques were performed to process the potential field data-set and also to help build a general understanding of the geological details. The close agreement between the derived geophysical anomaly maps and the well-known surface geology map of the Biga Peninsula helped us discuss the geological implications of the geophysical traces. This study also indicated that the developed interactive data processing toolkit may assist geological interpretation even in the areas whose subsurface structure is poorly known.
{"title":"A geophysical approach to the igneous rocks in the Biga Peninsula (NW Turkey) based on airborne magnetic anomalies: geological implications","authors":"Y. L. Ekinci, E. Yi̇ği̇tbaş","doi":"10.1080/09853111.2013.858945","DOIUrl":"https://doi.org/10.1080/09853111.2013.858945","url":null,"abstract":"The Biga Peninsula, the complex geological structure of which has attracted intense attention so far, is located in the north-western part of Anatolia, Turkey. The Peninsula is tectonically very important region where different tectonic zones meet and comprises various kinds of sedimentary, metamorphic and igneous rocks. Among these rocks, igneous rocks occupy a considerably amount of areas in the Biga Peninsula and they are mostly associated with geothermal systems and mineral deposits, and therefore they play an important role in the geology of the Peninsula. In this paper, derived results concerning the geological features and subsurface structures of the igneous rocks in the Peninsula are presented based on analyzing the airborne magnetic anomalies. To this end, a MATLAB-based toolkit named as Gravity and Magnetic Interpretation (GMINTERP) that is composed of a set of linked functions in conjunction with a graphical user interface was developed and used for the interpretation of the airborne magnetic anomalies. Some linear transformations and derivative-based techniques were performed to process the potential field data-set and also to help build a general understanding of the geological details. The close agreement between the derived geophysical anomaly maps and the well-known surface geology map of the Biga Peninsula helped us discuss the geological implications of the geophysical traces. This study also indicated that the developed interactive data processing toolkit may assist geological interpretation even in the areas whose subsurface structure is poorly known.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"267 - 285"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858945","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552023","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 : 2012-12-01DOI: 10.1080/09853111.2013.861997
A. Polat, O. Tatar, H. Gürsoy, C. Çağlar Yalçiner, A. Büyüksaraç
This study has aimed to evaluate the current tectonic structure of the Suşehri Basin located on the eastern part of the North Anatolian Fault Zone (NAFZ), one of the most important active faults in Turkey. The work extends earlier investigations of offset and seismicity on the NAFZ and tests a range of evolutionary models. In this study, buried faults have been determined from Ground penetrating radar and magnetic anomalies and possible discontinuities identified by interpolating these data in a region between Gölova and Suşehri. The discontinuities are shown to be linked to negative flower structures formed within the strike-slip fault zone. Quickbird satellite images have been used to map faults and produce kinematic analyses which show that the active stress regime is dominantly strike-slip. However, normal faults and oblique-slip faults are also observed in the basin together with strike-slip faults and the stress regime creating the strike-slip faults is shown to have formed under NW-SE directed transtension. In addition, oblique faults formed under an extensional regime with NNE-SSW direction also occur in the Suşehri Basin as subsets formed under the constraining strike-slip regime. We conclude that the Suşehri Basin started to grow as a fault wedge basin following which it transformed into a pull-apart basin by a south splay on the NAFZ so it is now dominantly a transtensional pull-apart feature.
{"title":"Two-phased evolution of the Suşehri Basin on the North Anatolian Fault Zone, Turkey","authors":"A. Polat, O. Tatar, H. Gürsoy, C. Çağlar Yalçiner, A. Büyüksaraç","doi":"10.1080/09853111.2013.861997","DOIUrl":"https://doi.org/10.1080/09853111.2013.861997","url":null,"abstract":"This study has aimed to evaluate the current tectonic structure of the Suşehri Basin located on the eastern part of the North Anatolian Fault Zone (NAFZ), one of the most important active faults in Turkey. The work extends earlier investigations of offset and seismicity on the NAFZ and tests a range of evolutionary models. In this study, buried faults have been determined from Ground penetrating radar and magnetic anomalies and possible discontinuities identified by interpolating these data in a region between Gölova and Suşehri. The discontinuities are shown to be linked to negative flower structures formed within the strike-slip fault zone. Quickbird satellite images have been used to map faults and produce kinematic analyses which show that the active stress regime is dominantly strike-slip. However, normal faults and oblique-slip faults are also observed in the basin together with strike-slip faults and the stress regime creating the strike-slip faults is shown to have formed under NW-SE directed transtension. In addition, oblique faults formed under an extensional regime with NNE-SSW direction also occur in the Suşehri Basin as subsets formed under the constraining strike-slip regime. We conclude that the Suşehri Basin started to grow as a fault wedge basin following which it transformed into a pull-apart basin by a south splay on the NAFZ so it is now dominantly a transtensional pull-apart feature.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"132 - 145"},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.861997","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552249","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 : 2012-06-01DOI: 10.1080/09853111.2013.813741
U. Temiz
Manisa Fault is a geomorphologically distinct normal dip-slip fault, which oversees the southern edge of the Manisa Graben that is a continuum of the Gediz Graben towards the west. This study aims to determine the neotectonic activity of the Manisa Fault and the most recent time of the change in its stress condition through age-dating data obtained by using 230Th/234U dating methodology applied on the calcite coating that develops over hanging-wall of the Manisa Fault and the calcite veins that occur as fracture fillings. The age of the calcite precipitations associated with the Manisa Fault was determined to be between 307 ± 203 and 444 ± 101 ka by using the 230Th/234U dating method. Evaluation of the carbonate precipitations on the Manisa Fault along with the age data and the kinematic indicators ascertained that the Manisa Fault switched to a dip-slip normal faulting character from Middle Pleistocene onwards and that the region was under the effect of a NE–SW directional extensional regime. In addition, the opening rate was attempted to be determined using the roll-over anticline structure that advanced depending upon the movement of the fault on the upper horizontal strata of colluviums, which developed in association with the Manisa Fault. Along with the evaluation of the rise in the horizontal stratification in colluvium and the obtained age data, opening rate of the Manisa Fault was determined as 0.01 mm y−1.
马尼萨断层是一条地貌独特的正常倾滑断层，它监督着马尼萨地堑的南部边缘，马尼萨地堑是格迪兹地堑向西的连续体。本研究旨在通过对马尼萨断层上盘上发育的方解石包层和裂缝充填的方解石脉采用2330 /234U测年方法获得的年龄测年数据，确定马尼萨断层的新构造活动及其应力状态变化的最新时间。采用230Th/234U定年法确定了与马尼萨断裂有关的方解石沉淀年龄在307±203 ~ 444±101 ka之间。通过对马尼萨断裂带碳酸盐岩沉积的评价，结合年龄资料和运动学指标，确定了马尼萨断裂带中更新世以来转为倾滑正断裂特征，该地区受NE-SW向伸展作用的影响。此外，还试图利用翻滚背斜构造来确定打开速率，该构造的推进取决于断层在与马尼萨断层一起发育的砾岩上部水平地层上的运动。通过对崩积层水平分层上升程度的评价和获得的年龄资料，确定马尼萨断裂的张开率为0.01 mm y - 1。
{"title":"Age of fault reactivation by using U/Th dating method of carbonate precipitates: an example from the active Manisa Fault (West Turkey)","authors":"U. Temiz","doi":"10.1080/09853111.2013.813741","DOIUrl":"https://doi.org/10.1080/09853111.2013.813741","url":null,"abstract":"Manisa Fault is a geomorphologically distinct normal dip-slip fault, which oversees the southern edge of the Manisa Graben that is a continuum of the Gediz Graben towards the west. This study aims to determine the neotectonic activity of the Manisa Fault and the most recent time of the change in its stress condition through age-dating data obtained by using 230Th/234U dating methodology applied on the calcite coating that develops over hanging-wall of the Manisa Fault and the calcite veins that occur as fracture fillings. The age of the calcite precipitations associated with the Manisa Fault was determined to be between 307 ± 203 and 444 ± 101 ka by using the 230Th/234U dating method. Evaluation of the carbonate precipitations on the Manisa Fault along with the age data and the kinematic indicators ascertained that the Manisa Fault switched to a dip-slip normal faulting character from Middle Pleistocene onwards and that the region was under the effect of a NE–SW directional extensional regime. In addition, the opening rate was attempted to be determined using the roll-over anticline structure that advanced depending upon the movement of the fault on the upper horizontal strata of colluviums, which developed in association with the Manisa Fault. Along with the evaluation of the rise in the horizontal stratification in colluvium and the obtained age data, opening rate of the Manisa Fault was determined as 0.01 mm y−1.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":"25 1","pages":"1 - 11"},"PeriodicalIF":1.5,"publicationDate":"2012-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.813741","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59550850","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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