70 research outputs found

    The Karst Dinarides are Composed of Relics of a Single Mesozoic Platform: Facts and Consequences

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    Croatian geological literature during the mid nineteen-eighties and nineties was marked by the appearance of a new geotectonic concept of the Dinarides proposing that the recent, very complex structural setting is a direct consequence of a specific palaeogeographic relationship during the Mesozoic, i.e. the proposed existence of two carbonate platforms separated by a long-lasting deep marine area (interplatform trough). Although the idea was very interesting and provoked discussion, resulting in the questioning of formerly established concepts, detailed analysis of available data indicate that the Karst Dinarides (External Dinarides) were formed by the destruction of a single, although morphologically considerably variable shallow water carbonate platform. This platform was in some periods very dynamic because of its palaeogeographic position during the Mesozoic, resulting in many periods of large-scale facies differentiation, especially during the Late Cretaceous. The final disintegration of the platform area culminated in the formation of flysch trough(s) in the latest Cretaceous and Palaeogene and the subsequent uplift of the Dinarides. Recently there have been some misunderstandings resulting from the imprecise use of newly established terms, which are, by circular logic, used to connect recent geotectonic relationships with Mesozoic palaeogeography without adequate material proof. Therefore, the terms Dinaricum and Adriaticum should be redefined and used only for description of the recent tectonic pattern, without implying a palaeogeographic component, since during the Mesozoic they represented a single entity. Additional confusion is added by different names used for the same shallow water carbonate platform. Probably the best, although not the ideal name is the most frequently used one: the Adriatic Carbonate Platform. Its duration may be estimated from the Late Lias to the Late Cretaceous, representing the most important part of a thick carbonate succession in the Karst Dinarides (ranging from Carboniferous to Eocene)

    The Karst Dinarides are Composed of Relics of a Single Mesozoic Platform: Facts and Consequences

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    Croatian geological literature during the mid nineteen-eighties and nineties was marked by the appearance of a new geotectonic concept of the Dinarides proposing that the recent, very complex structural setting is a direct consequence of a specific palaeogeographic relationship during the Mesozoic, i.e. the proposed existence of two carbonate platforms separated by a long-lasting deep marine area (interplatform trough). Although the idea was very interesting and provoked discussion, resulting in the questioning of formerly established concepts, detailed analysis of available data indicate that the Karst Dinarides (External Dinarides) were formed by the destruction of a single, although morphologically considerably variable shallow water carbonate platform. This platform was in some periods very dynamic because of its palaeogeographic position during the Mesozoic, resulting in many periods of large-scale facies differentiation, especially during the Late Cretaceous. The final disintegration of the platform area culminated in the formation of flysch trough(s) in the latest Cretaceous and Palaeogene and the subsequent uplift of the Dinarides. Recently there have been some misunderstandings resulting from the imprecise use of newly established terms, which are, by circular logic, used to connect recent geotectonic relationships with Mesozoic palaeogeography without adequate material proof. Therefore, the terms Dinaricum and Adriaticum should be redefined and used only for description of the recent tectonic pattern, without implying a palaeogeographic component, since during the Mesozoic they represented a single entity. Additional confusion is added by different names used for the same shallow water carbonate platform. Probably the best, although not the ideal name is the most frequently used one: the Adriatic Carbonate Platform. Its duration may be estimated from the Late Lias to the Late Cretaceous, representing the most important part of a thick carbonate succession in the Karst Dinarides (ranging from Carboniferous to Eocene)

    Stanja spinskih dubleta u spektru 9Be u modelu grozdova

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    The structure of the 9Be low-lying spectrum is studied within the cluster model α + α + n. In the model, the total orbital momentum is fixed for each energy level. Thus each level is determined as a member of the spin-flip doublet corresponding to the total orbital momentum (L π = 0+, 2 +, 4 +, 1 −, 2 −, 3 −, 4 −) of the system. The Ali-Bodmer potential (model E) is applied for the αα interaction. We employ a local αn potential which was constructed to reproduce the α − n scattering data. The Pauli blocking is simulated by the repulsive core of the s-wave components of these potentials. Configuration-space Faddeev equations are used to calculate the energy of the bound state (Ecalc = −1.493 MeV vs. Eexp = −1.5735 MeV) and resonances. A variant of the method of analytical continuation in the coupling constant is applied to calculate energies of the low-lying levels. Available 9Be spectral data are satisfactorily reproduced by the proposed model.Proučavaju se niskoležeća stanja 9Be polazeći od modela grozda α+α+n. Za svako stanje se uzima određen ukupni moment impulsa. Tako je svako stanje određeno kao član spinskih dubletnih stanja s danim ukupnim momentom impulsa sustava (L π = 0+, 2 +, 4 +, 1 −, 2 −, 3 −, 4 −). Primjenjuje se Ali-Bodmerov potencijal (model E) za međudjelovanje αα. Za međudjelovanje αn primjenjuje se lokalni αn potencijal, koji se podešava kako bi se postigao sklad s podacima za α − n raspršenje. Paulijeva zabrana se postiže s odbojnom jezgrom za s valove tih potencijala. Za računanje energije vezanog stanja (Ecalc = −1.493 MeV vs. Eexp = −1.5735 MeV) i rezonancija rabe se Faddeevljeve jednadžbe u običnom prostoru. Za računanje energija niskoležećih stanja primjenjuje se inačica metode za analitičko nastavljanje konstante međudjelovanja. Ovim modelom postižemo dobar sklad s poznatim spektralnim podacima za 9Be

    Stanja spinskih dubleta u spektru 9Be u modelu grozdova

    Get PDF
    The structure of the 9Be low-lying spectrum is studied within the cluster model α + α + n. In the model, the total orbital momentum is fixed for each energy level. Thus each level is determined as a member of the spin-flip doublet corresponding to the total orbital momentum (L π = 0+, 2 +, 4 +, 1 −, 2 −, 3 −, 4 −) of the system. The Ali-Bodmer potential (model E) is applied for the αα interaction. We employ a local αn potential which was constructed to reproduce the α − n scattering data. The Pauli blocking is simulated by the repulsive core of the s-wave components of these potentials. Configuration-space Faddeev equations are used to calculate the energy of the bound state (Ecalc = −1.493 MeV vs. Eexp = −1.5735 MeV) and resonances. A variant of the method of analytical continuation in the coupling constant is applied to calculate energies of the low-lying levels. Available 9Be spectral data are satisfactorily reproduced by the proposed model.Proučavaju se niskoležeća stanja 9Be polazeći od modela grozda α+α+n. Za svako stanje se uzima određen ukupni moment impulsa. Tako je svako stanje određeno kao član spinskih dubletnih stanja s danim ukupnim momentom impulsa sustava (L π = 0+, 2 +, 4 +, 1 −, 2 −, 3 −, 4 −). Primjenjuje se Ali-Bodmerov potencijal (model E) za međudjelovanje αα. Za međudjelovanje αn primjenjuje se lokalni αn potencijal, koji se podešava kako bi se postigao sklad s podacima za α − n raspršenje. Paulijeva zabrana se postiže s odbojnom jezgrom za s valove tih potencijala. Za računanje energije vezanog stanja (Ecalc = −1.493 MeV vs. Eexp = −1.5735 MeV) i rezonancija rabe se Faddeevljeve jednadžbe u običnom prostoru. Za računanje energija niskoležećih stanja primjenjuje se inačica metode za analitičko nastavljanje konstante međudjelovanja. Ovim modelom postižemo dobar sklad s poznatim spektralnim podacima za 9Be

    Foraminiferal Assemblages in the Cenomanian of the Buzet-Savudrija Area (Northwestern Istria, Croatia)

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    In the Cenomanian shallow-water carbonates of Northwestern Istria five biostratigraphic zones have been established: CEN-1 Ovalveolina maccagnoae and Sellialveolina viallii biozone in the early Lower Cenomanian; CEN-2 O. maccagnoae to Chrysalidina gradata interval zone in the late Lower Cenomanian; CEN-3 C. gradata biozone in the early Middle Cenomanian, locally subdivided into two subzones: CEN-3a C. gradata and orbitolinids (lower part) CEN-3b C. gradata without orbitolinids (upper part); CEN-4 C. gradata and Broeckina (P.) balcanica biozone in the late Middle Cenomanian, and CEN-5 C. gradata, B. (P.) balcanica and Vidalina radoicicae biozone in the Upper Cenomanian
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