The paleomagnetism of the Upper Cretaceous magmatic rocks in the Banat area of South Carpathians: tectonic implications

doi:10.1016/0040-1951(92)90462-F

Tectonophysics

Volume 213, Issues 3–4, 15 November 1992, Pages 341-352

https://doi.org/10.1016/0040-1951(92)90462-F Get rights and content

Abstract

Forty-four sites were sampled in Upper Cretaceous magmatic rocks in the western part of the Southern Carpathians (Banat area) for a paleomagnetic study. After detailed AF demagnetization, only 10 sites yielded primary remanent magnetizations, the directions of which are similar to those identified in Senonian magmatic rocks from the Apuseni Mountains and the Haţeg and Rusca Montană Basins. The mean paleomagnetic pole for these three areas is compared with those from coeval formations of stable Europe and stable Africa. This comparison shows a large clockwise rotation, both with respect to Africa and Europe, and a northward transport to reach their present-day position during the Tertiary. The relations with adjacent zones of the Tethys mobile belt are also discussed.

References (41)

M. Boccaletti et al.
Hypothesis on the plate tectonic evolution of the Carpatho-Balkan arcs
Earth Planet. Sci. Lett.
(1974)
B.C. Burchfiel
Eastern European Alpine system and the Carpathian orocline as an example of collision tectonics
E. Márton
Paleomagnetism and tectonics in the Mediterranean region
J. Geodyn.
(1987)
E. Márton et al.
A refined apparent polar wander curve for the Transdanubian Central Mountains and its bearing on the Mediterranean tectonic history
Tectonophysics
(1983)
E. Márton et al.
Structural applications and discussion of a paleomagnetic post-Paleozoic data base for the Central Mediterranean
Phys. Earth Planet. Inter.
(1990)
J.G. Mitchell et al.
Radiogenic argon and major-element loss from biotite during natural weathering: a geochemical approach to the interpretation of potassium-argon ages of detrital biotite
Chem. Geol. (Isotope Geoscience Section)
(1988)
Şt. Pătraşcu et al.
Tectonic implications of paleomagnetic research into Upper Cretaceous magmatic rocks in the Apuseni Mountains, Romania
Tectonophysics
(1990)
P.N. Popov
Tectonics of the Banat-Srednogorie rift
Tectonophysics
(1987)
M. Westphal et al.
Paleomagnetic implications on the evolution of the Tethys belt from the Atlantic Ocean to the Pamirs since the Triassic
J. Andrei et al.
Spatial distribution and structural images of Banatites from Romania deduced from gravity and magnetic data
Rev. Roum. Géol., Géophys. Géogr.-Géophys.
(1989)

J.A. As

Instruments and measuring methods in paleomagnetic research

Meded. Verb. K.N.M.I.

(1960)

J.A. As

The measurement of the anisotropy of the susceptibility with an astatic magnetometer

Z. Balla

The Carpathian loop and the Pannonian Basin: a kinematic analysis

Geophys. Trans.

(1985)

M.E. Beck

Paleomagnetic record of plate-margin tectonic processes along the western edge of North America

J. Geophys. Res.

(1980)

I. Berbeleac

Zăcăminte minerale şi tectonica globală

G. Cioflică

Cooper mineralizations related to Upper Cretaceous-Paleogene magmatites in Romania

Rev. Géol., Géophys. Géogr.-Géol.

(1989)

P. Dagley et al.

Magnetic polarity stratigraphy of the Tertiary igneous rocks of Skye, Scotland

Geophys. J. Int.

(1990)

H.H. Demarest

Error analysis for the determination of tectonic rotation from paleomagnetic data

J. Geophys. Res.

(1983)

R.R. Doell et al.

Determination of the magnetic polarity of rock samples in the field

U.S. Geol. Surv., Prof. Pap., 450-D

(1962)

R.A. Fisher

Dispersion on a sphere

Cited by (44)

Strain partitioning in a large intracontinental strike-slip system accommodating backarc-convex orocline formation: The Circum-Moesian Fault System of the Carpatho-Balkanides
2022, Global and Planetary Change
Citation Excerpt :
The N-, NE- and E-ward Miocene roll-back and closure of the Carpathian embayment have created ultimately the two oroclines observed in the double Carpatho-Balkanides loop (Fig. 1a; Ustaszewski et al., 2008). While the South Carpathians segment underwent a coeval gradual clockwise rotation of up to 90° (e.g., Balla, 1984, 1986, 1987; de Leeuw et al., 2013; Dupont-Nivet et al., 2005; Pătraşcu et al., 1990, 1992, 1993; Panaiotu and Panaiotu, 2010), this rotation decreases to 25°-30° in the Serbian Carpathians segment and becomes negligible in the Balkanides (Lesić et al., 2019; van Hinsbergen et al., 2008). The Paleocene – Eocene orogen-parallel extension reactivated the inherited basal thrust of the Getic unit in the South Carpathians and exhumed the Danubian nappe-stack along an extensional detachment, forming the Danubian window (Figs. 1b, 2; Fügenschuh and Schmid, 2005; Matenco and Schmid, 1999; Moser et al., 2005; Schmid et al., 1998).
The evolution of oroclines is often driven by the interplay of subduction and indentation associated with complex patterns of deformation transfer from shortening to strike-slip and extension. We study the kinematics and mechanics of indentation in an orocline with a backarc-convex geometry, the European Carpatho-Balkanides Mountains. Within this orocline, the kinematic evolution of the Serbian Carpathians segment is less understood. The results demonstrate that the overall deformation was accommodated by the Circum-Moesian Fault System surrounding the Moesian indenter, where strain was partitioned in a complex network of coeval strike-slip, thrust and normal faults. This system represents one of the largest European intracontinental strike-slip deformation zones, with a northward-increasing accumulated 140 km dextral offset along previously known and newly found faults. These strike-slip faults transfer a significant part of their offset eastwards to thrusting in the Balkanides and westwards to orogen-parallel extension and the formation of intramontane basins. The correlation with paleogeographic and geodynamic reconstructions demonstrates that the overall formation of the fault system is driven by subduction of the Carpathian embayment, resulting in laterally variable amounts of translation and rotation associated with indentation of the Moesian Platform. The onset of Carpathian slab retreat and backarc extension at 20 Ma has dramatically increased the rates of dextral deformation from ~3.5 mm/yr to ~2 cm/yr, facilitated by the pull exerted by the retreating slab. Our study demonstrates that indentation requires a strain partitioning analysis that is adapted to the specificity of deformation mechanics and is, therefore, able to quantify the observed kinematic patterns.
Understanding partitioning of deformation in highly arcuate orogenic systems: Inferences from the evolution of the Serbian Carpathians
2020, Global and Planetary Change
Citation Excerpt :
The Cretaceous formation of the Carpathian thick-skinned nappe stack was followed by a gradual clockwise rotation and N-, NE- to E-ward translation of the Tisza–Dacia mega-unit (e.g., Balla, 1987; Csontos, 1995; Márton, 2000; Pătraşcu et al., 1994; Panaiotu and Panaiotu, 2010; Ustaszewski et al., 2008). In respect to the stable European units situated in the foreland of the Carpathians, this Tisza–Dacia mega-unit underwent up to 90° of clockwise rotations during post-Cretaceous times (Pătraşcu et al., 1990, 1992, 1993; Panaiotu and Panaiotu, 2010), of which 15°-30° was achieved during post-middle Miocene times (de Leeuw et al., 2013; Dupont-Nivet et al., 2005). The amount of clockwise rotation decreases southwards to no significant rotations in the Balkanides during the Cenozoic (van Hinsbergen et al., 2008).
Highly curved orogens often demonstrate a complex poly-phase tectonic evolution and significant strain partitioning. While the oroclinal bending towards the outer arc is understood to be often driven by rapid slab roll-back, processes driving such bending towards the back-arc domain are less understood. The Serbian segment of the larger, highly bended Carpathians–Balkanides Mountains is one key example where we studied the kinematics of nappe stacking and the mechanics of oroclinal bending by the means of a field kinematic study correlated with available information in adjacent orogenic segments. Although not apparent in the large-scale structure of the Serbian Carpathians, our results demonstrate a poly-phase evolution, where the late Early Cretaceous nappe stacking was followed by Oligocene–middle Miocene ~40° of clockwise rotations. The superposition of Dinarides extension with the oroclinal bending in the Carpathians created overlapping stages of orogen-perpendicular extension and dextral strike-slip coupled with orogen-parallel extension, driven by the 100 km cumulated offset of the Cerna and Timok Faults. Extension was associated with the formation of Oligocene–Miocene basins, providing critical timing constraints for our kinematic study. These deformations were followed by the late Miocene E-ward thrusting of the Upper Getic sub-unit, which was driven by a transfer of deformation in the orocline and around the Moesian Platform during the last stages of Carpathians collision. These results show that the mechanics of oroclinal bending is associated with the activation of strike-slip faults and strain partitioning by bi-modal extension, enhanced by the overlap between different geodynamic processes.
Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic
2020, Gondwana Research
The basins and orogens of the Mediterranean region ultimately result from the opening of oceans during the early break-up of Pangea since the Triassic, and their subsequent destruction by subduction accommodating convergence between the African and Eurasian Plates since the Jurassic. The region has been the cradle for the development of geodynamic concepts that link crustal evolution to continental break-up, oceanic and continental subduction, and mantle dynamics in general. The development of such concepts requires a first-order understanding of the kinematic evolution of the region for which a multitude of reconstructions have previously been proposed. In this paper, we use advances made in kinematic restoration software in the last decade with a systematic reconstruction protocol for developing a more quantitative restoration of the Mediterranean region for the last 240 million years. This restoration is constructed for the first time with the GPlates plate reconstruction software and uses a systematic reconstruction protocol that limits input data to marine magnetic anomaly reconstructions of ocean basins, structural geological constraints quantifying timing, direction, and magnitude of tectonic motion, and tests and iterations against paleomagnetic data. This approach leads to a reconstruction that is reproducible, and updatable with future constraints. We first review constraints on the opening history of the Atlantic (and Red Sea) oceans and the Bay of Biscay. We then provide a comprehensive overview of the architecture of the Mediterranean orogens, from the Pyrenees and Betic-Rif orogen in the west to the Caucasus in the east and identify structural geological constraints on tectonic motions. We subsequently analyze a newly constructed database of some 2300 published paleomagnetic sites from the Mediterranean region and test the reconstruction against these constraints. We provide the reconstruction in the form of 12 maps being snapshots from 240 to 0 Ma, outline the main features in each time-slice, and identify differences from previous reconstructions, which are discussed in the final section.
Geodynamical models of lithospheric deformation, rotation and extension of the Pannonian Basin of Central Europe
2010, Tectonophysics
The two major crustal blocks of the Pannonian basin, Alcapa (Alpine–Carpathian–Pannonian) and Tisza, underwent a complex process of rotation and extension of variable magnitude during the Tertiary. The northward push of the Adriatic Block initiated the eastward displacement and rotation of both the Alcapa and Tisza blocks. We have constructed geodynamical models of the rotation and extension of the two Pannonian blocks. We analyse this process in terms of the competing influences of a NE push by the Adriatic block, a NE pull from a retreating subduction zone on the eastern Carpathians, and the internal buoyancy forces arising from crustal thickness variations. Deformation of the blocks included substantial strike-slip movements, together with shortening and possible extension across the Mid-Hungarian Line, which now separates the two domains. We use an idealised thin viscous sheet model of the continental lithosphere in which deformation is described by a nonlinear viscous constitutive relationship. Our approach is based on the finite element method, and we consider several distinct models of initial geometry, boundary conditions, and constitutive parameters. Rotation and deformation vary across both blocks, with anticlockwise rotation occurring in the Alcapa plate, and clockwise rotation in the Tisza block. The opposite rotations of the two plates led to NW–SE convergence in the space between the two Intra-Carpathian terranes. Subsequently both domains underwent extension dominantly in the NE–SW direction. Extension and internal rotation can be represented using a thin sheet model in which deformation is driven by an east- or northeast-directed outward traction of order 1 to 3 MPa. Internal buoyancy forces produced by thick crust from a prior phase of Alpine-style convergence appear to be a necessary element in the force balance that drives the extension process.
Palaeomagnetism of the Upper Cretaceous Sânpetru Formation (Haţeg Basin, South Carpathians)
2010, Palaeogeography, Palaeoclimatology, Palaeoecology
This paper reports on the palaeomagnetism of 10 localities from Upper Cretaceous sediments of the Sânpetru Formation exposed in the Haţeg Basin (South Carpathians, Romania). The Sânpetru Formation is one of the best exposed latest Cretaceous continental successions of Eastern Europe being famous for its unique assemblage of dinosaurs, mammals and other vertebrates. A total of 169 samples were collected from 66 strata through an 860-m-thick section. For most of the samples, the remanences were soft and/or noisy, forcing us to reject 63% of the collection. In the rest of the collection, both polarities are observed and inclination-only analysis indicates that pre-tilting remanence is preserved for many samples. These data, along with published palaeomagnetic results from the Haţeg Basin, pass a regional fold test. The palaeomagnetic study has provided an acceptable magnetostratigraphy which shows that the studied part of the Sânpetru Formation was deposited between the beginning of the Chron 32n.1n and the end of Chron 31n. These first palaeomagnetic results obtained from the Upper Cretaceous sedimentary rocks from the South Carpathians confirm the previous palaeomagnetic results obtained from magmatic rocks: the subtropical palaeolatitude during Late Cretaceous and the large clockwise rotation during the Tertiary.
High-K ankaramitic melt inclusions and lavas in the Upper Cretaceous Eastern Srednogorie continental arc, Bulgaria: Implications for the genesis of arc shoshonites
2009, Lithos
The Upper Cretaceous Yambol–Burgas region of the Eastern Srednogorie continental arc is characterized by unusually large volumes of mafic shoshonitic and ultra-K magmatism represented by high-Mg cumulitic rocks, and nepheline-normative ankaramites, absarokites and shoshonitic (high-alumina) basalts. The cumulitic rocks consist of phenocrysts of clinopyroxene and olivine (Fo_91–85) with inclusions of spinel (Cr#75–78). Olivine high-Fo cores and clinopyroxene host glassy melt inclusions which have nepheline-normative compositions with ankaramitic CaO/Al₂O₃ ratios (> 1), low SiO₂ (47.4–50.0 wt.%), high MgO (7.5–10.8 wt.%), high total alkalis and shoshonitic K₂O/Na₂O ratios (> 1). Electron microprobe and LA-ICPMS analyses demonstrate that parental magma was a high-Ca primitive mantle melt. Melt inclusions from the less Fo₈₅ rim approach absarokite composition with CaO/Al₂O₃ ratios < 1, lower MgO (5.2 wt.%), and higher total alkalis and K₂O/Na₂O ratio. The ankaramitic rocks are strongly porphyritic, composed of phenocrysts of altered olivine with spinel inclusions and large clinopyroxene. Their major and trace element compositions are similar to those of melt inclusions hosted in the high-Fo_91–90 cores and clinopyroxene of the cumulitic rock. The absarokites differ from the high-K ankaramites by slightly higher SiO₂ (50.6–52.7 wt.%), Al₂O₃ and alkali-oxide contents, lower FeO and MgO and particularly low CaO/Al₂O₃ (0.6–0.9) ratio. Compared to the absarokites, shoshonitic basalts have similar SiO₂ (50.2–52.8 wt.%) at lower MgO contents and CaO/Al₂O₃ ratios (0.37–0.53). The presented extensive set of major and trace element data on melt inclusions and whole rocks, along with their main phenocryst compositions, is used to constrain the crystallization temperatures and pressures of the most primitive ankaramites. We suggest that ankaramite compositions are formed by melting of a garnet-free metasomatized mantle source rather than by melting of lower crustal cumulates. Numerical modelling demonstrates that the generation of absarokites and shoshonitic basalts is compatible with fractionation of olivine and clinopyroxene from ankaramitic magma. The high-Mg chemistry of cumulitic rocks is explained as the result of accumulation of these minerals.

View all citing articles on Scopus

View full text

The paleomagnetism of the Upper Cretaceous magmatic rocks in the Banat area of South Carpathians: tectonic implications

Abstract

Earth Planet. Sci. Lett.

J. Geodyn.

Tectonophysics

Phys. Earth Planet. Inter.

Chem. Geol. (Isotope Geoscience Section)

Tectonophysics

Tectonophysics

Spatial distribution and structural images of Banatites from Romania deduced from gravity and magnetic data

Rev. Roum. Géol., Géophys. Géogr.-Géophys.

Instruments and measuring methods in paleomagnetic research

Meded. Verb. K.N.M.I.

The measurement of the anisotropy of the susceptibility with an astatic magnetometer

The Carpathian loop and the Pannonian Basin: a kinematic analysis

Geophys. Trans.

Paleomagnetic record of plate-margin tectonic processes along the western edge of North America

J. Geophys. Res.

Zăcăminte minerale şi tectonica globală

Cooper mineralizations related to Upper Cretaceous-Paleogene magmatites in Romania

Rev. Géol., Géophys. Géogr.-Géol.

Magnetic polarity stratigraphy of the Tertiary igneous rocks of Skye, Scotland

Geophys. J. Int.

Error analysis for the determination of tectonic rotation from paleomagnetic data

J. Geophys. Res.

Determination of the magnetic polarity of rock samples in the field

U.S. Geol. Surv., Prof. Pap., 450-D

Dispersion on a sphere