bluuebunny/crossref_metadata_2025_split huggingface dataset:
Large scale rotations in North Hungary during the Neogene as indicated by palaeomagnetic data
Authors: Márton Emő , Márton Péter 
Published: April 2008

Abstract
Tertiary igneous and sedimentary rocks were collected for palaeomagnetic study at about 90 localities from the North Hungarian Central Range. Rock ages range from the late Eocene to the Mid-Miocene but the majority of the samples are Early Miocene in age.
After laboratory treatment 66 localities yielded palaeomagnetic results, which fall into two groups. The first group is characterized by a westerly declination rotation of 70–90° accompanied by shallowed inclinations, and the second group is characterized by a declination rotation of only 30° in the same sense. The first group is older and comprises rocks of late Eocene to early Miocene age, whereas the second group comes from rocks of late Ottnangian to Karpatian age. These results are indicative of two successive tectonic rotations, one in the late Ottnangian and another just preceding the Badenian. The first rotation was accompanied by a northward shift of the area.
Palaeomagnetism and palaeogeography of the Western Carpathians from the Permian to the Neogene
Authors: Krs Miroslav , Krsová Marta , Pruner Petr 
Published: April 2008

Abstract
Geodynamic models for the Western Carpathians require evaluation of palaeomagnetic data from the Outer Carpathian flysch belt, from limestones of the Klippen Belt and from volcanic and sedimentary rocks of the Inner Carpathians. Palaeomagnetic data for the Permian to the Neogene are evaluated. The data indicate marked, mostly anticlockwise tectonic rotations of larger rock complexes and nappes. The distribution of palaeomagnetic poles is characteristic of a collision zone, and crosses the apparent polar wandering path for the African plate. Tectonic rotations are observed in both the Inner Carpathians and the Klippen Belt as well as in the Outer Carpathian flysch belt. Most drift occurred during the Permian to Triassic interval, with northward movement from initial southern equatorial latitudes. Drift decelerated from the Jurassic to the Neogene.
Ultra-fine magnetostratigraphy of Cretaceous shallow water carbonates, Monte Raggeto, southern Italy
Authors: Iorio M. , Tarling D. H. , D’argenio B. , Nardi G. 
Published: April 2008

Abstract
The sedimentological and palaeomagnetic parameters of bore cores of shallow-water Hauterivian and Barremian carbonates have been defined at 1 cm and 2 cm intervals, respectively. The stability of remanence to alternating fields has been established and a composite 88 m sequence compiled. This shows fine structure polarity changes, with the Hauterivian section being almost entirely of Normal polarity and the Barremian including thick zones of both predominantly Normal and Reversed polarity. Narrow zones of opposite polarity occur throughout. The sedimentological and palaeomagnetic properties are found to exhibit clear cyclicities, which, when normalized, show an extremely high correlation to each other and to the predicted orbital variations for this period. This enables a study of polarity transitions and secular variations using a chronology in which 1 cm is equivalent, on average, to 285 ± 8 years.
Revised magnetostratigraphy and rock magnetism of Pliocene sediments from Valle Ricca (Rome, Italy)
Authors: Florindo F. , Sagnotti L. 
Published: April 2008

Abstract
This is an extended abstract of the paper ‘Palaeomagnetism and rock magnetism in the upper Pliocene Valle Ricca (Rome, Italy) section’ by Florindo & Sagnotti (1995). It is shown that a normal polarity event reported from a sedimentary section in the Tini quarry is associated with a different mineralogy than the rest of the sequence. Combined thermal and AF demagnetization reveals that there is a pervasive reversed polarity component throughout the sequence, but this is obscured by a strong normal component in sediments close to an ash bed. A variety of techniques show that the reversed component is carried by magnetite and likely to be primary. The normal component is associated with greigite and is likely to be of late diagenetic origin or possibly associated with self-reversal behaviour. The previous correlation between the normal polarity zone and the Reunion Event is therefore invalid and the entire sequence is considered to correlate with the C2r. 1r chron, between the Olduvai and Reunion Events.
Palaeomagnetic database: the effect of quality filtering for geodynamic studies
Authors: Scalera Giancarlo , Favali Paolo , Florindo Fabio 
Published: April 2008

Abstract
The Global Palaeomagnetic Database (GPMDB), now updated to 1992, contains about 7000 palaeomagnetic data, which are fundamental tools to define regional and global geodynamic models. A software developed at the Istituto Nazionale di Geofisica allows the selection of data on the basis of space, time, and quality. Six quality classes have been proposed. The African and European Apparent Polar Wander Paths (APWPs) have been computed and the role of the statistical uncertainties is discussed. Some examples from the Tethys Belt have been chosen to demonstrate the effect of the quality filtering in geodynamic studies.
Palaeomagnetism as a tool for testing geodynamic models in the North Aegean: convergences, controversies and a further hypothesis
Authors: Kondopoulou D. , Atzemoglou A. , Pavlides S. 
Published: April 2008

Abstract
The north Aegean region is a geologically complicated area, in which numerous studies have focused during the last decade. Palaeomagnetism can give a decisive contribution in selecting possible models. In the present study all available palaeomagnetic data from the north Aegean and surrounding area (39.5°N to 42°N and 20°E to 26°E) are compiled, classified and evaluated. Their significance in terms of the rotational behaviour is given as follows.

In various plutonic, volcanic (Eocene-Oligocene) and sedimentary (Mio-Pliocene) formations, systematic easterly declinations are observed. The rare exceptions are caused either by remagnetized material or by very local phenomena. The declination gradually increases from recent to older periods, varying between approximately 20° and 40°. This distribution is seen in the area between south Albania and the western Greek Rhodope. In contrast, the eastern Greek Rhodope appears to be unrotated. The inclinations diverge systematically from the expected values. This could be due to either an alternative pole position for the Eocene (Westphal 1993) or possible tilting of blocks during the Oligocene-Miocene, associated with a NE-SW brittle-ductile extensional stress field. The data partially confirm geodynamic models proposed for the area by Taymaz
et al.
(1991), Sokoutis
et al.
(1993) and Jolivet (1993). The model proposed by Dinter & Royden (1992) does not predict rotations and is not supported by the palaeomagnetic data.

When the published volcanological, structural, seismic and palaeomagnetic data are combined they suggest that the north Aegean region during the Early Tertiary was tectonically similar to the present day active south Aegean subduction zone.
Palaeomagnetic study of crustal deformation across an intracontinental transform: the North Anatolian Fault Zone in Northern Turkey
Authors: Piper J. D. A. , Moore Joanna M. , Tatar O. , Gursoy H. , Park R. G. 
Published: April 2008

Abstract

Eocene volcanic rocks spanning the North Anatolian Fault Zone in north central Turkey have a common reversed polarity and appear to record a short term volcanic episode useful for identifying subsequent tectonic rotations. Although regional differences are present, no distributed clockwise rotations caused by dextral motion across the fault zone since mid-Miocene times are found. Instead variable anticlockwise block rotations demonstrate that this fault system does not obey theoretical models for crustal behaviour across continental transforms. Deformation is found to be highly inhomogeneous with a narrow zone of intense clockwise rotation recognised within blocks bounded by strike-slip faults above, and parallel to, the fundamental lineament. Further from the lineament no systematic rotations with respect to the major bounding plates are detected. A zone of
c.
30° anticlockwise rotation in the east may be either a consequence of emplacement of the Pontides or an ongoing consequence of continental collision. Slightly larger rotations south of the fault probably record block rotations into Anatolia as this region is being extruded westwards by continuing impingement of Afro-Arabia into the Eurasian Plate.
Palaeomagnetism of some Tertiary sedimentary rocks, southwest Sinai, Egypt, in the tectonic framework of the SE Mediterranean
Authors: Abdeldayem A. L. , Tarling D. H. 
Published: April 2008

Abstract
Two hundred and fifteen limestone core samples of Palaeocene (nine sites), Lower Eocene (ten sites) and Miocene (nine sites) ages were collected from the Wadi Feiran area, southwest Sinai. The majority of samples contained magnetic vectors that were consistent in direction during thermal and alternating field demagnetization. Normal and reversed polarities were identified that passed a reversal test, but the bedding tilts were too small to enable an adequate fold test to be undertaken. When compared to coeval palaeomagnetic poles for stable Africa, the Sinai palaeomagnetic poles are consistently displaced by some 30°. This is unlikely to be due to crustal translation between Sinai and Africa, but is attributed to local tectonic rotations of fault blocks in a similar way as for other areas in the SE Mediterranean. In the Suez area, the rotation has been mainly about horizontal axes and is associated with the opening of the Gulf of Suez.
Archaeomagnetic results from the Mediterranean region: an overview
Authors: Evans M. E. 
Published: April 2008

Abstract

Palaeomagnetic methods were first applied to archaeological materials and very young geological formations in the Mediterranean region a century and a half ago. Although the pioneering work established the general validity of the method, the data remained sparse and permitted only limited conclusions. By the mid-1920s, thorough investigations of the lava flows of Mt. Etna demonstrated how geomagnetic secular variation could be traced back into pre-observatory epochs. In the following decade, systematic study of archaeological features commenced, but it was not until the 1960s that the database had grown to the point where useful geomagnetic inferences could be drawn. For the Mediterranean region, there are currently available two extensive data sets (one for France, the other for Bulgaria) containing a total of
c.
400 directional results. For Italy and Greece, a useful start has been made (
c.
100 results); for other countries (Morocco, Tunisia, Turkey) only a handful of results have been published. Collectively these data enable us to trace back the directional behaviour of the geomagnetic field with resonable confidence for the last 2000 years, but with less certainty for earlier times. Nevertheless, a picture is emerging in which static flux bundles and flux spots undergoing zonal retrograde drift can be recognized. Since the determination of geomagnetic field strength does not require
in situ
material, the investigator is freed of the need for accurately oriented samples and the scope of archaeomagnetic research is therefore enlarged. Many results have been published, but their status remains questionable due to the on-going debate concerning the validity of the different experimental procedures. Intensity and directional results have potential for archaeological dating both in an absolute and in a relative sense. Some authors claim the possibility of achieving a precision approaching ±50 years, but this depends strongly on the region and time interval in question. One example of particular interest is the application of archaeomagnetic data to the demise of the Minoan civilization.
Collision and strike-slip faulting in the northern Molucca Sea (Philippines and Indonesia): preliminary results of a morphotectonic study
Authors: Rangin Claude , Dahrin Daharta , Quebral Ray ,   The Modec Scientific Party
Published: April 2008

Abstract

A swath mapping, gravity and single channel seismic survey was carried out in the northern Molucca Sea with R.V.
L’Atalante
. Preliminary interpretation of these data reveals the presence of an almost complete Sangihe arc and forearc. The Miangas-Pujada-Talaud ridge in the central part of the Molucca Sea appears to be a backstop within the Sangihe forearc. East of the ridge very contrasting terranes are separated by a major NW-SE crustal discontinuity interpreted as a left-lateral strike-slip fault. North of 6°N the Philippine Trench inner wall is dissected by NW-SE trending left-lateral strike-slip faults, resulting from the dominantly oblique convergence between colliding arcs. South of 6°N the westward subduction of the buoyant Snellius volcanic plateau, a fragment of the Halmahera arc terrane, has induced the formation of a new plate boundary, the Philippine Trench along what is interpreted as a former strike-slip fault zone. East of the Miangas-Pujada-Talaud ridge there is a wide sedimentary wedge separated from the Snellius Ridge to the south by the major NW-SE crustal discontinuity. The thickness of this wedge cannot be explained by subduction along the very young Philippine Trench. It could be either an accretionary wedge developed at the deformed leading edge of the Sangihe forearc or be part of a former intra-arc basin which was part of the colliding Halmahera arc terrane. There is no clear evidence for accreted oceanic crust belonging to the recently subducted Molucca Sea. The Miangas-Pujada-Talaud ridge is part of the Sangihe forearc, and the ophiolites could represent its basement, uplifted along the outer arc ridge. The dog-leg-shaped Philippine Trench is propagating southward across the fragmented Halmahera arc terrane and its southern segment could reactivate a former strike-slip fault zone.
Detailed processing of seismic reflection data from the frontal part of the Timor trough accretionary wedge, eastern Indonesia
Authors: Hughes B. D. , Baxter K. , Clark R. A. , Snyder D. B. 
Published: April 2008

Abstract
The DAMAR deep seismic line across the Banda arc in Indonesia provides a valuable insight into the Late Cenozoic collision between the northward-moving Australian plate and the Southeast Asian plate. Previous geophysical investigations across the accretionary wedge have only imaged relatively shallow structures due to the complex structure of the wedge which remains poorly resolved following conventional processing techniques. The design of a detailed processing sequence and its application to a 35 km section of the DAMAR line to include the Australian Northwest shelf, the Timor trough and the frontal part of the accretionary wedge, has allowed an improvement in resolution of structures both within and below the frontal part of the wedge. The Australian margin to the south of the trough contains a number of normal faults which show inversion features. The reprocessing of the accretionary wedge has allowed an improved interpretation of the internal structure in the frontal part of the collision zone and this consists of a number of high angle thrust structures. This has shown that shortening in the frontal part of the accretionary wedge has developed coherent thrust slices imbricated from the subducting Australian margin, rather than an incoherent melange.
Cenozoic SE Asia: reconstructing its aggregation and reorganization
Authors: Packham Gordon 
Published: April 2008

Abstract
Reconstructing SE Asia in the Cenozoic is dependent on being able to model three major tectonic events and their consequences. They are the collision of India with Eurasia, the rotational history of the Philippine Sea plate and the ongoing collision of Australia with eastern Indonesia. Models of the Eocene India-Eurasia collision imply extrusion along major strike-slip faults or crustal thickening and block rotation. Kinematic modelling of the present day tectonics of central Asia indicates rotations and strike-slip faulting and an eastward displacement of crust. Prior to middle Miocene time tectonic activity was closely associated with the collision zone and extrusion of Indochina was supposed to have occurred. Analysis of the volume of the topography formed by the collision indicates eastward displacement and the loss of some crust by expulsion or into the mantle. Palaeomagnetic measurements have found northward displacement of Tibet and strong clockwise rotation east of the eastern syntaxis but unequivocal evidence of southward displacement is rare. Large Palaeogene to early Neogene displacements on strike-slip faults have been documented and related with confidence to the rotations that formed at least the Oligocene South China Sea floor. Early Oligocene docking of the Indoburman Flysch belt south of the eastern syntaxis is difficult to explain in extrusion models. Whether the rotations that have been documented are a response by internal deformation or block rotation is unresolved, as is the amount of extrusion of SE Asia to the south. In the eastern region, rotation and associated northward motion of the Philippine SEa plate as it developed puts constraints on possible models because of a maintained close proximity of its southern margin to the northern edge of the Australian craton. Assembling of continental fragments now in the Banda Sea and derived from eastern New Guinea appears to have occurred by Late Cretaceous time. Formation of the Banda arc may have isolated the Banda Sea from the Australia plate then collision of the Australian margin possibly rotated the Banda Sea counter-clockwise. Although westward movement of the Philippine Sea plate relative to Australia commenced in the early Miocene, convergent left-lateral shear was not possible until the late Miocene thus limiting westward tectonic transport of terranes and the transmission of the shear into the region west of the Banda Sea.
Timing of the Shan-Thai-Indochina collision: new evidence from the Pak Lay Foldbelt of the Lao PDR
Authors: Stokes Robert B. , Lovatt Smith Paul F. , Soumphonphakdy Ko 
Published: April 2008

Abstract
The Pak Lay Foldbelt in the northwest of the Lao PDR is a product of the Indosinian orogeny, resulting from the collision of Shan-Thai and Indochina along a suture now marked by the Nan-Uttaradit ophiolite zone. Current hypotheses place the timing of this collision in either the Permian or the Triassic. Recent field work and subsequent laboratory analyses suggest that, in the area to the south of Pak Lay: pre-collision sediments are as young as Middle to Upper Jurassic; arc-related volcanism continued from the Triassic into the Late Jurassic; all these sediments and volcanic rocks form an imbricate zone; and the Cretaceous Khorat Group rests with marked unconformity above the imbricate wedge. From this we conclude that the Shan-Thai-Indochina suturing occurred in the Late Jurassic.
Mid-Cretaceous inversion in the Northern Khorat Plateau of Lao PDR and Thailand
Authors: Lovatt Smith Paul F. , Stokes Robert B. , Bristow Charlie , Carter Andrew 
Published: April 2008

Abstract
Evidence is presented from the study area for the occurrence of a regional compressive tectonic event in the mid-Cretaceous (Aptian-Cenomanian). This is tentatively attributed to the effects of a distant continent-continent collision to the west. Pre-existing structural trends were reactivated parallel to palaeo-continental sutures to the northeast (Song Ma and Song Da) and west (Nan). The event interrupted the latest Jurassic to earliest Palaeocene subsidence and continental sedimentation of the Khorat Plateau Basin. The primary effects are shown by seismic data to be regional tilting, compressive folding, reverse faulting and inversion of the basin subsidence pattern. The data do not support the current view that such structuring was initiated during the Tertiary. However they do show that there was some reactivation of mid-Cretaceous structures during regional uplift in the Tertiary. This revision of timing of structuring suggests the hydrocarbon potential of the area may be greater than previously anticipated.
Origin and tectonic significance of the metamorphic rocks associated with the Darvel Bay Ophiolite, Sabah, Malaysia
Authors: Omang Shariff A. K. , Barber A. J. 
Published: April 2008

Abstract
Banded hornblende gneiss, foliated amphibolite, hornblende, chlorite and siliceous schist form lenses in an 8 km wide belt within the Darvel Bay Ophiolite Complex. Foliation in the belt is generally steep to vertical, striking parallel to the trend of the belt and lineations are sub-horizontal. Mineral and geochemical studies show that the metamorphic rocks represent banded and isotropic gabbros, plagiogranites, doleritic and basaltic dykes, basaltic volcanics and cherts formed at a spreading ridge in a supra-subduction zone environment, which were deformed at high temperatures but low pressures along a transform fault. Incorporation of supracrustal cherts indicates that the transform extended for hundreds of kilometres between spreading centres. Garnet pyroxenites and amphibolites found as clasts in Miocene volcanic agglomerates formed at high pressures, and temperatures are interpreted as derived from a metamorphic sole underlying the complex, formed during subduction of ocean crust and the emplacement of the ophiolite complex on Sabah.
The Tertiary evolution of South Sulawesi: a record in redeposited carbonates of the Tonasa Limestone Formation
Authors: Wilson Moyra E. J. , Bosence Dan W. J. 
Published: April 2008

Abstract
South Sulawesi, situated at the junction of three major plates and with an almost complete Tertiary sequence, is an ideal location in which to study syntectonic sedimentation. Redeposited carbonate facies of the lower/middle Eocene to middle Miocene Tonasa Limestone Formation in the Barru area prove to be reliable indicators of tectonic activity. South of the Barru area contemporaneous carbonate sediments formed on a relatively stable shallow-water platform, known as the Tonasa Carbonate Platform. Redeposited carbonate facies and interbedded marls from the Barru area are described and interpreted in this study. The immaturity and provenance of clasts indicate that the redeposited facies were derived from the faulted northern margin of the Tonasa Carbonate Platform. A relay ramp between at least two major NW-SE trending faults is the inferred configuration of this margin. Three main phases of faulting are indicated by the redeposited facies: late Eocene to early Oligocene, middle Oligocene and early to middle Miocene. This is consistent with other outcrop and seismic data from the region and with the inferred plate tectonic situation during the Tertiary.