Geologica ActaPub Date : 2022-11-23DOI: 10.1344/geologicaacta2022.20.15
M. Chichorro, A. R. Solá, T. M. Bento dos Santos, João Lains Amaral, Lourenço Crispim
{"title":"Cadomian/Pan-African consolidation of the Iberian Massif assessed by its detrital and inherited zircon populations: is the ~610Ma age peak a persistent Cadomian magmatic inheritance or the key to unravel its Pan-African basement?","authors":"M. Chichorro, A. R. Solá, T. M. Bento dos Santos, João Lains Amaral, Lourenço Crispim","doi":"10.1344/geologicaacta2022.20.15","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.15","url":null,"abstract":"This work assessed the age distribution of Cadomian/Pan-African orogenic events (550-590 and 605-790Ma, respectively) in several zones of Iberian Massif by means of detrital and inherited zircon analysis compilation.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44414421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-10-21DOI: 10.1344/geologicaacta2022.20.14
M. Padel, S. Clausen, M. Poujol, Jose Javier Alvaro Blasco
{"title":"Shifts in the Ediacaran to Lower Ordovician sedimentary zircon provenances of Northwest Gondwana: the Pyrenean files","authors":"M. Padel, S. Clausen, M. Poujol, Jose Javier Alvaro Blasco","doi":"10.1344/geologicaacta2022.20.14","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.14","url":null,"abstract":"Detrital zircon grains from Cambrian–Lower Ordovician sandstones and quartzites sampled in the Pyrenees were dated by LA-ICPMS in order to assess their provenance sources. Resulting age distributions are compared to other available datasets from neighbouring margins, such as Morocco, the Iberian Peninsula, southern France and Sardinia. Kolmogorov-Smirnov (K-S) test and Crystallization Age-Depositional Age (CA-DA) diagrams were used to compare zircon populations estimating their possible correlation with the arc/rift/drift geodynamic evolution of the northwestern Gondwana margin. During Terreneuvian times, zircon populations allowed the distinction of i) a southwesternmost edge (Anti-Atlas-Ossa-Morena Rift) mostly influenced by Panafrican and Anti-Atlasian sources (ca. 0.63–0.54), ii) a northeasternmost edge (Sardinia) recording the influence of the Saharan Metacraton and the Arabian Nubian Shield, with an distinct Stenian–Tonian shift (ca. 1.25–0.85Ga) and iii) an intermediate palaeogeographic transect, where lies the Central-Iberian, West Asturian-Leonese and Cantabrian Zones, the Montagne Noire and the Pyrenees sharing similar populations and a chronologically progressive influence from Anti-Atlasian/Panafrican to Saharan Metacraton/Arabian Nubian Shield sources. This gradual modification in zircon percentage populations supports similar trends based on climatically sensitive indicators, biogeographic patterns of Cambrian Epoch 2 archaeocyathan and microfossil assemblages, and laterally correlatable episodes of carbonate production, all of them pointing to a Cambrian setting for the Pyrenean Basin between the Montagne Noire (Occitan Domain) and the Sardinian margins of NW Gondwana. The Terreneuvian zircon patterns recorded in the Pyrenees gradually evolved from Cambrian Epoch 2 to Early Ordovician times, reflecting the geodynamic evolution from Panafrican and Cadomian arc-related to rift-dominant conditions. During Furongian and Ordovician times, the relative percentage of zircon populations led to a more spread age curve, characteristic of extensional settings and pointing to rift (passive margin) conditions.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41961417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-09-23DOI: 10.1344/geologicaacta2022.20.12
Emilio L. Pueyo, A. Rodríguez-Pintó, J. Serra-Kiel, A. Barnolas
{"title":"The chronology and rotational kinematics in the South-Eastern Jaca Basin (Southern Pyrenees): Las Bellostas section","authors":"Emilio L. Pueyo, A. Rodríguez-Pintó, J. Serra-Kiel, A. Barnolas","doi":"10.1344/geologicaacta2022.20.12","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.12","url":null,"abstract":"Despite the large number of magnetostratigraphic studies in the South Pyrenean Basin aiming to calibrate the basin chronostratigraphy and the biostratigraphic scales, the South Eastern Jaca Basin remains unexplored from this perspective, and its relation with the Ainsa Basin is not fully understood. In this work we contribute with new magnetostratigraphic data from the 950m thick Las Bellostas section, located in the northern hinge of the Balzes anticline. Well-proven primary signal (positive fold test and two pseudo-antiparallel polarities) supported by numerous primary data in the surroundings allow us building a reliable local polarity sequence of eight magnetozones (from R1 to N4). Additionally, seven new biostratigraphic samples (Nummulites and Assilina) in the lower part of the section (marine environment) allows tightening the section to the Geomagnetic Polarity Time Scale (GPTS) and proposing a refined age model for the southeastern Jaca Basin. The section starts in the Boltaña Fm., of Cuisian age (Shallow Benthic Zone, SBZ11), is followed by a sedimentary gap from C22n to C20n as witnessed by biostratigraphic data (SBZ11 underneath the hiatus and SBZ16 just atop). The deltaic Sobrarbe Fm. can be tracked until the C19n (Late Lutetian). From this point (200m) until the top of the section (950m), at least, the entire C18n chron can be recognized within the molassic Campodarbe Fm. (C18n.2n-C18n.1r and C18n.1n) (Bartonian) equivalent to the West to the prodeltaic Arguis marls Fm. The Middle Cusian (SBZ11) to Middle Lutetian (SBZ15) stratigraphic hiatus is, in part, enhanced by the structural position at the hinge of the Balzes anticline. These new chronostratigraphic constraints help refining the W-E and N-S stratigraphic relationships in the eastern Jaca Basin and in the Ainsa Basin. This section also allows us to accurately refine the kinematics of the rotational activity in the eastern External Sierras. The important difference in magnetic declination along the section and neighboring paleomagnetic data from the Balzes anticline (from ≈70º clockwise at the base of the stratigraphic section to non-significant at the top) together with the new age model for the Eastern Jaca Basin help characterizing the rotational activity of the Balzes thrust sheet. The rotation took place between chrons C20r (Middle Lutetian; 45Ma) and C17 (Lower Priabonian 37-38Ma) in agreement to nearby structures (Boltaña, Picodel Aguila anticlines) but clearly diachronic to western ones (Santo Domingo anticline). Besides, the rotational activity seems to follow a linear and continuous pattern (velocity 9-11º/Ma, R: 0.83-0.96) in contrast to closer structures that show two distinct rotational velocities (i.e. Boltaña). These new data still let open the debate on the rotational kinematics along the South Pyrenean basal thrust.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49557928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-09-16DOI: 10.1344/geologicaacta2022.20.11
R. Rajani
{"title":"Geochemistry of Khandadharpahar-Thakuranipahar metabasites from the western Singhbhum Craton, eastern India: implications for subduction-zone tectonics and mantle-wedge metasomatism","authors":"R. Rajani","doi":"10.1344/geologicaacta2022.20.11","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.11","url":null,"abstract":"The identification of new rock types in the volcano-sedimentary sequences of the Singhbhum Craton has attractedmuch attention in recent years. The present study deals on newly identified Nb-Enriched Basalts (NEB) from theKhandadharpahar-Kadakala-Thakuranipahar (KKT) section, western Singhbhum Craton, which is comparablein composition to basalts-basaltic andesites and calk-alkaline in character. These metabasites have a porphyritictexture with phenocrysts of pyroxene and plagioclase, as well as a groundmass that has metamorphosed to thegreenschist facies. High Nb contents (7.5-22.8ppm) combined with high (Nb/Th)PM (0.28-0.59), (Nb/La)PM (0.40-0.69) and Nb/U (11.7-34.4) ratios, compared to arc basalts ((Nb/Th)PM= 0.10-1.19; (Nb/La)PMn 0.17-0.99, Nb/U<10), characterized them as NEB. Negative Nb, Zr, Hf and Ti anomalies, and Nb/Th vs La/Nb and Th/Nb vs. La/Sm relationships, collectively indicate typical arc volcanics. The available geochemical parameters suggest a genesisof KKT metabasites through i) slab melt migration from the downgoing oceanic crust, ii) low-degree melting ofthe garnet-bearing peridotite in the mantle wedge metasomatized by the slab melts, iii) slab melt - peridotiteinteraction triggering increasing Nb concentrations and iv) NEB generation in an arc-related environment. Thediscovery of KKT NEB sheds new information on Paleoproterozoic subduction-zone processes and crustal growthin the Singhbhum craton.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42452815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-09-15DOI: 10.1344/geologicaacta2022.20.10
K. C. Meehan, J. Boyle
{"title":"Organic-walled tentaculids of Late Devonian (Frasnian) deposits of the Appalachian and Michigan Basins, Laurussia (NY, MI, OH)","authors":"K. C. Meehan, J. Boyle","doi":"10.1344/geologicaacta2022.20.10","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.10","url":null,"abstract":"This is the first report of organic-walled tentaculid remains from Givetian through Frasnian age deposits of the Michigan and Appalachian Basins in western Laurussia. This adds to the geographic scope of similar finds that have been described from the Frasnian through the Famennian in eastern Laurussia. However, those previous specimens were retrieved through palynological preparations and more closely resemble sheath structures rather than the full forms found herein, which were retrieved through complete maceration with ammonium surfactants.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47046909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-09-08DOI: 10.1344/geologicaacta2022.20.9
H. Handoyo, I. DeFelipe, R. Martín-Banda, J. García-Mayordomo, D. Martí, J. J. Martínez-Díaz, J. Insua-Arévalo, Teresa Teixidó, J. Alcalde, I. Palomeras, R. Carbonell
{"title":"Characterization of the shallow subsurface structure across the Carrascoy Fault System (SE Iberian Peninsula) using P-wave tomography and Multichannel Analysis of Surface Waves","authors":"H. Handoyo, I. DeFelipe, R. Martín-Banda, J. García-Mayordomo, D. Martí, J. J. Martínez-Díaz, J. Insua-Arévalo, Teresa Teixidó, J. Alcalde, I. Palomeras, R. Carbonell","doi":"10.1344/geologicaacta2022.20.9","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.9","url":null,"abstract":"The seismicity in the SE Iberian Peninsula is distributed parallel to the coast in a well-developed strike-slip fracture system known as the Eastern Betic Shear Zone (EBSZ). This work focuses on the characterization of the shallow subsurface structure of the Algezares-Casas Nuevas Fault, within the Carrascoy Fault System of the EBSZ. The Carrascoy Fault borders the Guadalentín Depression to the south, which is a densely populated area with extensive agricultural activity. Therefore, this faults system represents a seismic hazard with significant social and economic implications. We have constructed two velocity-depth models based on P-wave tomography and Multichannel Analysis of Surface Waves (MASW) acquired from seismic reflection data. The resulting velocity models have allowed us to interpret the first ~250m depth and have revealed: i) the thickness of the critical zone; ii) the geometry of the Algezares-Casas Nuevas Fault; iii) the depth of the Messinian/Tortonian contact and iv) the presence of blind thrusts and damage zones under the Guadalentín Depression. Our results have also helped us to estimate an apparent vertical slip rate of 0.66±0.06m/ky for the Algezares-Casas Nuevas Fault since 209.1±6.2ka. Our results provide a methodological and backflow protocol to study the shallow subsurface of active faults, complementing previous geological models based on paleoseismological trenches, and can be used to improve the seismic hazard assessment of tectonically active regions around the world.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44417968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-07-28DOI: 10.1344/geologicaacta2022.20.7
J. Soler, S. Meng, L. Moreno, I. Neretnieks, Longcheng Liu, P. Kekäläinen, M. Hokr, J. Říha, A. Vetešník, D. Reimitz, Jakub Višňák, D. Vopálka, Klaus-Peter Kröhn, Y. Tachi, Tsuyoshi Ito, U. Svensson, A. Iraola, P. Trinchero, M. Voutilainen, G. Deissmann, D. Bosbach, D. Park, S. Ji, L. Gvoždík, Martin Milický, M. Polak, B. Gylling, B. Lanyon
{"title":"Modelling of the LTDE-SD radionuclide diffusion experiment in crystalline rock at the Äspö Hard Rock Laboratory (Sweden)","authors":"J. Soler, S. Meng, L. Moreno, I. Neretnieks, Longcheng Liu, P. Kekäläinen, M. Hokr, J. Říha, A. Vetešník, D. Reimitz, Jakub Višňák, D. Vopálka, Klaus-Peter Kröhn, Y. Tachi, Tsuyoshi Ito, U. Svensson, A. Iraola, P. Trinchero, M. Voutilainen, G. Deissmann, D. Bosbach, D. Park, S. Ji, L. Gvoždík, Martin Milický, M. Polak, B. Gylling, B. Lanyon","doi":"10.1344/geologicaacta2022.20.7","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.7","url":null,"abstract":"This study shows a comparison and analysis of results from a modelling exercise concerning a field experiment involving the transport and retention of different radionuclide tracers in crystalline rock. This exercise was performed within the Swedish Nuclear Fuel and Waste Management Company (SKB) Task Force on Modelling of Groundwater Flow and Transport of Solutes (Task Force GWFTS).Task 9B of the Task Force GWFTS was the second subtask within Task 9 and focused on the modelling of experimental results from the Long Term Sorption Diffusion Experiment in situ tracer test. The test had been performed at a depth of about 410m in the Äspö Hard Rock Laboratory. Synthetic groundwater containing a cocktail of radionuclide tracers was circulated for 198 days on the natural surface of a fracture and in a narrow slim hole drilled in unaltered rock matrix. Overcoring of the rock after the end of the test allowed for the measurement of tracer distribution profiles in the rock from the fracture surface (A cores) and also from the slim hole (D cores). The measured tracer activities in the rock samples showed long profiles (several cm) for non- or weakly-sorbing tracers (Cl-36, Na-22), but also for many of the more strongly-sorbing radionuclides. The understanding of this unexpected feature was one of the main motivations for this modelling exercise. However, re-evaluation and revision of the data during the course of Task 9B provided evidence that the anomalous long tails at low activities for strongly sorbing tracers were artefacts due to cross-contamination during rock sample preparation. A few data points remained for Cs-137, Ba-133, Ni-63 and Cd-109, but most measurements at long distances from the tracer source (>10mm) were now below the reported detection limits.Ten different modelling teams provided results for this exercise, using different concepts and codes. The tracers that were finally considered were Na-22, Cl-36, Co-57, Ni-63, Ba-133, Cs-137, Cd-109, Ra-226 and Np-237. Three main types of models were used: i) analytical solutions to the transport-retention equations, ii) continuum-porous-medium numerical models, and iii) microstructure-based models accounting for small-scale heterogeneity (i.e. mineral grains, porosities and/or microfracture distributions) and potential centimetre-scale fractures. The modelling by the different teams led to some important conclusions, concerning for instance the presence of a disturbed zone (a few mm in thickness) next to the fracture surface and to the wall of the slim hole and the role of micro-fractures and cm-scale fractures in the transport of weakly sorbing tracers. These conclusions could be reached after the re-evaluation and revision of the experimental data (tracer profiles in the rock) and the analysis of the different sets of model results provided by the different teams.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45493665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-07-12DOI: 10.1344/geologicaacta2022.20.6
A. Barnolas, A. Rodríguez-Pintó, G. Bernaola, Emilio L. Pueyo, J. Tosquella, P. Arbués, R. Scholger
{"title":"The early middle Eocene transition at the Esera valley","authors":"A. Barnolas, A. Rodríguez-Pintó, G. Bernaola, Emilio L. Pueyo, J. Tosquella, P. Arbués, R. Scholger","doi":"10.1344/geologicaacta2022.20.6","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.6","url":null,"abstract":"An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nannofossil biostratigraphy is presented herein. This work was performed in shallow marine siliciclastics rich in larger foraminifera, around the Ypresian/Lutetian boundary in the Ésera valley (South-Central Pyrenees). Although the calcareous nannofossil content in the studied interval is low, not allowing a precise Y/L boundary to be recognised, the taxa found are enough to support the chronostratigraphic attribution.\u0000Data obtained in the Ésera valley section has improved the knowledge of larger benthic foraminifera (Nummulitesand Assilina) distribution through chron C21. SBZ 11 to SBZ 12 transition took place at the lowermost C21r, as shown in previous works. SBZ 12 assemblages extend into C21n, where the SBZ 12 to SBZ 13 boundary occurs. These data, obtained in shallow marine siliciclastic facies, with in situ fauna, results in a shift of the SBZ 12/SBZ 13 boundary to the Lower Lutetian, younger than previously believed. Accordingly, the Ypresian/Lutetian boundary occurs in SBZ 12.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44231446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-06-21DOI: 10.1344/geologicaacta2022.20.5
A. C. S. Ribeiro, L. O. Santos, Paulo Cerqueira Dos Santos, R. M. Almeida, R. Mendes, A. Mendes
{"title":"Distribution and provenance of heavy minerals from recent sediments of Green Lake, North Brazil, revisited","authors":"A. C. S. Ribeiro, L. O. Santos, Paulo Cerqueira Dos Santos, R. M. Almeida, R. Mendes, A. Mendes","doi":"10.1344/geologicaacta2022.20.5","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.5","url":null,"abstract":"Geostatistical and multivariate statistical analyses were applied to heavy mineral data from an Amazonian fluvial-lake system near the Tapajós River mouth to investigate the spatial distribution and source-area of sediments. Twenty-one points were investigated, and the physical characteristics of the Green Lake deepest point were determined. Sand accumulates in the lake margins and mud quantity increases towards the lake center. Heavy mineral assemblage is composed of zircon, tourmaline, kyanite, rutile, staurolite, anatase, sillimanite, garnet, and spinel. Tourmaline, staurolite, and spinel are more abundant in the southeast area of the lake, while kyanite is dominant in the north area and zircon is in the whole lake except in its southeast area. Zircon - tourmaline and zircon - staurolite pairs are negatively correlated (r= -0.947 and -0.775, respectively), while tourmaline - staurolite and sillimanite - anatase pairs have a positive correlation (r= 0.628 and 0.675, respectively) which indicate different source rock types. Geostatistical analysis grouped the heavy minerals in three grups: Group 1 (tourmaline – staurolite – spinel - kyanite) and Group 2 (garnet – rutile – sillimanite - anatase) related to metamorphic source rocks ranging from medium to high grade, and Group 3 (zircon) related to acid igneous source rocks. The heavy mineral assemblage of Green Lake is analogous to the assemblage of the Alter do Chão Formation, indicating that this formation is the source of sediments of Green Lake.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49192588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geologica ActaPub Date : 2022-04-28DOI: 10.1344/geologicaacta2022.20.4
G. Seyitoğlu, B. Aktuğ, Korhan Esat, B. Kaypak
{"title":"Neotectonics of Turkey (Türkiye) and surrounding regions: a new perspective with block modelling","authors":"G. Seyitoğlu, B. Aktuğ, Korhan Esat, B. Kaypak","doi":"10.1344/geologicaacta2022.20.4","DOIUrl":"https://doi.org/10.1344/geologicaacta2022.20.4","url":null,"abstract":"This paper aims to present a new neotectonic perspective concordant with the seismic activities in Turkey and surrounding regions. The neotectonic structures have been re-evaluated mainly by using focal mechanism solutions and high-resolution satellite (Google Earth) images. The Southeast Anatolian Wedge explains thrust/blind thrust and asymmetrical folding relationship in SE Turkey, Syria, and Northern Iraq. The neotectonic structures of the Turkish-Iranian Plateau are enlightened by the rhomboidal cell model which creates a base to determine multiple intersection points between the region-wide left- and right-lateral shear zones. The releasing stepover between the North Anatolian Fault Zone and Southeast Anatolian-Zagros Fault Zone plus their connections with the Northeast Anatolian Fault Zone and the East Anatolian Fault Zone are described in a more meaningful way with the Anatolian Diagonal concept. It also clarifies the role of left-lateral shear zone in the west-southwest movement of Anatolian plate and its relationship with the Aegean and Cyprus arcs. A neotectonic region under the influence of NW-SE contraction is determined between the North Anatolian, Eskişehir, and Kırıkkale-Erbaa fault zones in which the Elmadağ-Eldivan and Abdüsselam pinched crustal wedges and the Beypazarı Blind Thrust Zone are developed. A new route for the southern branch of the North Anatolian Fault Zone is determined between Bolu and Değirmenlik (Milos) Island in the Aegean Sea via Mudurnu, Bursa, Balıkesir, and İzmir. All main neotectonic structures mentioned in this paper are evaluated by the elastic dislocation modelling and new neotectonic provinces are suggested.","PeriodicalId":55107,"journal":{"name":"Geologica Acta","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46261754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}