Pub Date : 2013-12-01DOI: 10.1080/09853111.2013.858942
N. Bonev, Maria Ovtcharova-Schaltegger, R. Moritz, P. Marchev, A. Ulianov
Field, geochemical, and geochronologic data of high-grade basement metamafic and evolved rocks are used to identify the nature and timing of pre-Alpine crustal growth of the Rhodope Massif. These rocks occur intrusive into clastic-carbonate metasedimentary succession. Petrography and mineral chemistry show compositions consistent with Alpine amphibolite-facies metamorphism that obliterated the original igneous textures of the protoliths. Bulk-rock geochemistry identifies low-Ti tholeiitic to calc-alkaline gabbroic-basaltic and plagiogranite precursors, with MORB-IAT supra-subduction zone signature and trace elements comparable to modern back-arc basalts. The U-Pb zircon dating revealed a mean age of 455 Ma for the magmatic crystallization of the protoliths that contain inherited Cambrian (528–534 Ma) zircons. Carboniferous, Jurassic, and Eocene metamorphic events overprinted the Ordovician protoliths. The radiometric results of the metamorphic rocks demonstrate that Ordovician oceanic crust was involved in the build-up of the Rhodope high-grade basement. Dating of Eocene-Oligocene volcanic rocks overlying or cross-cutting the metamorphic rocks supplied Neoproterozoic, Ordovician and Permo-Carboniferous xenocrystic zircons that were sampled en route to the surface from the basement. The volcanic rocks thus confirm sub-regionally present Neoproterozoic and Paleozoic igneous and metamorphic basement. We interpret the origin of the Middle-Late Ordovician oceanic magmatism in a back-arc rift-spreading center propagating along peri-Gondwanan Cadomian basement terrane related to the Rheic Ocean widening. The results highlight the presence of elements of Cadomian northern Gondwana margin in the high-grade basement and record of Rheic Ocean evolution. The eastern Rhodope Massif high-grade basement compared to adjacent terranes with Neoproterozoic and Cambro-Ordovician evolution shares analogous tectono-magmatic record providing a linkage among basement terranes incorporated in the Alpine belt of the north Aegean region.
{"title":"Peri-Gondwanan Ordovician crustal fragments in the high-grade basement of the Eastern Rhodope Massif, Bulgaria: evidence from U-Pb LA-ICP-MS zircon geochronology and geochemistry","authors":"N. Bonev, Maria Ovtcharova-Schaltegger, R. Moritz, P. Marchev, A. Ulianov","doi":"10.1080/09853111.2013.858942","DOIUrl":"https://doi.org/10.1080/09853111.2013.858942","url":null,"abstract":"Field, geochemical, and geochronologic data of high-grade basement metamafic and evolved rocks are used to identify the nature and timing of pre-Alpine crustal growth of the Rhodope Massif. These rocks occur intrusive into clastic-carbonate metasedimentary succession. Petrography and mineral chemistry show compositions consistent with Alpine amphibolite-facies metamorphism that obliterated the original igneous textures of the protoliths. Bulk-rock geochemistry identifies low-Ti tholeiitic to calc-alkaline gabbroic-basaltic and plagiogranite precursors, with MORB-IAT supra-subduction zone signature and trace elements comparable to modern back-arc basalts. The U-Pb zircon dating revealed a mean age of 455 Ma for the magmatic crystallization of the protoliths that contain inherited Cambrian (528–534 Ma) zircons. Carboniferous, Jurassic, and Eocene metamorphic events overprinted the Ordovician protoliths. The radiometric results of the metamorphic rocks demonstrate that Ordovician oceanic crust was involved in the build-up of the Rhodope high-grade basement. Dating of Eocene-Oligocene volcanic rocks overlying or cross-cutting the metamorphic rocks supplied Neoproterozoic, Ordovician and Permo-Carboniferous xenocrystic zircons that were sampled en route to the surface from the basement. The volcanic rocks thus confirm sub-regionally present Neoproterozoic and Paleozoic igneous and metamorphic basement. We interpret the origin of the Middle-Late Ordovician oceanic magmatism in a back-arc rift-spreading center propagating along peri-Gondwanan Cadomian basement terrane related to the Rheic Ocean widening. The results highlight the presence of elements of Cadomian northern Gondwana margin in the high-grade basement and record of Rheic Ocean evolution. The eastern Rhodope Massif high-grade basement compared to adjacent terranes with Neoproterozoic and Cambro-Ordovician evolution shares analogous tectono-magmatic record providing a linkage among basement terranes incorporated in the Alpine belt of the north Aegean region.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858942","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59551828","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 : 2013-06-01DOI: 10.1080/09853111.2013.877237
Mine Sezgül Kayseri‐Özer
The continental climatic evolution of Anatolia has been reconstructed quantitatively for the last 45 million years using the coexistence approach. Although there were some regional effects, the Anatolian Cenozoic continental climate record correlated with the European climatic condition and the global oxygen isotope record from marine environments. From middle Eocene to late Miocene, continental warming in Anatolia was pronounced for inferred winter temperature and mean annual temperature as in Europe. Generally, the palaeoclimatic property of Anatolia resembles the European climatic changing and marine temperature changing based on the oxygen isotope record; however, climatic values of the terrestrial area in Anatolia are higher from Lutetian to Aquitanian and these values are lower than European values from Aquitanian to Tortonian. Correspondingly, Cenozoic climatic cooling in Anatolia is directly associated with an increase of seasonality, palaeogeographic position and terrestrial condition. Furthermore, mean annual precipitation values of Anatolia remained relatively stable during the Eocene–Oligocene; however, these values indicated changing throughout middle–late Miocene. Moreover, in this study, decline of abundance and variables for the mangrove and back mangrove palaeocommunities during the last 45 million years is recorded because of the decreasing of humidity, temperature and increasing of terrestrial condition.
{"title":"Spatial distribution of climatic conditions from the Middle Eocene to Late Miocene based on palynoflora in Central, Eastern and Western Anatolia","authors":"Mine Sezgül Kayseri‐Özer","doi":"10.1080/09853111.2013.877237","DOIUrl":"https://doi.org/10.1080/09853111.2013.877237","url":null,"abstract":"The continental climatic evolution of Anatolia has been reconstructed quantitatively for the last 45 million years using the coexistence approach. Although there were some regional effects, the Anatolian Cenozoic continental climate record correlated with the European climatic condition and the global oxygen isotope record from marine environments. From middle Eocene to late Miocene, continental warming in Anatolia was pronounced for inferred winter temperature and mean annual temperature as in Europe. Generally, the palaeoclimatic property of Anatolia resembles the European climatic changing and marine temperature changing based on the oxygen isotope record; however, climatic values of the terrestrial area in Anatolia are higher from Lutetian to Aquitanian and these values are lower than European values from Aquitanian to Tortonian. Correspondingly, Cenozoic climatic cooling in Anatolia is directly associated with an increase of seasonality, palaeogeographic position and terrestrial condition. Furthermore, mean annual precipitation values of Anatolia remained relatively stable during the Eocene–Oligocene; however, these values indicated changing throughout middle–late Miocene. Moreover, in this study, decline of abundance and variables for the mangrove and back mangrove palaeocommunities during the last 45 million years is recorded because of the decreasing of humidity, temperature and increasing of terrestrial condition.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.877237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552927","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 : 2013-06-01DOI: 10.1080/09853111.2013.859346
N. Görür, Şebnem Elbek
Several basins are nested on top of one another in the Marmara Region as a result of complex series of tectonic processes. These processes are related to the evolution of the Thrace Basin, North Anatolian Shear Zone and the Sea of Marmara. The Thrace Basin evolved during the early to medial Eocene (Lutetian) as a forearc basin above the northward subducting Intra-Pontide Ocean. The basin was largely deformed and eroded during the Lutetian when the Intra-Pontide Ocean closed. Following this closure, the basin turned into a remnant forearc and continued accumulating sediments with calc-alkalic volcanic rocks. When the subducting slab finally detached and fell at the end of the Oligocene, it underwent a basin-wide deformation and erosion in the early Miocene. From medial Miocene onward, a dextral shear zone superimposed the Thrace Basin. Evolution of the shear zone began in the medial Miocene and still continues with various tectonic structures, representing the pre-peak, peak, post-peak and pre-residual stages. The Sea of Marmara probably formed during the Pliocene to Pleistocene along a variety of Riedel and P-shears of the post-peak and pre-residual structure stages.
{"title":"Tectonic events responsible for shaping the Sea of Marmara and its surrounding region","authors":"N. Görür, Şebnem Elbek","doi":"10.1080/09853111.2013.859346","DOIUrl":"https://doi.org/10.1080/09853111.2013.859346","url":null,"abstract":"Several basins are nested on top of one another in the Marmara Region as a result of complex series of tectonic processes. These processes are related to the evolution of the Thrace Basin, North Anatolian Shear Zone and the Sea of Marmara. The Thrace Basin evolved during the early to medial Eocene (Lutetian) as a forearc basin above the northward subducting Intra-Pontide Ocean. The basin was largely deformed and eroded during the Lutetian when the Intra-Pontide Ocean closed. Following this closure, the basin turned into a remnant forearc and continued accumulating sediments with calc-alkalic volcanic rocks. When the subducting slab finally detached and fell at the end of the Oligocene, it underwent a basin-wide deformation and erosion in the early Miocene. From medial Miocene onward, a dextral shear zone superimposed the Thrace Basin. Evolution of the shear zone began in the medial Miocene and still continues with various tectonic structures, representing the pre-peak, peak, post-peak and pre-residual stages. The Sea of Marmara probably formed during the Pliocene to Pleistocene along a variety of Riedel and P-shears of the post-peak and pre-residual structure stages.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.859346","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552127","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 : 2013-06-01DOI: 10.1080/09853111.2013.858944
M. Coen-Aubert, R. Gourvennec, O. Monod, Y. Plusquellec, F. Tourneur
A section near the Kilgen Lake (Adana Province) has yielded a fauna of rugose and tabulate corals including Disphyllum cf. rugosum (Wedekind, 1922), D. cf. curtum Hill, 1954, Wapitiphyllum sp., Thamnopora sp., and Alveolites sp. This coral assemblage is consistent with the previous Frasnian age assigned to the limestones of the Gümüşali Formation. The rather well-preserved material provides new data on the structure and microstructure of Disphyllum and allows to describe in Thamnopora unusual calicinal morphology (septal ridges, median teeth, and pseudopercula) as well as new structures linked to the lateral increase (basal low wall, apical cul-de-sac).
在Kilgen湖(Adana省)附近的一段区域发现了一组斑状珊瑚和表状珊瑚，包括Disphyllum cf. rugosum (Wedekind, 1922)， D. cf. curtum Hill, 1954, Wapitiphyllum sp.， Thamnopora sp.和Alveolites sp.。这种珊瑚组合与先前分配给g m ali组石灰石的Frasnian年龄一致。这些保存相当完好的材料提供了关于双叶门的结构和微观结构的新数据，并允许描述在Thamnopora中不寻常的边缘形态(间隔脊，中齿和假包皮)以及与外侧增加相关的新结构(基部低壁，顶端死囊)。
{"title":"Frasnian rugose and tabulate corals from the eastern Taurus (Kozan region, Turkey)","authors":"M. Coen-Aubert, R. Gourvennec, O. Monod, Y. Plusquellec, F. Tourneur","doi":"10.1080/09853111.2013.858944","DOIUrl":"https://doi.org/10.1080/09853111.2013.858944","url":null,"abstract":"A section near the Kilgen Lake (Adana Province) has yielded a fauna of rugose and tabulate corals including Disphyllum cf. rugosum (Wedekind, 1922), D. cf. curtum Hill, 1954, Wapitiphyllum sp., Thamnopora sp., and Alveolites sp. This coral assemblage is consistent with the previous Frasnian age assigned to the limestones of the Gümüşali Formation. The rather well-preserved material provides new data on the structure and microstructure of Disphyllum and allows to describe in Thamnopora unusual calicinal morphology (septal ridges, median teeth, and pseudopercula) as well as new structures linked to the lateral increase (basal low wall, apical cul-de-sac).","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858944","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59551931","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 : 2013-06-01DOI: 10.1080/09853111.2013.858943
W. Cavazza, L. Caracciolo, S. Critelli, A. d’Atri, G. Zuffa
Eocene-Oligocene paleogeographic/paleotectonic reconstructions of the Rhodopian – northern Aegean – western Black Sea region largely ignore the Thrace Basin, a large sedimentary basin up to 9 km thick that has been long interpreted as a forearc basin developed in a context of northward subduction. Recent structural, stratigraphic, petrologic, and sedimentologic data challenge this notion and may instead be interpreted within a context of upper-plate extension during the complex transition between the collisional tectonic regime related to the closure of Vardar-İzmir-Ankara oceanic realm and the extensional regime characterizing the Oligocene-Neogene evolution of the Aegean and peri-Aegean regions. The detritus filling the Thrace Basin was derived from two main sediment source areas: (i) the mostly metamorphic terrains of the Rhodopes to the west and (ii) the Vardar-İzmir-Ankara and Biga (intra-Pontide?) subduction-accretion prisms to the southwest. During most of the Eocene-Oligocene, the entire basin was characterized by a complex physiography, as shown by commercial seismic lines in the subsurface and abrupt lateral facies change at the surface. Such physiography was controlled by a series of basement highs trending from WNW-ESE (in the eastern and northern portions of the basin) to WSW-ENE (in the western and southern portions of the basin) which influenced sediment dispersal and the areal distribution of paleoenvironments.
{"title":"Petrostratigraphic evolution of the Thrace Basin (Bulgaria, Greece, Turkey) within the context of Eocene-Oligocene post-collisional evolution of the Vardar-İzmir-Ankara suture zone","authors":"W. Cavazza, L. Caracciolo, S. Critelli, A. d’Atri, G. Zuffa","doi":"10.1080/09853111.2013.858943","DOIUrl":"https://doi.org/10.1080/09853111.2013.858943","url":null,"abstract":"Eocene-Oligocene paleogeographic/paleotectonic reconstructions of the Rhodopian – northern Aegean – western Black Sea region largely ignore the Thrace Basin, a large sedimentary basin up to 9 km thick that has been long interpreted as a forearc basin developed in a context of northward subduction. Recent structural, stratigraphic, petrologic, and sedimentologic data challenge this notion and may instead be interpreted within a context of upper-plate extension during the complex transition between the collisional tectonic regime related to the closure of Vardar-İzmir-Ankara oceanic realm and the extensional regime characterizing the Oligocene-Neogene evolution of the Aegean and peri-Aegean regions. The detritus filling the Thrace Basin was derived from two main sediment source areas: (i) the mostly metamorphic terrains of the Rhodopes to the west and (ii) the Vardar-İzmir-Ankara and Biga (intra-Pontide?) subduction-accretion prisms to the southwest. During most of the Eocene-Oligocene, the entire basin was characterized by a complex physiography, as shown by commercial seismic lines in the subsurface and abrupt lateral facies change at the surface. Such physiography was controlled by a series of basement highs trending from WNW-ESE (in the eastern and northern portions of the basin) to WSW-ENE (in the western and southern portions of the basin) which influenced sediment dispersal and the areal distribution of paleoenvironments.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858943","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59551875","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 : 2013-06-01DOI: 10.1080/09853111.2013.877238
P. Moix, Š. Goričan
Two large blocks of red bedded chert identified within the Late Cretaceous–Paleocene Bornova mélange in northern Karaburun Peninsula yielded Jurassic (late Bathonian–early Oxfordian) and Cretaceous (middle–late Albian) radiolarian assemblages. These new data confirm the correlation of the Bornova mélange with the Bornova Flysch Zone (BFZ) and the İzmir–Ankara mélanges. A review of all previously obtained ages in chert blocks of the BFZ and the İzmir–Ankara mélanges is provided in order to strengthen this correlation.
{"title":"Jurassic and Cretaceous radiolarian assemblages from the Bornova mélange in northern Karaburun Peninsula (western Turkey) and its connection to the İzmir–Ankara mélanges","authors":"P. Moix, Š. Goričan","doi":"10.1080/09853111.2013.877238","DOIUrl":"https://doi.org/10.1080/09853111.2013.877238","url":null,"abstract":"Two large blocks of red bedded chert identified within the Late Cretaceous–Paleocene Bornova mélange in northern Karaburun Peninsula yielded Jurassic (late Bathonian–early Oxfordian) and Cretaceous (middle–late Albian) radiolarian assemblages. These new data confirm the correlation of the Bornova mélange with the Bornova Flysch Zone (BFZ) and the İzmir–Ankara mélanges. A review of all previously obtained ages in chert blocks of the BFZ and the İzmir–Ankara mélanges is provided in order to strengthen this correlation.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.877238","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552573","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 : 2013-06-01DOI: 10.1080/09853111.2013.858950
Kmar Ben İsmail-Lattrache, E. Özcan, K. Boukhalfa, P. Saraswati, M. Soussi, L. Jovane
The orthophragminids in lower Bartonian Reineche Limestone member, a fossiliferous shallow-marine unit exposed in Cap Bon peninsula in Tunisia, are represented by 17 species assigned to Discocyclinidae Galloway 1928 and Orbitoclypeidae Brönnimann 1946. These taxa, associated with nummulitids and alveolinids, belong to the lineages of Discocyclina Gümbel 1870, Nemkovella, 1987, Orbitoclypeus Silvestri 1907, and Asterocyclina Gümbel 1870, described for the first time from north Africa lying at the southern margin of Tethyan ocean during Paleogene. We identified Nemkovella evae, previously not recorded in upper Lutetian/lower Bartonian and younger Eocene deposits of northern Tethyan platforms, and erected a new subspecies, N. evae reinechensis n. ssp. A comparison of Reineche orthophraminids, assigned to orthophragmines zone (OZ) 12 and shallow benthic zone (SBZ 17), to the well-described coeval assemblages at northern Tethyan platforms in Italy, Hungary, Turkey, and to those in Kutch Basin in the Indian subcontinent suggests that some species are confined to certain paleogeographic domains. Orbitoclypeus haynesi, the only orbitoclypeid and the most abundant orthophragminid in lower Bartonian deposits in Kutch, appears to be the most common orbitoclypeid in Reineche Limestone. In Europe, this species is not known and is replaced by Orbitoclypeus varians, the most common orbitoclypeid in middle Eocene of central Europe. Both species occur in varying proportions in marine successions in Turkey. Asterocyclina sireli, identified so far only in Turkey, occurs in Reineche Limestone and in lower Bartonian deposits in Kutch. This species is recorded for the first time in the Indian subcontinent. Relying on present study, as well as our recent studies in Kutch Basin, we conclude that the generic and specific diversity of orthophragminids decreases eastward from the peri-Mediterranean region to Indian subcontinent and to the western Pacific.
下Bartonian Reineche石灰岩段的orthophragminids是在突尼斯Cap Bon半岛发现的一个浅海化石单元，有17种，归属于Discocyclinidae Galloway 1928和Orbitoclypeidae Brönnimann 1946。这些分类群与nummultiids和alveolinids有关联，属于Discocyclina g mbel 1870、Nemkovella(1987)、Orbitoclypeus Silvestri 1907和Asterocyclina g mbel 1870的谱系，这些谱系在古近纪时期首次在特提斯洋南缘的北非被发现。我们鉴定了在特提斯北部台地上卢特世/下巴尔顿世和始新世早期沉积中未发现的Nemkovella evae，并建立了一个新的亚种:Nemkovella reinechensis N. ssp。将Reineche orthophraminids(归属于orthophramines带(OZ) 12和浅底栖带(SBZ 17))与意大利、匈牙利、土耳其北部特提斯台地和印度次大陆Kutch盆地的同类组合进行比较，表明一些物种局限于某些古地理域。haynesi是Kutch下巴尔东期沉积中唯一的眶足类，也是最丰富的正斜足类，是Reineche灰岩中最常见的眶足类。在欧洲，这一物种尚不为人所知，并被中欧始新世中期最常见的轨道鱼变种Orbitoclypeus varians所取代。这两种物种在土耳其的海洋演替中以不同的比例出现。到目前为止，仅在土耳其发现的Asterocyclina sireli出现在Reineche石灰岩和Kutch的下巴顿矿床中。该物种首次在印度次大陆被记录。根据目前的研究，以及我们最近在Kutch盆地的研究，我们得出结论，从地中海周边地区到印度次大陆和西太平洋，orthophragminids的一般和特定多样性向东减少。
{"title":"Early Bartonian orthophragminids (Foraminiferida) from Reineche Limestone, north African platform, Tunisia: taxonomy and paleobiogeographic implications","authors":"Kmar Ben İsmail-Lattrache, E. Özcan, K. Boukhalfa, P. Saraswati, M. Soussi, L. Jovane","doi":"10.1080/09853111.2013.858950","DOIUrl":"https://doi.org/10.1080/09853111.2013.858950","url":null,"abstract":"The orthophragminids in lower Bartonian Reineche Limestone member, a fossiliferous shallow-marine unit exposed in Cap Bon peninsula in Tunisia, are represented by 17 species assigned to Discocyclinidae Galloway 1928 and Orbitoclypeidae Brönnimann 1946. These taxa, associated with nummulitids and alveolinids, belong to the lineages of Discocyclina Gümbel 1870, Nemkovella, 1987, Orbitoclypeus Silvestri 1907, and Asterocyclina Gümbel 1870, described for the first time from north Africa lying at the southern margin of Tethyan ocean during Paleogene. We identified Nemkovella evae, previously not recorded in upper Lutetian/lower Bartonian and younger Eocene deposits of northern Tethyan platforms, and erected a new subspecies, N. evae reinechensis n. ssp. A comparison of Reineche orthophraminids, assigned to orthophragmines zone (OZ) 12 and shallow benthic zone (SBZ 17), to the well-described coeval assemblages at northern Tethyan platforms in Italy, Hungary, Turkey, and to those in Kutch Basin in the Indian subcontinent suggests that some species are confined to certain paleogeographic domains. Orbitoclypeus haynesi, the only orbitoclypeid and the most abundant orthophragminid in lower Bartonian deposits in Kutch, appears to be the most common orbitoclypeid in Reineche Limestone. In Europe, this species is not known and is replaced by Orbitoclypeus varians, the most common orbitoclypeid in middle Eocene of central Europe. Both species occur in varying proportions in marine successions in Turkey. Asterocyclina sireli, identified so far only in Turkey, occurs in Reineche Limestone and in lower Bartonian deposits in Kutch. This species is recorded for the first time in the Indian subcontinent. Relying on present study, as well as our recent studies in Kutch Basin, we conclude that the generic and specific diversity of orthophragminids decreases eastward from the peri-Mediterranean region to Indian subcontinent and to the western Pacific.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858950","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552262","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 : 2013-04-01DOI: 10.1080/09853111.2013.858962
O. Tüysüz, U. Tarı, Ş. Genç, C. Imren, B. Blackwell, J. Wehmiller, Darrell S. Kaufman, S. Altiok, M. Beyhan, Dominik Fleitmann, Nalan Lom, Sibel Üsküplü, Özge Tekeşin, Jonathan A. Florentin
In southeastern Turkey, the NE-trending Antakya Graben forms an asymmetric depression filled by Pliocene marine siliciclastic sediment, Pleistocene to Recent fluvial terrace sediment, and alluvium. Along the Mediterranean coast of the graben, marine terrace deposits sit at different elevations ranging from 2 to 180 m above present sea level, with ages ranging from MIS 2 to 11. A multisegmented, dominantly sinistral fault lying along the graben may connect the Cyprus Arc in the west to the Amik Triple Junction on the Dead Sea Fault (DSF) in the east. Normal faults, which are younger than the sinistral ones, bound the graben’s southeastern margin. The westward escape of the continental İskenderun Block, delimited by sinistral fault segments belonging to the DSF in the east and the Eastern Anatolian Fault in the north caused the development of a sinistral transtensional tectonic regime, which has opened the Antakya Graben since the Pliocene. In the later stages of this opening, normal faults developed along the southeastern margin that caused the graben to tilt to the southwest, leading to differential uplift of Mediterranean coastal terraces. Most of these normal faults remain active. In addition to these tectonic movements, Pleistocene sea level changes in the Mediterranean affected the geomorphological evolution of the area.
{"title":"The geology and morphology of the Antakya Graben between the Amik Triple Junction and the Cyprus Arc","authors":"O. Tüysüz, U. Tarı, Ş. Genç, C. Imren, B. Blackwell, J. Wehmiller, Darrell S. Kaufman, S. Altiok, M. Beyhan, Dominik Fleitmann, Nalan Lom, Sibel Üsküplü, Özge Tekeşin, Jonathan A. Florentin","doi":"10.1080/09853111.2013.858962","DOIUrl":"https://doi.org/10.1080/09853111.2013.858962","url":null,"abstract":"In southeastern Turkey, the NE-trending Antakya Graben forms an asymmetric depression filled by Pliocene marine siliciclastic sediment, Pleistocene to Recent fluvial terrace sediment, and alluvium. Along the Mediterranean coast of the graben, marine terrace deposits sit at different elevations ranging from 2 to 180 m above present sea level, with ages ranging from MIS 2 to 11. A multisegmented, dominantly sinistral fault lying along the graben may connect the Cyprus Arc in the west to the Amik Triple Junction on the Dead Sea Fault (DSF) in the east. Normal faults, which are younger than the sinistral ones, bound the graben’s southeastern margin. The westward escape of the continental İskenderun Block, delimited by sinistral fault segments belonging to the DSF in the east and the Eastern Anatolian Fault in the north caused the development of a sinistral transtensional tectonic regime, which has opened the Antakya Graben since the Pliocene. In the later stages of this opening, normal faults developed along the southeastern margin that caused the graben to tilt to the southwest, leading to differential uplift of Mediterranean coastal terraces. Most of these normal faults remain active. In addition to these tectonic movements, Pleistocene sea level changes in the Mediterranean affected the geomorphological evolution of the area.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2013-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858962","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552479","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: 10.1080/09853111.2013.858947
G. Sunal
The Karacabey Pluton is a large magmatic body in the northwestern Turkey overthrust by the probable Triassic metamorphic rocks of the Lower Karakaya Complex. Both the metamorphic rocks and the Karacabey Pluton are unconformably overlain by a Lower Jurassic and younger sedimentary sequence. The Karacabey Pluton was regarded as a Carboniferous intrusion based on the previous K-Ar biotite geochronological data. Here, we provide new geological, geochemical and geochronological data from the Karacabey Pluton. Zircon U-Pb results from two samples yielded ages of 393.8 +/−2.7 to 395.9 +/−4.09 Ma, suggesting that the granitoids intruded in the crust throughout the Early to Middle Devonian. The Karacabey Pluton consists mainly of biotite and locally hornblende bearing granitoid with lesser amounts of S-type leucocratic granodiorite, all of which are cut by pegmatitic bodies. It belongs to the high-K calc-alkaline series with distinct Nb and Ta anomalies in multi-element spider diagram. Sr and Nd isotopes’ initial values are 0.709–0.712 and 0.511–0.512, respectively. εNd(i) values range between −7.8 and −9.4. The isotopic characteristics of the rocks indicate lower crustal sources of both metapelitic and metaigneous origin. Geochemical features of the rocks suggest that they developed in an arc-related environment, along with the other Devonian granitoids described from the Biga Peninsula in northwest Turkey. The granitoid shows a low-temperature alteration/metamorphism marked by recrystallization of quartz, sericitization of the feldspar and formation of late chlorite, epidote and muscovite. Possibly because of these, the Ar–Ar biotite ages are scattered with a possible concentration at around Permo–Carboniferous boundary. Zircon (U-Th)/He geochronology suggests that after the granitoid was reburied during Early Jurassic to Early Cretaceous sedimentation, there was renewed uplift and erosion during the Late Cretaceous (Turonian), which is possibly related to the closure of the Intra-Pontide Ocean in the north.
{"title":"Devonian magmatism in the western Sakarya Zone, Karacabey region, NW Turkey","authors":"G. Sunal","doi":"10.1080/09853111.2013.858947","DOIUrl":"https://doi.org/10.1080/09853111.2013.858947","url":null,"abstract":"The Karacabey Pluton is a large magmatic body in the northwestern Turkey overthrust by the probable Triassic metamorphic rocks of the Lower Karakaya Complex. Both the metamorphic rocks and the Karacabey Pluton are unconformably overlain by a Lower Jurassic and younger sedimentary sequence. The Karacabey Pluton was regarded as a Carboniferous intrusion based on the previous K-Ar biotite geochronological data. Here, we provide new geological, geochemical and geochronological data from the Karacabey Pluton. Zircon U-Pb results from two samples yielded ages of 393.8 +/−2.7 to 395.9 +/−4.09 Ma, suggesting that the granitoids intruded in the crust throughout the Early to Middle Devonian. The Karacabey Pluton consists mainly of biotite and locally hornblende bearing granitoid with lesser amounts of S-type leucocratic granodiorite, all of which are cut by pegmatitic bodies. It belongs to the high-K calc-alkaline series with distinct Nb and Ta anomalies in multi-element spider diagram. Sr and Nd isotopes’ initial values are 0.709–0.712 and 0.511–0.512, respectively. εNd(i) values range between −7.8 and −9.4. The isotopic characteristics of the rocks indicate lower crustal sources of both metapelitic and metaigneous origin. Geochemical features of the rocks suggest that they developed in an arc-related environment, along with the other Devonian granitoids described from the Biga Peninsula in northwest Turkey. The granitoid shows a low-temperature alteration/metamorphism marked by recrystallization of quartz, sericitization of the feldspar and formation of late chlorite, epidote and muscovite. Possibly because of these, the Ar–Ar biotite ages are scattered with a possible concentration at around Permo–Carboniferous boundary. Zircon (U-Th)/He geochronology suggests that after the granitoid was reburied during Early Jurassic to Early Cretaceous sedimentation, there was renewed uplift and erosion during the Late Cretaceous (Turonian), which is possibly related to the closure of the Intra-Pontide Ocean in the north.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858947","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59551918","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: 10.1080/09853111.2013.858948
F. Karaoglan, O. Parlak, U. Klötzli, M. Thöni, F. Koller
The ophiolites in southeast Turkey crop out along two distinct belts. The ophiolites in the north are attached to Tauride active margin and represented by Göksun, Berit, İspendere, Kömürhan and Guleman ophiolites. Whereas the ophiolites in the south are observed as tectonically overlying the Arabian continental margin and characterized mainly by Kızıldağ (Hatay) and Koçali ophiolites. In this paper, new U–Pb and Sm–Nd isotopic ages are presented. The zircons extracted from the gabbroic cumulates of the Kömürhan ophiolite yielded a concordia age of 87.2 ± 3.1 Ma. The zircons in the gabbroic cumulates of the İspendere ophiolite yielded a Concordia age of 84.5 ± 3.9 Ma. Moreover, the Sm–Nd age of the gabbroic cumulates of the İspendere ophiolite yielded 85.1 ± 7.1 Ma (εNd = + 7.8). The gabbroic rocks of the Kızıldağ (Hatay) ophiolite yielded 110 ± 11 Ma (εNd = + 7.3) Sm–Nd isochron age. The new and already published U–Pb and Sm–Nd ages from the Kızıldağ ophiolite suggest that the time span between the melt generation in a subduction zone setting and SSZ-type oceanic crust crystallization was ≥3 my. All the ages from the Southeast Anatolian ophiolites suggest that the ophiolites between the Bitlis–Pütürge continent and the Arabian platform formed around 99–102 Ma whereas the ophiolites between the Bitlis–Pütürge continent and the Tauride platform formed around 84–90 Ma, suggesting that the peri-Arabic belt ophiolites are 10 My older than the ophiolite attached to the Malatya–Keban platform in the north. Detailed comparison suggests that there are number of differences between the ophiolites to the north and south of the Bitlis–Pütürge continental unit based on the geological, geochronological, petrological, internal stratigraphy of the ophiolites as well as their relationships with the continental fragments during the late Cretaceous. Therefore, the ophiolites were rooted from two different oceanic basins, one to the north and other to the south of the Bitlis–Pütürge continent.
土耳其东南部蛇绿岩沿两条截然不同的带出。北部蛇绿岩附属于金牛莱德活动边缘，以Göksun、Berit、İspendere、Kömürhan和Guleman蛇绿岩为代表。南方蛇绿岩构造上覆于阿拉伯大陆边缘，以Kızıldağ (Hatay)和koali蛇绿岩为主。本文给出了新的U-Pb和Sm-Nd同位素年龄。从Kömürhan蛇绿岩辉长岩中提取的锆石，其协和年龄为87.2±3.1 Ma。İspendere蛇绿岩辉长岩中锆石的Concordia年龄为84.5±3.9 Ma。İspendere蛇绿岩辉长岩的Sm-Nd年龄为85.1±7.1 Ma (εNd = + 7.8)。Kızıldağ (Hatay)蛇绿岩辉长岩的等时年龄为110±11 Ma (εNd = + 7.3)。Kızıldağ蛇绿岩的U-Pb和Sm-Nd年龄表明，俯冲带背景下熔体的产生与ssz型洋壳结晶之间的时间跨度≥3 m。东南安纳托利亚蛇绿岩的年龄表明，bitls - p tt rge大陆与阿拉伯地台之间的蛇绿岩形成于99 ~ 102 Ma，而bitls - p tt rge大陆与Tauride地台之间的蛇绿岩形成于84 ~ 90 Ma，表明近阿拉伯带蛇绿岩比北部Malatya-Keban地台的蛇绿岩年龄大10 Ma。详细比较表明，根据蛇绿岩的地质、年代学、岩石学、内部地层学以及与晚白垩世大陆碎片的关系，bitris - p ttrge大陆单元南北蛇绿岩之间存在许多差异。因此，蛇绿岩起源于两个不同的海洋盆地，一个在bitlis - p ttrge大陆的北部，另一个在南部。
{"title":"U–Pb and Sm–Nd geochronology of the ophiolites from the SE Turkey: implications for the Neotethyan evolution","authors":"F. Karaoglan, O. Parlak, U. Klötzli, M. Thöni, F. Koller","doi":"10.1080/09853111.2013.858948","DOIUrl":"https://doi.org/10.1080/09853111.2013.858948","url":null,"abstract":"The ophiolites in southeast Turkey crop out along two distinct belts. The ophiolites in the north are attached to Tauride active margin and represented by Göksun, Berit, İspendere, Kömürhan and Guleman ophiolites. Whereas the ophiolites in the south are observed as tectonically overlying the Arabian continental margin and characterized mainly by Kızıldağ (Hatay) and Koçali ophiolites. In this paper, new U–Pb and Sm–Nd isotopic ages are presented. The zircons extracted from the gabbroic cumulates of the Kömürhan ophiolite yielded a concordia age of 87.2 ± 3.1 Ma. The zircons in the gabbroic cumulates of the İspendere ophiolite yielded a Concordia age of 84.5 ± 3.9 Ma. Moreover, the Sm–Nd age of the gabbroic cumulates of the İspendere ophiolite yielded 85.1 ± 7.1 Ma (εNd = + 7.8). The gabbroic rocks of the Kızıldağ (Hatay) ophiolite yielded 110 ± 11 Ma (εNd = + 7.3) Sm–Nd isochron age. The new and already published U–Pb and Sm–Nd ages from the Kızıldağ ophiolite suggest that the time span between the melt generation in a subduction zone setting and SSZ-type oceanic crust crystallization was ≥3 my. All the ages from the Southeast Anatolian ophiolites suggest that the ophiolites between the Bitlis–Pütürge continent and the Arabian platform formed around 99–102 Ma whereas the ophiolites between the Bitlis–Pütürge continent and the Tauride platform formed around 84–90 Ma, suggesting that the peri-Arabic belt ophiolites are 10 My older than the ophiolite attached to the Malatya–Keban platform in the north. Detailed comparison suggests that there are number of differences between the ophiolites to the north and south of the Bitlis–Pütürge continental unit based on the geological, geochronological, petrological, internal stratigraphy of the ophiolites as well as their relationships with the continental fragments during the late Cretaceous. Therefore, the ophiolites were rooted from two different oceanic basins, one to the north and other to the south of the Bitlis–Pütürge continent.","PeriodicalId":50420,"journal":{"name":"Geodinamica Acta","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09853111.2013.858948","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59552000","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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