Alessio Fabbrini, N. Baldassini, C. Caricchi, L. Foresi, L. Sagnotti, J. Dinarès‐Turell, A. Stefano, F. Lirer, M. Menichetti, A. Winkler, S. Distefano
The Contessa Section is a reference section for the early Miocene in the Mediterranean. Along this 36 m thick section 115 samples were collected and analysed for an integrated bio-magnetostratigraphic study through the Scaglia Cinerea and Bisciaro formations. Planktonic foraminifera were analysed semi-quantitatively, while calcareous nannofossils were examined using the standard quantitative method. A reliable biozonation for both fossil groups was then accomplished. The paleomagnetic analyses identified a sequence of magnetozones, then correlated with the ATNTS using the calcareous plankton bioevents. The investigated interval extends from foraminiferal Zone P22 (Chattian) to MMi2c (Burdigalian) and from calcareous nannofossils Zone MNP25a to MNN3a, thus from Chron C7An to C5En. Therefore, the section chronologically spans from 24.80 Ma to18.10 Ma. Three hiatuses were recognised along the section: H1 at 0.63 m from the base (comprising a minimum time interval from 24.36 Ma to 23.38 Ma), H2 at 12.33 m (between 21.80 Ma and 21.35 Ma) and H3 at 34.03 (between 19.21 Ma and 18.40 Ma). All three hiatuses were correlated with regional megahiatuses identified in the North Atlantic Ocean and in the Paratethys area. Furthermore, the First Occurrenceof the calcareous nannofossil Helicosphera ampliaperta is recognised within Chron C6An.2n at 19.77 m from the base (6 m above the volcaniclastic Raffaello Level). This event provisionally defines the Aquitanian/Burdigalian boundary according to the literature. Thus, the Contessa Section is a possible candidate for the definition of theBurdigalian Global Stratigraphic Section and Point. Finally, the age of the Raffaello Level (a regional marker horizon for the early Miocene) is discussed in this new integrated stratigraphic framework, falling in Chron C6AAn and dated between 21.09 Ma and 21.08 Ma.
{"title":"In search of the Burdigalian GSSP: new evidence from the Contessa Section (Italy)","authors":"Alessio Fabbrini, N. Baldassini, C. Caricchi, L. Foresi, L. Sagnotti, J. Dinarès‐Turell, A. Stefano, F. Lirer, M. Menichetti, A. Winkler, S. Distefano","doi":"10.3301/IJG.2019.07","DOIUrl":"https://doi.org/10.3301/IJG.2019.07","url":null,"abstract":"The Contessa Section is a reference section for the early Miocene in the Mediterranean. Along this 36 m thick section 115 samples were collected and analysed for an integrated bio-magnetostratigraphic study through the Scaglia Cinerea and Bisciaro formations. Planktonic foraminifera were analysed semi-quantitatively, while calcareous nannofossils were examined using the standard quantitative method. A reliable biozonation for both fossil groups was then accomplished. The paleomagnetic analyses identified a sequence of magnetozones, then correlated with the ATNTS using the calcareous plankton bioevents. The investigated interval extends from foraminiferal Zone P22 (Chattian) to MMi2c (Burdigalian) and from calcareous nannofossils Zone MNP25a to MNN3a, thus from Chron C7An to C5En. Therefore, the section chronologically spans from 24.80 Ma to18.10 Ma. Three hiatuses were recognised along the section: H1 at 0.63 m from the base (comprising a minimum time interval from 24.36 Ma to 23.38 Ma), H2 at 12.33 m (between 21.80 Ma and 21.35 Ma) and H3 at 34.03 (between 19.21 Ma and 18.40 Ma). All three hiatuses were correlated with regional megahiatuses identified in the North Atlantic Ocean and in the Paratethys area. Furthermore, the First Occurrenceof the calcareous nannofossil Helicosphera ampliaperta is recognised within Chron C6An.2n at 19.77 m from the base (6 m above the volcaniclastic Raffaello Level). This event provisionally defines the Aquitanian/Burdigalian boundary according to the literature. Thus, the Contessa Section is a possible candidate for the definition of theBurdigalian Global Stratigraphic Section and Point. Finally, the age of the Raffaello Level (a regional marker horizon for the early Miocene) is discussed in this new integrated stratigraphic framework, falling in Chron C6AAn and dated between 21.09 Ma and 21.08 Ma.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2019.07","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45997551","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}
F. Donda, U. Tinivella, E. Gordini, G. Panieri, V. Volpi, D. Civile, E. Forlin, L. Facchin, M. Burca, A. Cova, G. Ferrante
A multidisciplinary approach has been used for the first time to study the widespread occurrence of hydrocarbon seeps in the northern Adriatic Sea. Geological, geophysical and geochemical analyses were performed to identify and characterize the gas-charged fluids occurring throughout the Plio-Quaternary succession, and to date the shallow gas seeping at three leakage sites. The analysis of CHIRP, morpho-bathymetric and multichannel seismic data allowed us toidentify different types of gas-related features, which occur within the whole Plio-Quaternary succession up to the seafloor and to the water column. Quantitative analyses of CHIRP data were conducted to better define, characterize and quantify the gas occurrence within the uppermost stratigraphic succession. CHIRP data also allowed the identification of the gas leakage sites. Three gas seepage areas were sampled with the aim to determine the gas composition and origin.The isotopic analyses revealed that seep gases are microbial in origin, and are primarily composed of methane, mostly formed within relatively laterally persistent Late Pleistocene peat layers, which are widely distributed throughout the northern Adriatic Sea and represent the main source of organic matter feeding the seeping gases.
{"title":"The origin of gas seeps in the Northern Adriatic Sea","authors":"F. Donda, U. Tinivella, E. Gordini, G. Panieri, V. Volpi, D. Civile, E. Forlin, L. Facchin, M. Burca, A. Cova, G. Ferrante","doi":"10.3301/IJG.2018.34","DOIUrl":"https://doi.org/10.3301/IJG.2018.34","url":null,"abstract":"A multidisciplinary approach has been used for the first time to study the widespread occurrence of hydrocarbon seeps in the northern Adriatic Sea. Geological, geophysical and geochemical analyses were performed to identify and characterize the gas-charged fluids occurring throughout the Plio-Quaternary succession, and to date the shallow gas seeping at three leakage sites. The analysis of CHIRP, morpho-bathymetric and multichannel seismic data allowed us toidentify different types of gas-related features, which occur within the whole Plio-Quaternary succession up to the seafloor and to the water column. Quantitative analyses of CHIRP data were conducted to better define, characterize and quantify the gas occurrence within the uppermost stratigraphic succession. CHIRP data also allowed the identification of the gas leakage sites. Three gas seepage areas were sampled with the aim to determine the gas composition and origin.The isotopic analyses revealed that seep gases are microbial in origin, and are primarily composed of methane, mostly formed within relatively laterally persistent Late Pleistocene peat layers, which are widely distributed throughout the northern Adriatic Sea and represent the main source of organic matter feeding the seeping gases.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2018.34","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48962859","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}
A. Zanchi, S. Zanchetta, L. Berio, F. Berra, F. Felletti
Well-preserved SSE-dipping low-angle normal faults (LANF) active during the Early Permian (Cisuralian) were recognized along the northern margin of the Orobic Basin (central Southern Alps, N Italy). These faults, which escaped most of the Alpine deformations, exhumed the Variscan basement during the deposition of the upperpart of the Lower Permian succession (Pizzo del Diavolo Formation).Fault planes show evidence of frictional processes typical of the upper crust associated with hydrothermal circulation, responsible for the deposition of cm to m thick tourmalinite and Uranium mineralization.The recognized LANFs interacted with high-angle normal faults producing half grabens that stored the Lower Permian deposits, where synsedimentary fault activity in their hangingwall is testified by abrupt vertical and lateral facies changes, thickness variations and by soft-sediment deformations. Mesoscopic structures, exposed in the hangingwall of a major LANF (the Aga-Vedello Fault system) along a synthetic high-angle normal fault, include conjugate normal faults, horst-and-graben, domino-style planar and listric faults, which clearly record synsedimentary deformations testified by liquefaction and dewatering structures, typical of pre-consolidation hydroplastic conditions. This exceptional record indicates deformations at shallow crustal level which occurred during the Early Permian along high-angle normal faults soling into the LANFs, forming the northern boundary of the Orobic Basin.The outcrop continuity, the perfectly preserved relationships among high- and low-angle normal faults together with the synsedimentary record of fault activity and the occurrence of mesoscopic faults developed during the deposition of the sediments, make this case-study an excellent reference for the analysis of extensional tectonics in synsedimentary conditions.In addition, the occurrence of large LANF systems, typical of a stress regime characterized by a vertical s1, suggests that the Lower Permian Orobic Basin was dominated by pure extension at least in the study area, alternatively to existing interpretations, which favor a transtensional origin of the basin. Strike-slip tectonics can be responsible for a later partial tectonic inversion of the basin, as testified by the angular unconformity with the overlying Upper Permian succession (Verrucano Lombardo), marking a Middle Permian stratigraphic gap.
沿奥罗比克盆地北缘（阿尔卑斯山脉中南部，意大利北部）发现了早二叠世（Cisurian）活动的保存完好的SSE倾斜低角度正断层（LANF）。这些断层逃脱了大部分阿尔卑斯山变形，在下二叠纪序列上部（Pizzo del Diavolo组）的沉积过程中挖掘出了华力西基底。断层平面显示了与热液循环相关的上地壳典型摩擦过程的证据，负责沉积厘米至米厚的电气石和铀矿化。已识别的LANF与高角度正断层相互作用，产生储存下二叠纪矿床的半地堑，其上盘的同沉积断层活动通过突然的垂直和横向相变化、厚度变化和软沉积物变形得到证实。在沿合成高角度正断层的主要LANF（Aga-Vedello断层系统）上盘中暴露的细观结构包括共轭正断层、地垒和地堑、多米诺骨牌式平面和倾斜断层，这些断层清楚地记录了液化和脱水结构证实的同沉积变形，这是典型的固结前水塑性条件。这一特殊记录表明，早二叠世期间，浅层地壳水平发生了变形，沿着高角度正断层进入LANF，形成了奥罗比克盆地的北部边界，高角度和低角度正断层之间保存完好的关系，以及断层活动的同沉积记录和沉积物沉积过程中发育的细观断层的出现，使本案例研究为分析同沉积条件下的伸展构造提供了极好的参考。此外，大型LANF系统的出现，典型的以垂直s1为特征的应力状态，表明至少在研究区域内，下二叠纪造山带盆地以纯伸展为主，而现有的解释有利于盆地的张性起源。走滑构造可能是盆地后期部分构造反转的原因，与上覆的上二叠纪层序（Verrucano Lombardo）的角度不整合证明了这一点，标志着二叠纪中期的地层间隙。
{"title":"Low-angle normal faults record Early Permian extensional tectonics in the Orobic Basin (Southern Alps, N Italy)","authors":"A. Zanchi, S. Zanchetta, L. Berio, F. Berra, F. Felletti","doi":"10.3301/IJG.2018.35","DOIUrl":"https://doi.org/10.3301/IJG.2018.35","url":null,"abstract":"Well-preserved SSE-dipping low-angle normal faults (LANF) active during the Early Permian (Cisuralian) were recognized along the northern margin of the Orobic Basin (central Southern Alps, N Italy). These faults, which escaped most of the Alpine deformations, exhumed the Variscan basement during the deposition of the upperpart of the Lower Permian succession (Pizzo del Diavolo Formation).Fault planes show evidence of frictional processes typical of the upper crust associated with hydrothermal circulation, responsible for the deposition of cm to m thick tourmalinite and Uranium mineralization.The recognized LANFs interacted with high-angle normal faults producing half grabens that stored the Lower Permian deposits, where synsedimentary fault activity in their hangingwall is testified by abrupt vertical and lateral facies changes, thickness variations and by soft-sediment deformations. Mesoscopic structures, exposed in the hangingwall of a major LANF (the Aga-Vedello Fault system) along a synthetic high-angle normal fault, include conjugate normal faults, horst-and-graben, domino-style planar and listric faults, which clearly record synsedimentary deformations testified by liquefaction and dewatering structures, typical of pre-consolidation hydroplastic conditions. This exceptional record indicates deformations at shallow crustal level which occurred during the Early Permian along high-angle normal faults soling into the LANFs, forming the northern boundary of the Orobic Basin.The outcrop continuity, the perfectly preserved relationships among high- and low-angle normal faults together with the synsedimentary record of fault activity and the occurrence of mesoscopic faults developed during the deposition of the sediments, make this case-study an excellent reference for the analysis of extensional tectonics in synsedimentary conditions.In addition, the occurrence of large LANF systems, typical of a stress regime characterized by a vertical s1, suggests that the Lower Permian Orobic Basin was dominated by pure extension at least in the study area, alternatively to existing interpretations, which favor a transtensional origin of the basin. Strike-slip tectonics can be responsible for a later partial tectonic inversion of the basin, as testified by the angular unconformity with the overlying Upper Permian succession (Verrucano Lombardo), marking a Middle Permian stratigraphic gap.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45093045","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}
Gerard Saborit, A. Mondanaro, M. Melchionna, C. Serio, F. Carotenuto, S. Tavani, M. Modafferi, Adolfo Panarello, P. Mietto, P. Raia, A. Casinos
Understanding the evolution of bipedal locomotion in humans is of paramount importance to paleoanthropologists. Such endeavor requires well-preserved dynamic evidence of fossil human locomotion we are short of. Physical models of modern human locomotion predict individuals would perform voluntary step length adjustment as a function of slope gradient in order to minimize the energetic costof locomotion while maintaining balance and reasonably comfortable gait. The famous Roccamonfina volcano “Devil’s trails”, which are Middle Pleistocene Homo fossilized trackways, provide unique opportunity to validate such predictions for fossil human individuals. We studied the best-preserved Roccamonfina Devil’s trail to ascertain the dynamic behavior of the individual who left the trackway. We found Roccamonfina’s individual moved in a way which is dynamically equivalent to modern humans, adjusting gait as to minimize energy expenditure. We derived body mass and stature estimates for such individual, which fit perfectly with previously published figures for Middle Pleistocene hominins outside Africa.
{"title":"A dynamic analysis of Middle Pleistocene human walking gait adjustment and control","authors":"Gerard Saborit, A. Mondanaro, M. Melchionna, C. Serio, F. Carotenuto, S. Tavani, M. Modafferi, Adolfo Panarello, P. Mietto, P. Raia, A. Casinos","doi":"10.3301/IJG.2019.03","DOIUrl":"https://doi.org/10.3301/IJG.2019.03","url":null,"abstract":"Understanding the evolution of bipedal locomotion in humans is of paramount importance to paleoanthropologists. Such endeavor requires well-preserved dynamic evidence of fossil human locomotion we are short of. Physical models of modern human locomotion predict individuals would perform voluntary step length adjustment as a function of slope gradient in order to minimize the energetic costof locomotion while maintaining balance and reasonably comfortable gait. The famous Roccamonfina volcano “Devil’s trails”, which are Middle Pleistocene Homo fossilized trackways, provide unique opportunity to validate such predictions for fossil human individuals. We studied the best-preserved Roccamonfina Devil’s trail to ascertain the dynamic behavior of the individual who left the trackway. We found Roccamonfina’s individual moved in a way which is dynamically equivalent to modern humans, adjusting gait as to minimize energy expenditure. We derived body mass and stature estimates for such individual, which fit perfectly with previously published figures for Middle Pleistocene hominins outside Africa.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2019.03","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47645793","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}
C. Corradini, M. Corriga, M. Pondrelli, P. Serventi, L. Simonetto, A. Ferretti
The Rio Malinfier West section in the central Carnic Alps provides important data on the evolution of the Lochkovian (Lower Devonian) sedimentary basins of the Variscan belt. An exposure of about 100 m documents five lithostratigraphic units (Alticola, Rauchkofel, Nolbling, La Valute and Findenig formations) spanning in age from the latest Silurian to the Early Devonian. The complex structural setting of the section results from a main fault dividing the succession in two separate segments. A precise lithological characterization was carried on at a macro- and micro-scale. Macrofauna includes, among others, abundant cephalopods and crinoids (loboliths). The biostratigraphic assignment to the uppermost Silurian-lowermost Devonian (Lochkovian) was possible basing on a moderately abundant conodont fauna, that provided thirty-two taxa belonging to thirteen genera, among which the new species Zieglerodina schoenlaubi. The Rio Malinfier West section testifies that a differentiation between shallow and deep water parts of the Devonian basin was already present during Lochkovian times, prior to the establishment of the conditions enabling the colonization of the well-known upper Lower-Middle Devonian reef buildings.
{"title":"Lochkovian (Lower Devonian) marine-deposits from the Rio Malinfier West section (Carnic Alps, Italy)","authors":"C. Corradini, M. Corriga, M. Pondrelli, P. Serventi, L. Simonetto, A. Ferretti","doi":"10.3301/IJG.2018.33","DOIUrl":"https://doi.org/10.3301/IJG.2018.33","url":null,"abstract":"The Rio Malinfier West section in the central Carnic Alps provides important data on the evolution of the Lochkovian (Lower Devonian) sedimentary basins of the Variscan belt. An exposure of about 100 m documents five lithostratigraphic units (Alticola, Rauchkofel, Nolbling, La Valute and Findenig formations) spanning in age from the latest Silurian to the Early Devonian. The complex structural setting of the section results from a main fault dividing the succession in two separate segments. A precise lithological characterization was carried on at a macro- and micro-scale. Macrofauna includes, among others, abundant cephalopods and crinoids (loboliths). The biostratigraphic assignment to the uppermost Silurian-lowermost Devonian (Lochkovian) was possible basing on a moderately abundant conodont fauna, that provided thirty-two taxa belonging to thirteen genera, among which the new species Zieglerodina schoenlaubi. The Rio Malinfier West section testifies that a differentiation between shallow and deep water parts of the Devonian basin was already present during Lochkovian times, prior to the establishment of the conditions enabling the colonization of the well-known upper Lower-Middle Devonian reef buildings.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2018.33","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47397448","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}
This paper describes the possible karst landforms observed in the Light Toned Deposits (LTDs) located within the Cagli crater, a medium size crater located in northern Sinus Meridiani, an area near the equatorial region of Mars.A morphological and morphometric survey of the LTDs surface morphologies through an integrated analysis of the available Reconnaissance Mars Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images highlighted the presence of shallow depressions that display different shapes and sizes.The Martian landforms were interpreted as sinkhole resembling similarly karst landforms that can be observed both in different karst terrains on the Earth and in other regions of Mars.The karst landforms observed highlight the evaporitic origin ofthese materials and suggest both climatic change and the presence ofliquid water, probably due to ice melting, during the late Amazonianperiod.
{"title":"Very recent karst landforms within Cagli crater, Sinus Meridiani, Mars","authors":"D. Baioni","doi":"10.3301/IJG.2019.05","DOIUrl":"https://doi.org/10.3301/IJG.2019.05","url":null,"abstract":"This paper describes the possible karst landforms observed in the Light Toned Deposits (LTDs) located within the Cagli crater, a medium size crater located in northern Sinus Meridiani, an area near the equatorial region of Mars.A morphological and morphometric survey of the LTDs surface morphologies through an integrated analysis of the available Reconnaissance Mars Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images highlighted the presence of shallow depressions that display different shapes and sizes.The Martian landforms were interpreted as sinkhole resembling similarly karst landforms that can be observed both in different karst terrains on the Earth and in other regions of Mars.The karst landforms observed highlight the evaporitic origin ofthese materials and suggest both climatic change and the presence ofliquid water, probably due to ice melting, during the late Amazonianperiod.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45118635","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}
Two samples of quartz-rich sandstones belonging to Bifurto Formation in Southern Apennines, were studied for their petrographical, geochemical and geochronological (U-Pb detrital zircon ages) features and compared with those of sandstones from five stratigraphic sections of the Numidian Flysch in SouthernItaly. The purpose of this comparison is to assess the homogeneity and provenance of detritus because quartz-rich sandstones of both formations are coeval having Burdigalian p.p. - Early Langhian age.The depositional domain of the Bifurto formation was located on the sinking Campania-Lucania carbonate platform whereas that of Numidian Flysch was within the Lagonegro-Molise Basin east of the Campania-Lucania Platform. The Bifurto sandstones have sub-arkose - quartzarenitic composition with high Fe2O3 contents (Fe2O3 in the range 2.85 wt% - 4.83 wt%), however, the whole composition varies in the same compositional range of the Numidian Flysch sandstones.The U-Pb detrital zircon ages in Bifurto sandstones range from 2551±40 Ma to 425±9 Ma and 93% of these age data is comprised in the same time lapse of detrital zircon ages of Numidian Flysch sandstones (3047±13 to 516±19 Ma). These ages suggest a provenance area consisting of ancient orogens in which Precambrian and Silurian rocks are present. The absence of Paleozoic - Mesozoic ages excludes provenance from Variscan or Alpine rocks. On this basis, the African Craton represents the exclusive source area of Bifurto sandstones as well as of Numidian Flysch sandstones outcropping in Southern Apennines. Similar deductions have been proposed for Numidian sandstones outcropping along the Betic and Maghrebian chains from Spain to Morocco, Algeria and Sicily.
{"title":"U-Pb detrital zircon ages and compositional features of Bifurto quartz-rich sandstones from Southern Apennines (Southern Italy): comparison with Numidian Flysch sandstones to infer source area","authors":"A. Fornelli, S. Gallicchio, F. Micheletti","doi":"10.3301/IJG.2019.02","DOIUrl":"https://doi.org/10.3301/IJG.2019.02","url":null,"abstract":"Two samples of quartz-rich sandstones belonging to Bifurto Formation in Southern Apennines, were studied for their petrographical, geochemical and geochronological (U-Pb detrital zircon ages) features and compared with those of sandstones from five stratigraphic sections of the Numidian Flysch in SouthernItaly. The purpose of this comparison is to assess the homogeneity and provenance of detritus because quartz-rich sandstones of both formations are coeval having Burdigalian p.p. - Early Langhian age.The depositional domain of the Bifurto formation was located on the sinking Campania-Lucania carbonate platform whereas that of Numidian Flysch was within the Lagonegro-Molise Basin east of the Campania-Lucania Platform. The Bifurto sandstones have sub-arkose - quartzarenitic composition with high Fe2O3 contents (Fe2O3 in the range 2.85 wt% - 4.83 wt%), however, the whole composition varies in the same compositional range of the Numidian Flysch sandstones.The U-Pb detrital zircon ages in Bifurto sandstones range from 2551±40 Ma to 425±9 Ma and 93% of these age data is comprised in the same time lapse of detrital zircon ages of Numidian Flysch sandstones (3047±13 to 516±19 Ma). These ages suggest a provenance area consisting of ancient orogens in which Precambrian and Silurian rocks are present. The absence of Paleozoic - Mesozoic ages excludes provenance from Variscan or Alpine rocks. On this basis, the African Craton represents the exclusive source area of Bifurto sandstones as well as of Numidian Flysch sandstones outcropping in Southern Apennines. Similar deductions have been proposed for Numidian sandstones outcropping along the Betic and Maghrebian chains from Spain to Morocco, Algeria and Sicily.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2019.02","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48594813","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}
F. Accaino, M. Busetti, G. Böhm, L. Baradello, A. Affatato, M. Cin, D. Nieto
We present the results of a geophysical study carried out in the Isonzo Plain (NE of Italy), where the Paleogene External Dinarides and the Neogene eastern Southern Alps merge. We aim to provide imaging on the geological and tectonic setting in the area of convergence of the two chains. To this purpose multichannel seismic and geo-electrical profiles were acquired. Seismic processing and tomographic inversion of the first arrivals of multichannel seismic data were performed, allowing us to define geometries and velocities of the buried structures.Our data indicate the occurrence of a deformed Dinaric foredeep due to the Paleogene south-west migration of the External Dinaric chain and to the Neogene tectonic activity of the S-verging eastern South-Alpine chain. In addition, Plio-Quaternary transpressional fault systems produced structural highs such as the rocky outcrop of the Farra Hills rising from the plain. Plio-Quaternary tectonic activity displaced the late Miocene - Pliocene erosive surface at the top of the terrigenous sediment that fills the foredeep. The imaging of the buried structures provide a possible correlation with those outcropping in the Collio Hills and Karst Plateau.
{"title":"Geophysical investigation of the Isonzo Plain (NE Italy): imaging of the Dinaric-Alpine chain convergence zone","authors":"F. Accaino, M. Busetti, G. Böhm, L. Baradello, A. Affatato, M. Cin, D. Nieto","doi":"10.3301/IJG.2019.01","DOIUrl":"https://doi.org/10.3301/IJG.2019.01","url":null,"abstract":"We present the results of a geophysical study carried out in the Isonzo Plain (NE of Italy), where the Paleogene External Dinarides and the Neogene eastern Southern Alps merge. We aim to provide imaging on the geological and tectonic setting in the area of convergence of the two chains. To this purpose multichannel seismic and geo-electrical profiles were acquired. Seismic processing and tomographic inversion of the first arrivals of multichannel seismic data were performed, allowing us to define geometries and velocities of the buried structures.Our data indicate the occurrence of a deformed Dinaric foredeep due to the Paleogene south-west migration of the External Dinaric chain and to the Neogene tectonic activity of the S-verging eastern South-Alpine chain. In addition, Plio-Quaternary transpressional fault systems produced structural highs such as the rocky outcrop of the Farra Hills rising from the plain. Plio-Quaternary tectonic activity displaced the late Miocene - Pliocene erosive surface at the top of the terrigenous sediment that fills the foredeep. The imaging of the buried structures provide a possible correlation with those outcropping in the Collio Hills and Karst Plateau.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2019.01","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46110319","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}
The Oligocene Porto Badisco Calcarenite (Apulian Carbonate Platform, southern Italy) contains very rich and diverse assemblages of larger benthic foraminifera. In this paper we provide the first comprehensive taxonomic study of Nummulitids and Lepidocyclinids, based on a biometric approach to species identification. The largerforaminiferal assemblage is dominated by Eulepidina, Heterostegina and Spiroclypeus. Nummulites, Operculina and Nephrolepidina make a subordinate but significant contribution. The concurrent range of the larger foraminiferal species present in the Porto Badisco Calcarenite, and in particular the presence of Spiroclypeus margaritatus and of Miogypsinoides complanatus-formosensis, indicates the late Oligocene Shallow Benthic Zone (SBZ) 23. The taxonomic composition of the larger foraminiferal assemblage of the Apulian Carbonate Platform is very similar to coeval assemblages of other localities of the western Tethyan realm (southern France, southern Spain, Malta, Greece), while some typical components of the SBZ 23 assemblages, like Heterostegina assilinoides and Eulepidina dilatata, are missing in more eastern areas (Turkey, India). Strontium isotope stratigraphy gives an age of 23.6 ± 0.5 Ma for the lower part of the Porto Badisco Calcarenite, constraining the chronostratigraphic calibration of the SBZ 23 within the latest Chattian. This calibration further supports the correlation between the SBZ 23 of the European Basins biozonal scheme with the Te 4 stage of the East Indian Letter Classification.
{"title":"Nummulitids, Lepidocyclinids and strontium isotope stratigraphy of the Porto Badisco Calcarenite (Salento Peninsula, southern Italy). Implications for the biostratigraphy and paleobiogeography of Oligocene larger benthic foraminifera","authors":"M. Parente, G. Less","doi":"10.3301/IJG.2019.04","DOIUrl":"https://doi.org/10.3301/IJG.2019.04","url":null,"abstract":"The Oligocene Porto Badisco Calcarenite (Apulian Carbonate Platform, southern Italy) contains very rich and diverse assemblages of larger benthic foraminifera. In this paper we provide the first comprehensive taxonomic study of Nummulitids and Lepidocyclinids, based on a biometric approach to species identification. The largerforaminiferal assemblage is dominated by Eulepidina, Heterostegina and Spiroclypeus. Nummulites, Operculina and Nephrolepidina make a subordinate but significant contribution. The concurrent range of the larger foraminiferal species present in the Porto Badisco Calcarenite, and in particular the presence of Spiroclypeus margaritatus and of Miogypsinoides complanatus-formosensis, indicates the late Oligocene Shallow Benthic Zone (SBZ) 23. The taxonomic composition of the larger foraminiferal assemblage of the Apulian Carbonate Platform is very similar to coeval assemblages of other localities of the western Tethyan realm (southern France, southern Spain, Malta, Greece), while some typical components of the SBZ 23 assemblages, like Heterostegina assilinoides and Eulepidina dilatata, are missing in more eastern areas (Turkey, India). Strontium isotope stratigraphy gives an age of 23.6 ± 0.5 Ma for the lower part of the Porto Badisco Calcarenite, constraining the chronostratigraphic calibration of the SBZ 23 within the latest Chattian. This calibration further supports the correlation between the SBZ 23 of the European Basins biozonal scheme with the Te 4 stage of the East Indian Letter Classification.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3301/IJG.2019.04","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49592071","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}
The investigation of the benthic foraminifers from three stratigraphic sections of the Caltavuturo Formation, exposed in the Madonie Mountains, gave evidences of vertical distribution of deep-water foraminiferal assemblages. The sedimentary succession exposed at the study sites consists of red to grey clay with interbeddedbiodetrital limestone mainly composed by larger foraminiferal tests and resulting from turbidity or debris flows. Since planktonic foraminifers and nannofossils are absent or poorly preserved, the sedimentary successions have been referred to the late Eocene to the early Oligocene by the occurrence of displaced tests of largerforaminifers which are considered coeval to the foraminifers in the clay.Biostratigraphic correlations have been attempted by means of the first occurrence of lepidocyclinids and biometrical mean values of populations of Nephrolepidina praemarginata. Deep water agglutinated foraminifers (DWAF) assemblages in the background clay allowed the reconstruction of environmental variations marking a deepening tendency.Two breccia beds, one of which reaches 2.5 m in thickness, mainly composed of packstone-grainstone with Early and Late Cretaceous larger foraminifers and fragments of rudists, occur in the northern stratigraphic section as a result of the erosion of the paleoslope surface composed of the Upper Cretaceous rudist member of the Crisanti Formation. The lack of these deposits in the other twosections is due to bypassing. The assemblages and the stratigraphic settings are consistent with a deposition along a continental slope deepening northward, suggesting an ‘African’ provenance of the flows which contributed to displace and rework shallow-water material.
{"title":"Benthic foraminiferal assemblages from the late Eocene to the early Oligocene of the Caltavuturo Formation in the Madonie Mountains (Sicily): a tool for correlation","authors":"A. Benedetti","doi":"10.3301/IJG.2018.25","DOIUrl":"https://doi.org/10.3301/IJG.2018.25","url":null,"abstract":"The investigation of the benthic foraminifers from three stratigraphic sections of the Caltavuturo Formation, exposed in the Madonie Mountains, gave evidences of vertical distribution of deep-water foraminiferal assemblages. The sedimentary succession exposed at the study sites consists of red to grey clay with interbeddedbiodetrital limestone mainly composed by larger foraminiferal tests and resulting from turbidity or debris flows. Since planktonic foraminifers and nannofossils are absent or poorly preserved, the sedimentary successions have been referred to the late Eocene to the early Oligocene by the occurrence of displaced tests of largerforaminifers which are considered coeval to the foraminifers in the clay.Biostratigraphic correlations have been attempted by means of the first occurrence of lepidocyclinids and biometrical mean values of populations of Nephrolepidina praemarginata. Deep water agglutinated foraminifers (DWAF) assemblages in the background clay allowed the reconstruction of environmental variations marking a deepening tendency.Two breccia beds, one of which reaches 2.5 m in thickness, mainly composed of packstone-grainstone with Early and Late Cretaceous larger foraminifers and fragments of rudists, occur in the northern stratigraphic section as a result of the erosion of the paleoslope surface composed of the Upper Cretaceous rudist member of the Crisanti Formation. The lack of these deposits in the other twosections is due to bypassing. The assemblages and the stratigraphic settings are consistent with a deposition along a continental slope deepening northward, suggesting an ‘African’ provenance of the flows which contributed to displace and rework shallow-water material.","PeriodicalId":49317,"journal":{"name":"Italian Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42270645","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}
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