Pub Date : 2020-01-01DOI: 10.1080/09853111.2020.1829904
I. Kocak
ABSTRACT Sarıhıdır travertines and associated manganese mineralization are located in an area known as the Central Anatolian Volcanic Province (CAVP). The topic of the study, the Sarıhıdır manganese mineralization, was deposited in association with fault zones in this tectonically-active region. Paragenesis of the mineralization includes pyrolusite, rhodochrosite and goethite with gangue minerals of calcite and quartz observed. Diagrams drawn using major oxide and trace elements like Fe–Mn–(Ni+Co+Cu)×10, Fe-Si×2-Mn, Co/Ni vs Cu+Co+Ni, Si/Al, Na/Mg, Fe/Ti vs. Al/(Al+Fe+Mn), Co+Ni/As+Cu+Mo+Pb+V+ Zn and FeO–MnO2–10× MgO show the mineralization found in the region is sourced in the hydrothermal field. The low total REE values and LREE>HREE ratio indicate the effect of hydrothermal solutions. Additionally, Ce, Eu and Ceanom anomalies indicate the source of the mineralization was hydrothermal with oxic-anoxic formation environment. The Y/Ho ratio is mean 30.1 which is lower compared to hydrothermal fluids. Mean values are δ13CPDB 12.24‰ and δ18OPDB 10.87‰ indicating deposition from fluids with a deep CO2 component. In conclusion, the Sarıhıdır mineralization and travertine were determined to have formed about 50–53 ka (Upper Pleistocene) based on U-series age data, as fault-controlled, hydrothermal-sourced mineralization.
{"title":"Sarıhıdır manganese mineralization related to travertine, Central Anatolian Volcanic Province, Turkey","authors":"I. Kocak","doi":"10.1080/09853111.2020.1829904","DOIUrl":"https://doi.org/10.1080/09853111.2020.1829904","url":null,"abstract":"ABSTRACT Sarıhıdır travertines and associated manganese mineralization are located in an area known as the Central Anatolian Volcanic Province (CAVP). The topic of the study, the Sarıhıdır manganese mineralization, was deposited in association with fault zones in this tectonically-active region. Paragenesis of the mineralization includes pyrolusite, rhodochrosite and goethite with gangue minerals of calcite and quartz observed. Diagrams drawn using major oxide and trace elements like Fe–Mn–(Ni+Co+Cu)×10, Fe-Si×2-Mn, Co/Ni vs Cu+Co+Ni, Si/Al, Na/Mg, Fe/Ti vs. Al/(Al+Fe+Mn), Co+Ni/As+Cu+Mo+Pb+V+ Zn and FeO–MnO2–10× MgO show the mineralization found in the region is sourced in the hydrothermal field. The low total REE values and LREE>HREE ratio indicate the effect of hydrothermal solutions. Additionally, Ce, Eu and Ceanom anomalies indicate the source of the mineralization was hydrothermal with oxic-anoxic formation environment. The Y/Ho ratio is mean 30.1 which is lower compared to hydrothermal fluids. Mean values are δ13CPDB 12.24‰ and δ18OPDB 10.87‰ indicating deposition from fluids with a deep CO2 component. In conclusion, the Sarıhıdır mineralization and travertine were determined to have formed about 50–53 ka (Upper Pleistocene) based on U-series age data, as fault-controlled, hydrothermal-sourced mineralization.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2020.1829904","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41476715","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 : 2020-01-01DOI: 10.1080/09853111.2020.1809824
E. Gülyüz
ABSTRACT The Beypazarı Granitoid is an arc-related intrusion in the Central Pontides, Turkey. This study presents apatite fission track (AFT) ages of the intrusion to shed some light on collision-related cooling/exhumation history of the central Pontides. The AFT ages from different altitudes (506–805-1110 metres above sea level) of the Beypazarı Granitoid yield around 65 ± 3 Ma. This indicates a rapid cooling/exhumation for the intrusion around 65 Ma, which is attributed to the commencement of the collision event in the region. Integration of these ages and low-temperature thermochronology literature suggests a progressive collision propagation towards the margins of the collision system.
{"title":"Apatite fission track dating of the Beypazarı Granitoid: insight for the inception of collision along the Northern Neotethys, Turkey","authors":"E. Gülyüz","doi":"10.1080/09853111.2020.1809824","DOIUrl":"https://doi.org/10.1080/09853111.2020.1809824","url":null,"abstract":"ABSTRACT The Beypazarı Granitoid is an arc-related intrusion in the Central Pontides, Turkey. This study presents apatite fission track (AFT) ages of the intrusion to shed some light on collision-related cooling/exhumation history of the central Pontides. The AFT ages from different altitudes (506–805-1110 metres above sea level) of the Beypazarı Granitoid yield around 65 ± 3 Ma. This indicates a rapid cooling/exhumation for the intrusion around 65 Ma, which is attributed to the commencement of the collision event in the region. Integration of these ages and low-temperature thermochronology literature suggests a progressive collision propagation towards the margins of the collision system.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2020.1809824","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48218149","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 : 2019-01-01DOI: 10.1080/09853111.2019.1670414
D. Asiedu, M. Agoe, Prince Ofori Amponsah, P. Nude, C. Anani
ABSTRACT The Wa-Lawra Belt which is situated in the northern part of Ghana consists of Paleoproterozoic Birimian fine metasedimentary rocks metamorphosed to greenschist facies, particularly, in the western part. A whole-rock geochemical study of these metasedimentary rocks was undertaken to unravel their source area weathering, provenance and tectonic setting. Geochemical characteristics of the studied shales show that they are immature in nature and first cycle in origin, with little or no recycled component. Compared to Post-Archaean Australian Shales (PAAS), the studied shales indicate reduction in Zr, Hf, La, Nb, Th and Ta being the high field strength elements and evidences of transition metal enrichments in V, Ni, Sc, Co, and Cr. Major element geochemistry indicates that the shales were subjected to slight potassium metasomatism after deposition. Pre-metasomatized Chemical Index of Alteration calculations indicates that weak to moderate degree of chemical weathering took place at the sediment source area. Co-Th-La-Sc systematics reveals a combination of mafic and felsic provenances for the shales. Eu/Eu* together with values of Th/U and some abundances of trace elements show that the shales were mainly derived from juvenile rocks. Average REE model calculations suggest that the source materials are composed of about 49% basalt, 16% TTG and 35% granite.
{"title":"Geochemical constraints on provenance and source area weathering of metasedimentary rocks from the Paleoproterozoic (~2.1 Ga) Wa-Lawra Belt, southeastern margin of the West African Craton","authors":"D. Asiedu, M. Agoe, Prince Ofori Amponsah, P. Nude, C. Anani","doi":"10.1080/09853111.2019.1670414","DOIUrl":"https://doi.org/10.1080/09853111.2019.1670414","url":null,"abstract":"ABSTRACT The Wa-Lawra Belt which is situated in the northern part of Ghana consists of Paleoproterozoic Birimian fine metasedimentary rocks metamorphosed to greenschist facies, particularly, in the western part. A whole-rock geochemical study of these metasedimentary rocks was undertaken to unravel their source area weathering, provenance and tectonic setting. Geochemical characteristics of the studied shales show that they are immature in nature and first cycle in origin, with little or no recycled component. Compared to Post-Archaean Australian Shales (PAAS), the studied shales indicate reduction in Zr, Hf, La, Nb, Th and Ta being the high field strength elements and evidences of transition metal enrichments in V, Ni, Sc, Co, and Cr. Major element geochemistry indicates that the shales were subjected to slight potassium metasomatism after deposition. Pre-metasomatized Chemical Index of Alteration calculations indicates that weak to moderate degree of chemical weathering took place at the sediment source area. Co-Th-La-Sc systematics reveals a combination of mafic and felsic provenances for the shales. Eu/Eu* together with values of Th/U and some abundances of trace elements show that the shales were mainly derived from juvenile rocks. Average REE model calculations suggest that the source materials are composed of about 49% basalt, 16% TTG and 35% granite.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2019.1670414","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42009269","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 : 2019-01-01DOI: 10.1080/09853111.2019.1597677
F. Toksoy-Köksal
ABSTRACT Granitoids of the Ekecikdağ Igneous Association (Central Anatolia/Turkey) are products of collisional–post-collisional magmatism in the Ekecikdağ area. These granitoids are granodiorite, microgranite and leucogranite. Field relations of granodiorites with microgranites is obscured, but leucogranites intrude both rock types. Mean zircon laser ablation (LA)-ICP-MS 206Pb-238U ages of granodiorites and microgranites are 84.52 ± 0.93 Ma and 80.7 ± 1.6 Ma, respectively, and age of leucogranites is suggested as 80 Ma, based on field relations combined with 206Pb/238U and Rb-Sr ages. Crystallisation temperatures of granodiorites, microgranites and leucogranites are 728°C-848°C, 797°C-880°C, 704°C-809°C, respectively. Geochemical characteristics including Sr-Nd isotopic evidences infer a non-cogenetic character, as there is a high crustal contribution in I-type granodiorite sources, a crustal source with insignificant and significant mantle inputs in S-type microgranites and leucogranites, respectively. LA-ICP-MS Lu-Hf isotope data from zircons reveal their crustal nature (εHf(t): −1.3 ± 0.5 to −8.8 ± 0.5). Crustal melting linked to the Alpine thickening during the Late Cretaceous led to formation of heterogeneous sourced granitoids with crustal dominated sources in the Ekecikdağ area. Understanding of the nature and evolution of collisional Ekecikdağ granitoids is not only important to put contribution in the geodynamic evolution of Central Anatolia and surrounding Alpine area, but also to better understand systematics of collisional magmatic systems.
Ekecikdağ火成岩组合（安纳托利亚中部/土耳其）的花岗岩是Ekecikdağ地区碰撞-碰撞后岩浆作用的产物。这些花岗岩类为花岗闪长岩、微花岗岩和浅色花岗岩。花岗闪长岩与微花岗岩的野外关系不清楚，但浅色花岗岩侵入了这两种岩石类型。花岗闪长岩和微花岗岩的锆石激光烧蚀（LA）-ICP-MS206bb-238U平均年龄分别为84.52±0.93Ma和80.7±1.6Ma，根据场关系结合206Pb/238U和Rb-Sr年龄，建议隐色花岗岩的年龄为80Ma。花岗闪长岩、微花岗岩和浅色花岗岩的结晶温度分别为728°C-848°C、797°C-880°C和704°C-809°C。包括Sr-Nd同位素证据在内的地球化学特征推断出一种非共成因特征，因为I型花岗闪长岩源中有较高的地壳贡献，S型微花岗岩和浅色花岗岩中分别有不显著和显著的地幔输入。锆石的LA-ICP-MS Lu Hf同位素数据揭示了它们的地壳性质（εHf（t）：−1.3±0.5至−8.8±0.5）。与晚白垩世阿尔卑斯山脉增厚有关的地壳熔融导致Ekecikdağ地区形成了以地壳为主的非均质来源的花岗质岩石。了解碰撞Ekecikdağ花岗质岩石的性质和演化，不仅有助于对安纳托利亚中部及周围阿尔卑斯地区的地球动力学演化做出贡献，而且有助于更好地理解碰撞岩浆系统的系统学。
{"title":"On the geodynamics of the Alpine collisional granitoids from Central Anatolia: petrology, age and isotopic characteristics of the granitoids of the Ekecikdağ Igneous Association (Aksaray/Turkey)","authors":"F. Toksoy-Köksal","doi":"10.1080/09853111.2019.1597677","DOIUrl":"https://doi.org/10.1080/09853111.2019.1597677","url":null,"abstract":"ABSTRACT Granitoids of the Ekecikdağ Igneous Association (Central Anatolia/Turkey) are products of collisional–post-collisional magmatism in the Ekecikdağ area. These granitoids are granodiorite, microgranite and leucogranite. Field relations of granodiorites with microgranites is obscured, but leucogranites intrude both rock types. Mean zircon laser ablation (LA)-ICP-MS 206Pb-238U ages of granodiorites and microgranites are 84.52 ± 0.93 Ma and 80.7 ± 1.6 Ma, respectively, and age of leucogranites is suggested as 80 Ma, based on field relations combined with 206Pb/238U and Rb-Sr ages. Crystallisation temperatures of granodiorites, microgranites and leucogranites are 728°C-848°C, 797°C-880°C, 704°C-809°C, respectively. Geochemical characteristics including Sr-Nd isotopic evidences infer a non-cogenetic character, as there is a high crustal contribution in I-type granodiorite sources, a crustal source with insignificant and significant mantle inputs in S-type microgranites and leucogranites, respectively. LA-ICP-MS Lu-Hf isotope data from zircons reveal their crustal nature (εHf(t): −1.3 ± 0.5 to −8.8 ± 0.5). Crustal melting linked to the Alpine thickening during the Late Cretaceous led to formation of heterogeneous sourced granitoids with crustal dominated sources in the Ekecikdağ area. Understanding of the nature and evolution of collisional Ekecikdağ granitoids is not only important to put contribution in the geodynamic evolution of Central Anatolia and surrounding Alpine area, but also to better understand systematics of collisional magmatic systems.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2019.1597677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43982680","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 : 2018-01-01DOI: 10.1080/09853111.2018.1442609
Santanu Banerjee, S. Khanolkar, P. Saraswati
Abstract Middle Eocene Fulra Limestone and Oligocene Maniyara Fort Formation represent platform carbonate deposits of Kutch at the north-western margin of India. These carbonates contain larger benthic foraminifera, including Alveolina, Assilina, Discocyclina, Lepidocyclina, Miogypsina, Nummulites and Spiroclypeus. This study presents paleodepositional and paleobathymetric interpretations for both formations using benthic foraminifera in combination with lithological association, sedimentary structures and early diagenetic features. The six carbonate facies comprising the Fulra Limestone indicate a depositional spectrum ranging from bar-lagoon to mid-ramp depositional conditions. It records several shallowing upward cycles, leading to emergence and formation of paleokarst. The four carbonate facies of the Maniyara Fort Formation represents deposition within the inner ramp setting in bar-lagoon and patch-reef environment, while intervening fine siliciclastics correspond to episodes of relative sea level fall. Nummulitic accumulations form low-relief bars within the fair weather wave base in both the formations. The depositional setting of the Paleogene carbonate in Kutch broadly resembles Eocene platformal deposits in the circum-Tethys belt.
{"title":"Facies and depositional settings of the Middle Eocene-Oligocene carbonates in Kutch","authors":"Santanu Banerjee, S. Khanolkar, P. Saraswati","doi":"10.1080/09853111.2018.1442609","DOIUrl":"https://doi.org/10.1080/09853111.2018.1442609","url":null,"abstract":"Abstract Middle Eocene Fulra Limestone and Oligocene Maniyara Fort Formation represent platform carbonate deposits of Kutch at the north-western margin of India. These carbonates contain larger benthic foraminifera, including Alveolina, Assilina, Discocyclina, Lepidocyclina, Miogypsina, Nummulites and Spiroclypeus. This study presents paleodepositional and paleobathymetric interpretations for both formations using benthic foraminifera in combination with lithological association, sedimentary structures and early diagenetic features. The six carbonate facies comprising the Fulra Limestone indicate a depositional spectrum ranging from bar-lagoon to mid-ramp depositional conditions. It records several shallowing upward cycles, leading to emergence and formation of paleokarst. The four carbonate facies of the Maniyara Fort Formation represents deposition within the inner ramp setting in bar-lagoon and patch-reef environment, while intervening fine siliciclastics correspond to episodes of relative sea level fall. Nummulitic accumulations form low-relief bars within the fair weather wave base in both the formations. The depositional setting of the Paleogene carbonate in Kutch broadly resembles Eocene platformal deposits in the circum-Tethys belt.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2018.1442609","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44267715","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 : 2018-01-01DOI: 10.1080/09853111.2018.1475447
S. C. Ülgen, Nalan Lom, G. Sunal, A. Gerdes, A. Şengör
ABSTRACT Spatially continuous rock assemblages that share similar environmental evolution or structural features can be classified as a single tectonic unit. This approach enables to link dispersed units or massifs with each other and sometimes can be subjective, depending on the classification criteria. The relationship and the nature of the contact between the Strandja Massif and the İstanbul Zone have been controversial due to the Cainozoic cover. Amalgamation of these units was claimed as early as the Aptian-Albian. Lower Triassic sedimentary rocks, which are overlain by the Carboniferous flysch with a N-verging thrust fault are exposed NW of the İstanbul Zone. This study reveals the spatial relationship between the Strandja Massif and the İstanbul Zone deduced from the U-Pb dating and Lu-Hf isotopes of the detrital zircons from these Lower Triassic clastics. Our results show that the early Triassic basin was fed from a provenance that included arc-related Upper Carboniferous-Lower Permian magmatic rocks which is much more likely to be the Strandja Massif than the İstanbul Zone. The second outcome of this study is that a unit that previously assigned to Palaeozoic turned out to be Triassic, which brings the Strandja Massif farther to the east, into the northern İstanbul Zone.
{"title":"The Strandja Massif and the İstanbul Zone were once parts of the same palaeotectonic unit: new data from Triassic detrital zircons","authors":"S. C. Ülgen, Nalan Lom, G. Sunal, A. Gerdes, A. Şengör","doi":"10.1080/09853111.2018.1475447","DOIUrl":"https://doi.org/10.1080/09853111.2018.1475447","url":null,"abstract":"ABSTRACT Spatially continuous rock assemblages that share similar environmental evolution or structural features can be classified as a single tectonic unit. This approach enables to link dispersed units or massifs with each other and sometimes can be subjective, depending on the classification criteria. The relationship and the nature of the contact between the Strandja Massif and the İstanbul Zone have been controversial due to the Cainozoic cover. Amalgamation of these units was claimed as early as the Aptian-Albian. Lower Triassic sedimentary rocks, which are overlain by the Carboniferous flysch with a N-verging thrust fault are exposed NW of the İstanbul Zone. This study reveals the spatial relationship between the Strandja Massif and the İstanbul Zone deduced from the U-Pb dating and Lu-Hf isotopes of the detrital zircons from these Lower Triassic clastics. Our results show that the early Triassic basin was fed from a provenance that included arc-related Upper Carboniferous-Lower Permian magmatic rocks which is much more likely to be the Strandja Massif than the İstanbul Zone. The second outcome of this study is that a unit that previously assigned to Palaeozoic turned out to be Triassic, which brings the Strandja Massif farther to the east, into the northern İstanbul Zone.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2018.1475447","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46940881","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 : 2018-01-01DOI: 10.1080/09853111.2018.1493879
M. Martín-Martín, F. Guerrera, T. Rodríguez-Estrella, F. Serrano, F. Alcalá, G. Raffaelli, M. Tramontana
ABSTRACT An interdisciplinary study of Miocene successions in the eastern External Betic Zone (South Iberian Margin) was carried out. Evidences of syn-sedimentary tectonic activity were recognized. The results enabled a better reconstruction of the stratigraphic architecture (with an improved chronostratigraphic resolution) in the framework of the Miocene foredeep evolution of the eastern EBZ. Two main depositional sequences were dated as uppermost Burdigalian-upper Serravallian p.p. and middle-upper Tortonian. p.p., respectively. The vertical and lateral diversification of lithofacies associations and thicknesses resulted from the syn-depositional tectonic complexity of the area. A great variety of sedimentary depositional realms is due to different subsidence rates, and the growing of anticlines and synclines during the Langhian p.p.-Serravallian. After a regression with an early Tortonian erosional gap, platform to hemipelagic realms developed during the middle Tortonian. The end of the sedimentation coincided with the emplacement of an important olisthostrome-like mass consisting of Triassic material related to either the development of thrust systems or diapirs emerged in the middle-late Tortonian, during the nappe emplacement. Correlations with other external sectors of the Betic Chain, and the external domains of the Rif, Tell, and northern Apennine Chains highlighted a similar Miocene foredeep evolution during the building of these orogens.
{"title":"Miocene tectono-sedimentary evolution of the eastern external Betic Cordillera (Spain)","authors":"M. Martín-Martín, F. Guerrera, T. Rodríguez-Estrella, F. Serrano, F. Alcalá, G. Raffaelli, M. Tramontana","doi":"10.1080/09853111.2018.1493879","DOIUrl":"https://doi.org/10.1080/09853111.2018.1493879","url":null,"abstract":"ABSTRACT An interdisciplinary study of Miocene successions in the eastern External Betic Zone (South Iberian Margin) was carried out. Evidences of syn-sedimentary tectonic activity were recognized. The results enabled a better reconstruction of the stratigraphic architecture (with an improved chronostratigraphic resolution) in the framework of the Miocene foredeep evolution of the eastern EBZ. Two main depositional sequences were dated as uppermost Burdigalian-upper Serravallian p.p. and middle-upper Tortonian. p.p., respectively. The vertical and lateral diversification of lithofacies associations and thicknesses resulted from the syn-depositional tectonic complexity of the area. A great variety of sedimentary depositional realms is due to different subsidence rates, and the growing of anticlines and synclines during the Langhian p.p.-Serravallian. After a regression with an early Tortonian erosional gap, platform to hemipelagic realms developed during the middle Tortonian. The end of the sedimentation coincided with the emplacement of an important olisthostrome-like mass consisting of Triassic material related to either the development of thrust systems or diapirs emerged in the middle-late Tortonian, during the nappe emplacement. Correlations with other external sectors of the Betic Chain, and the external domains of the Rif, Tell, and northern Apennine Chains highlighted a similar Miocene foredeep evolution during the building of these orogens.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2018.1493879","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46996190","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 : 2018-01-01DOI: 10.1080/09853111.2017.1419676
N. Ali, E. Özcan, A. O. Yücel, M. Hanif, S. I. Hashmi, F. Ullah, Muhammad Rizwan, J. Pignatti
Abstract The Pirkoh and Drazinda formations in the Sulaiman Range, central Pakistan, yielded assemblages of (early) Bartonian orthophragminids, characterized predominantly by discocyclinids with a significant number of species probably endemic to Indian Subcontinent. The rarity of Asterocyclina and the absence of Orbitoclypeus and Nemkovella are noteworthy. Ten species of Discocyclina Gümbel and two species of Asterocyclina Gümbel, referable to the Shallow Benthics Zone (SBZ) 17 are described for the first time from Pakistan. The discocyclinids, i.e. Discocyclina praeomphalus, D. sulaimanensis, D. kutchensis, along with the new taxa established here, D. zindapirensis sp. nov., D. rakhinalaensis sp. nov., and D. pseudodispansa sp. nov., seem to be confined to the Indo-Pakistani region (Eastern Tethys). The Discocyclina dispansa, D. discus, D. nandori, and D. augustae lineages known from Western Tethys are also common in the Indian Subcontinent, as are asterocyclinids, such as Asterocyclina sireli and A. stellata. The upper part of the Drazinda Formation (‘Pellatispira beds’), referable to latest Bartonian and/or the early Priabonian, is poor in orthophragminids and is characterized by the occurrence of reticulate Nummulites, Heterostegina, Pellatispira and Silvestriella. The records of ‘Lepidocyclina of Caribbean affinity’ with large embryons from the Eocene of the Indian Subcontinent correspond to misidentified Discocyclina discus.
{"title":"Bartonian orthophragminids with new endemic species from the Pirkoh and Drazinda formations in the Sulaiman Range, Indus Basin, Pakistan","authors":"N. Ali, E. Özcan, A. O. Yücel, M. Hanif, S. I. Hashmi, F. Ullah, Muhammad Rizwan, J. Pignatti","doi":"10.1080/09853111.2017.1419676","DOIUrl":"https://doi.org/10.1080/09853111.2017.1419676","url":null,"abstract":"Abstract The Pirkoh and Drazinda formations in the Sulaiman Range, central Pakistan, yielded assemblages of (early) Bartonian orthophragminids, characterized predominantly by discocyclinids with a significant number of species probably endemic to Indian Subcontinent. The rarity of Asterocyclina and the absence of Orbitoclypeus and Nemkovella are noteworthy. Ten species of Discocyclina Gümbel and two species of Asterocyclina Gümbel, referable to the Shallow Benthics Zone (SBZ) 17 are described for the first time from Pakistan. The discocyclinids, i.e. Discocyclina praeomphalus, D. sulaimanensis, D. kutchensis, along with the new taxa established here, D. zindapirensis sp. nov., D. rakhinalaensis sp. nov., and D. pseudodispansa sp. nov., seem to be confined to the Indo-Pakistani region (Eastern Tethys). The Discocyclina dispansa, D. discus, D. nandori, and D. augustae lineages known from Western Tethys are also common in the Indian Subcontinent, as are asterocyclinids, such as Asterocyclina sireli and A. stellata. The upper part of the Drazinda Formation (‘Pellatispira beds’), referable to latest Bartonian and/or the early Priabonian, is poor in orthophragminids and is characterized by the occurrence of reticulate Nummulites, Heterostegina, Pellatispira and Silvestriella. The records of ‘Lepidocyclina of Caribbean affinity’ with large embryons from the Eocene of the Indian Subcontinent correspond to misidentified Discocyclina discus.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2017.1419676","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45313925","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 : 2018-01-01DOI: 10.1080/09853111.2018.1494776
Mustafa Softa, Tahir Emre, H. Sözbilir, J. Spencer, M. Turan
ABSTRACT The Eastern Pontides (EP), which is the under transpressional deformation zone, is an active mountain belt that has been rising rapidly since the Cenozoic era because of the Arabian-Eurasian convergence. Morphometric studies have been performed to investigate the tectonic activity of this region and better understand the characteristics of the faults geomorphologically; the faults control the mountain fronts in the drainage basin of the EP. The results show the Hypsometric Curve (HC)-Hypsometric Integral (0.37-HI-0.67), Basin-Shaped Analysis (1.2-Bs-7), Valley-Floor-Width to Height-Ratio (0.4-Vf-1.2) and Asymmetry Factor (35-AF-81) applied to 46 drainage basins together with 9 tectonically controlled geomorphic indices (1.2-Smf-1.5) and a Stream Length Gradient (30-SL-120) indicate that the EP is tectonically active, and when the areas are evaluated according to Smf and Vf analyses, the tectonic level is relatively high. According to our conceptual model for the uplifting of the EP, with respect to field studies and morphometric analysis, (i) the EP is the active deformation zone and has a “push-up” geometry in conjunction with the North Anatolian Fault; (ii) the EP is progressively uplifting at a rate of more than 0.5 mm/yr in along with the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF).
{"title":"Geomorphic evidence for active tectonic deformation in the coastal part of Eastern Black Sea, Eastern Pontides, Turkey","authors":"Mustafa Softa, Tahir Emre, H. Sözbilir, J. Spencer, M. Turan","doi":"10.1080/09853111.2018.1494776","DOIUrl":"https://doi.org/10.1080/09853111.2018.1494776","url":null,"abstract":"ABSTRACT The Eastern Pontides (EP), which is the under transpressional deformation zone, is an active mountain belt that has been rising rapidly since the Cenozoic era because of the Arabian-Eurasian convergence. Morphometric studies have been performed to investigate the tectonic activity of this region and better understand the characteristics of the faults geomorphologically; the faults control the mountain fronts in the drainage basin of the EP. The results show the Hypsometric Curve (HC)-Hypsometric Integral (0.37-HI-0.67), Basin-Shaped Analysis (1.2-Bs-7), Valley-Floor-Width to Height-Ratio (0.4-Vf-1.2) and Asymmetry Factor (35-AF-81) applied to 46 drainage basins together with 9 tectonically controlled geomorphic indices (1.2-Smf-1.5) and a Stream Length Gradient (30-SL-120) indicate that the EP is tectonically active, and when the areas are evaluated according to Smf and Vf analyses, the tectonic level is relatively high. According to our conceptual model for the uplifting of the EP, with respect to field studies and morphometric analysis, (i) the EP is the active deformation zone and has a “push-up” geometry in conjunction with the North Anatolian Fault; (ii) the EP is progressively uplifting at a rate of more than 0.5 mm/yr in along with the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF).","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2018.1494776","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41278900","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 : 2018-01-01DOI: 10.1080/09853111.2017.1408263
P. Saraswati, S. Khanolkar, Santanu Banerjee
Abstract The Paleogene sections of Kutch are the reference for the regional chronostratigraphic units of India. The ages of these dominantly shallow marine carbonates are mainly based on larger benthic foraminifera (LBF). The taxonomic revisions of the LBF and the progressively refined shallow benthic zonations (SBZ) have necessitated the present study on updating the stratigraphy of the area. The sedimentation in Kutch commenced with the deposition of volcaniclastics in terrestrial environments in the Paleocene. The marine transgression in SBZ 5/6 deposited finer clastics and carbonates, designated as Naredi Formation, in early Eocene. There is no evidence of marine Paleocene in Kutch. A major hiatus spanning SBZ 12 to SBZ 16 was followed by the development of a carbonate platform and deposition of Harudi Formation – Fulra Limestone during the Bartonian, SBZ 17. The hiatus corresponds to a widespread stratigraphic break in Pakistan and India to Australia, referred as the ‘Lutetian Gap.’ The Maniyara Fort Formation is assigned to SBZ 22 B and SBZ 23, and its age is revised to Chattian. Climate played a major role in building up of the Paleogene stratigraphic succession of Kutch, the carbonates formed during the warming intervals and the stratigraphic gaps were in the intervening cooling periods.
{"title":"Paleogene stratigraphy of Kutch, India: an update about progress in foraminiferal biostratigraphy","authors":"P. Saraswati, S. Khanolkar, Santanu Banerjee","doi":"10.1080/09853111.2017.1408263","DOIUrl":"https://doi.org/10.1080/09853111.2017.1408263","url":null,"abstract":"Abstract The Paleogene sections of Kutch are the reference for the regional chronostratigraphic units of India. The ages of these dominantly shallow marine carbonates are mainly based on larger benthic foraminifera (LBF). The taxonomic revisions of the LBF and the progressively refined shallow benthic zonations (SBZ) have necessitated the present study on updating the stratigraphy of the area. The sedimentation in Kutch commenced with the deposition of volcaniclastics in terrestrial environments in the Paleocene. The marine transgression in SBZ 5/6 deposited finer clastics and carbonates, designated as Naredi Formation, in early Eocene. There is no evidence of marine Paleocene in Kutch. A major hiatus spanning SBZ 12 to SBZ 16 was followed by the development of a carbonate platform and deposition of Harudi Formation – Fulra Limestone during the Bartonian, SBZ 17. The hiatus corresponds to a widespread stratigraphic break in Pakistan and India to Australia, referred as the ‘Lutetian Gap.’ The Maniyara Fort Formation is assigned to SBZ 22 B and SBZ 23, and its age is revised to Chattian. Climate played a major role in building up of the Paleogene stratigraphic succession of Kutch, the carbonates formed during the warming intervals and the stratigraphic gaps were in the intervening cooling periods.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2017.1408263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48983110","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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