bluuebunny/crossref_metadata_2025_split huggingface dataset:
The geological development of the Balkan Peninsula related to the approach, collision and compression of Gondwanan and Eurasian units
Authors: Karamata Stevan 
Published: April 2008

Abstract
The Balkan Peninsula includes the margins of both Eurasia (the Moesian microplate) and Gondwana (the Adria microplate as a promontory); it also includes ophiolitic belts that represent remnants of Tethys and its marginal seas. Various terranes docked to larger crustal units and were incorporated to form new units. Most units within the Balkan Peninsula moved northwards to their present positions, jointly or independently, from positions around, or south of, the Equator from the end of the Palaeozoic to the present day. The assembly of these units was associated with generally northeastward subduction of Tethys. The first main period of docking was in the Carboniferous. Later, from the Permian to the Maastrichtian, marginal seas opened and later closed. Island arcs formed within the northwestern part of Tethys, and parts of continental margins were detached and relocated, or were transported along transcurrent faults. In the Maastrichtian the entire oceanic area was closed and the main units sutured. The resulting assemblage later underwent additional compression, rotation and transcurrent displacement of some units.
Biochronology of Jurassic and Early Cretaceous radiolarites from the Lycian Mélange (SW Turkey) and implications for the evolution of the Northern Neotethyan ocean
Authors: Danelian T. , Robertson A. H. F. , Collins A. S. , Poisson A. 
Published: April 2008

Abstract
New radiolarian ages for blocks of radiolarian cherts associated with other blocks of distal pelagic facies and ophiolitic lithologies within the Lycian Mélange, SW Turkey, indicate deposition during Mid-Jurassic to Early Cretaceous time. Radiolarites overlying pink pelagic limestones of an allochthonous carbonate unit accumulated during the Mid- to Late Jurassic. On the basis of structural evidence the Lycian Mélange is inferred to have been rooted within the Northern Neotethys, to the north of the Tauride-Anatolide microcontinent. The Lycian radiolarites can be compared with other dated radiolarites from the Izmir-Ankara suture, the root zone of the Northern Neotethyan ocean. Based on all the available radiolarian data it is inferred that radiolarites accumulated within the Northern Neotethys in western Turkey from Late Triassic (Mid-Carnian to Late Norian) to Mid-Cretaceous (Cenomanian) time. The radiolarites were later detached from their inferred oceanic basement and accreted within a subduction complex during the Late Cretaceous (Turonian-Maastrichtian) and emplaced over the northern margin of the Tauride-Anatolide continent together with slices of continental margin and ophiolitic lithologies.
Cumulates and gabbros in southern Albanian ophiolites: their bearing on regional tectonic setting
Authors: Koller F. , Hoeck V. , Meisel T. , Ionescu C. , Onuzi K. , Ghega D. 
Published: April 2008

Abstract
The western belt of the southern Albanian ophiolites consists of six major ophiolite massifs (Voskopoja, Rehove, Morava, Devolli, Vallamara, Shpati) and two smaller ones (Luniku and Stravaj). Each massif has a distinct sequence of mantle tectonites, ultramafic cumulates (plagioclase-bearing peridotites and wehrlites), cumulate gabbros, troctolites and isotropic gabbros. Voskopoja, Rehove and Morava have predominantly lherzolites as mantle tectonites, Shpati lherzolites and harzburgites, and Devolli and Vallamara almost exclusively harzburgites. A volcanic section together with volcanogenic sediments occurs only in the Voskopoja and Rehove massifs as well as in the smaller Luniku and Stravaj massifs. Whole-rock geochemistry and mineral chemistry suggest a mid-ocean ridge setting for the origin of the cumulates and gabbros from the Voskopoja, Rehove and Morava massifs, with only a minor suprasubduction zone (SSZ) influence. The Shpati massif and the small Luniku massif show mid-ocean ridge (MOR) and SSZ signatures in their plutonic sequences. Cumulates and gabbros from Devolli and Vallamara formed in an SSZ setting. The predominance of MOR-generated crustal rocks and the relatively minor occurrence of SSZ-generated plutonic rocks together with the volcanogenic sediments in the Voskopoja and Rehove massifs are indicative of a back-arc basin origin of the western belt ophiolites above a westward-dipping subduction zone.
Palaeomagnetic insights into the evolution of Neotethyan oceanic crust in the eastern Mediterranean
Authors: Morris Antony , Anderson Mark W. , Inwood Jennifer , Robertson Alastair H. F. 
Published: April 2008

Abstract

A synopsis of palaeomagnetic data from three Late Cretaceous eastern Mediterranean Tethyan ophiolites (Troodos, Hatay and Baër-Bassit) and their sedimentary cover sequences is presented. These data provide valuable insights into the role of regional- and local-scale tectonic rotations in the geodynamic evolution of Neotethyan oceanic crust. The geologically earliest phases of tectonic rotation are documented in the Troodos ophiolite, where rotations around both subvertical and subhorizontal axes are readily related to the development of the spreading fabrics and structures during crustal genesis. Subsequent
c.
74° antickockwise intra-oceanic rotation of a ‘Troodos microplate’ has been quantified through analysis of the
in situ
sedimentary cover of the Troodos ophiolite. Results indicate that bulk anticlockwise rotation began soon after the cessation of spreading and ended by the end of the Eocene, with
c.
50–60° of microplate rotation being over by the Maastrichtian, the time at which ophiolite thrust sheets were emplaced onto the Arabian continental margin to the east of Troodos. Recent results from the emplaced, structurally dismembered Baër-Bassit ophiolite indicate extreme anticlockwise rotations of ophiolitic thrust sheets varying on a kilometre scale. New data from the post-emplacement sedimentary cover confirm that only a small component of these rotations is due to post-emplacement tectonism. Baër-Bassit represents the leading edge of the emplaced ophiolitic sheet. New data from the more coherent section preserved in the Hatay ophiolite to the north demonstrate significant anticlockwise rotation. This is equivalent to the rotation of the most northerly part of the Baër-Bassit units to the south, and is of the same sense and magnitude as the pre-Maastrichtian phase of microplate rotation documented in the Troodos. This suggests a common, intra-oceanic origin for the majority of the Troodos and Hatay rotations, and a significant component of the more variable rotations observed in Baër-Bassit. Overall, therefore, the data support a model involving: (1) intra-oceanic rotation of a coherent region of crust within the southern Neotethyan basin; this rotated unit is more areally extensive than has previously been inferred from consideration of data from the Troodos ophiolite alone; (2) emplacement of part of the rotated unit onto the Arabian platform; (3) subsequent localized post-emplacement modification, related to the development of the current plate configuration.
The wide distribution of HP-LT rocks in the Lycian Belt (Western Turkey): implications for accretionary wedge geometry
Authors: Rimmelé Gaëtan , Oberhänsli Roland , Candan Osman , Goffé Bruno , Jolivet Laurent 
Published: April 2008

Abstract
In SW Turkey, Fe-Mg-carpholite has recently been recognized in the basal metasediments of the Lycian Nappes, which overthrust the Menderes Massif on its southern flank. This high-pressure-low-temperature (HP-LT) metamorphic index mineral was widely found in the Bodrum peninsula region. Our new metamorphic and structural data on similar carpholite-bearing rocks found farther north in several klippen of the Lycian Nappes located on top of the Menderes Massif show that HP-LT rocks in SW Turkey occur over a distance of >200 km in both north-south and east-west directions, thus indicating a wide HP-LT metamorphic belt. The deformation pattern from the Bodrum peninsula to Çivril, all along the contact between the Lycian Nappes and the Menderes Massif, reveals the role played by major top-to-the-NE shear zones contemporaneous with exhumation of the Lycian HP-LT rocks. This deformation shows an oblique direction of opposite shear sense relative to the earlier southward translation of the Lycian Nappes over the Menderes Massif, for which top-to-the-south displacements are preserved in the upper units of the Lycian Nappes on the Bodrum peninsula, as well as at the base of the Lycian nappe klippen located farther north. The widespread distribution of well-preserved Fe-Mg-carpholite-bearing rocks in the Lycian Nappes has implications for the geometry of the accretionary wedge responsible for HP-LT metamorphism in SW Turkey.
A new orogenic model for the External Hellenides
Authors: Doutsos T. , Koukouvelas I. K. , Xypolias P. 
Published: April 2008

Abstract
In the context of the External Hellenides, ‘pro’-lithosphere, corresponding to the Apulian microcontinent, converges on ‘retro’-lithosphere, corresponding to the Pelagonian microcontinent. Structural and stratigraphic data in the External Hellenides suggest that the convergence at this margin is fairly well described by the conceptual doubly vergent accretionary wedge model. This new orogenic model for the External Hellenides differs from the classical west-verging assumption and emphasizes that the retro-mass flux is critical for the pro-mass flux. Our model is primarily 2D, and is described in terms of three system components: an accretionary wedge (or pro-wedge), an uplifted plug and a retro-wedge. Three ‘isopic’ zones (Pindos, Gavrovo-Tripolitsa and Ionian) are included in the pro-wedge. The uplifted plug in the north (Epirus area) includes the Pindos ocean ophiolitic rocks and the Pindos zone, the Parnassos zone in central Greece, and the HP belt of the External Hellenides in the Peloponnese. The retro-wedge includes the Mesohellenic Trough in the north and the Argos plain in the south.
Evidence for late Holocene activity along the seismogenic fault of the 1999 Izmit earthquake, NW Turkey
Authors: Pavlides S. B. , Chatzipetros A. , Tutkun Z. S. , Özaksoy V. , Doğan B. 
Published: April 2008

Abstract

During the strong 1999 Izmit (Kocaeli) earthquake, 100 km long east-west-striking (N80°–100°), right-lateral, fault traces were formed. In the epicentral area the seismic ruptures did not follow any known or mapped fault traces, but morphology and tectonostratigraphic evidence from trenches reveal pre-existing earthquake-related features, e.g. elongated valleys, shutter ridges, high-angle slopes, scarplets and stream offsets. In the Gölcuk Peninsula a characteristic NW-SE-trending extensional fault segment emerged at the surface with a 1.5–2 m maximum vertical displacement and a 0.30 m right-lateral component. The resulting coseismic fault scarp was mapped in detail, and two trenches were excavated at the Dëniz Evler site. The 1999 displacement at this site was 1.50 m, whereas the penultimate event displaced the same sediments by 0.70 m, and a previous event by 0.20 m. Displacement is not characteristic, as fault-associated soft (recent) deltaic deposits, and the fault itself, are typically not coseismic, but rather a secondary accommodation structure in geometric consistency with the right-lateral main displacement zone. The data were compared with similar results from the Aşãgı Yuvacik, Kular Yaylacik and Acisu sites between Izmit and Sapanca Lake. The same fault segment seems to have been activated and produced surface ruptures including during the earthquakes of
AD
1509,
AD
989 and
AD
554, plus two prehistoric events. The palaeoseismological results provide clear evidence for repeated reactivation of the same fault or fault segments during historical seismic events.
Flow in multiscale fractal fracture networks
Authors: Davy P. , Bour O. , De Dreuzy J.-R. , Darcel C. 
Published: April 2008

Abstract
The paper aims at defining the flow models, including equivalent permeability, that are appropriate for multiscale fracture networks. As a prerequisite of the flow analysis, we define the scaling nature of fracture networks that is likely quantified by power-law length distributions whose exponent fixes the contribution of large fractures versus small ones. Despite the absence of any characteristic length scale of the power-law model, the flow structure appears to contain three length scales at the very maximum: the connecting scale, the channelling scale, and the homogenization scale, above which the equivalent permeability tends to a constant value. These scales, including their existence, depend on the fracture length distribution and on the transmissivity distribution per fracture. They are basic in defining the flow properties of fracture networks.
‘Verrucano’ and ‘Pseudoverrucano’ in the Central-Western Mediterranean Alpine Chains: palaeogeographical evolution and geodynamic significance
Authors: Perrone V. , Martín-Algarra A. , Critelli S. , Decandia F. A. , D’Errico M. , Estevez A. , Iannace A. , Lazzarotto A. , Martín-Martín M. , Martín-Rojas I. , Mazzoli S. , Messina A. , Mongelli G. , Vitale S. , Zaghloul M. N. 
Published: April 2008

Abstract
The Anisian-Carnian Verrucano Group of the Tuscan Metamorphic Units and the Triassic-Hettangian Pseudoverrucano Formation of the homonymous unit are mainly continental redbeds occurring in Tuscany at the base of the Alpine orogenic cycle. A study carried out throughout the Apennine, Maghrebian and Betic Chains emphasized the presence in all these orogenic belts of deposits more or less coeval and similar both to the metamorphic Verrucano and to the unmetamorphosed Pseudoverrucano. Thus, the distinction of Verrucano and Pseudoverrucano successions has a palaeogeographical and geodynamic importance at the scale of the Western Mediterranean. Both successions developed during the continental rift stage of Pangaea, which led to later break-up at the edges of a future microplate, interposed between the Europe, Africa and Adria-Apulia plates, but they are characterized by different tectonometamorphic evolution. Pseudoverrucano-like deposits, devoid of Alpine metamorphism, characterize the highest tectonic units of the nappe stack and they overthrust units bearing Verrucano-like deposits. These latter show an Alpine tectonometamorphic history marked during the Miocene by intense deformation and HP/LT metamorphism (at pressures in the range of 0.8–2 GPa), followed by a retrograde phase associated with decompression, suggesting subduction and subsequent exhumation of continental crust. Intriguing palaeogeographical problems arise from the analysis of Verrucanobearing units, because the same evolution seems to characterize both units considered to belong to a realm similar to that of the north-verging Austroalpine nappe system and some units referred to the south-verging fold-thrust belt derived from the Adria-Apulia palaeomargin.
Recent palaeostresses from striated pebbles related to fold development in a mountain front: the Prerif Ridges (Rif Cordillera, Morocco)
Authors: Ruano P. , Bargach K. , Galindo-Zaldívar J. , Chalouan A. , Ahmamou M. 
Published: April 2008

Abstract
The southern mountain front of the Rif Cordillera (Morocco) provides impressive geological evidence of the most recent deformations related to the activity of the Eurasian-African plate boundary in the Western Mediterranean. In this region, striated and pitted pebbles are analysed from Pliocene-Quaternary rocks located in the southern front of the Prerif Ridges, which have been deformed by south-vergent folds of decametre to hectometre sizes. Striated and pitted pebbles represent a tectonic deformation structure which, although very scarce in nature, is revealed as one of the most complete for determining palaeostresses. In Jbel Trhat and Jbel Zerhoun of the Rif mountain front, north-south to NNW-SSE prolate compression stress ellipsoids are related to an initial stage of south-vergent fold development during the progressive tilting of conglomerate layers. Finally, oblate stress ellipsoids indicate extension parallel to the fold axes. The north-south trend of the determined compression is compatible with a tectonic setting where the NW-SE convergence of the Eurasian and African plates is modified by the westward motion of large crustal blocks such as the Alboran Domain or the southwestward motion of blocks in the Rif Cordillera.
Geophysical and geological interpretation of discrepancies in site residuals in northern Morocco: a simple qualitative approach
Authors: Ait Brahim L. , Mouayn I. , Abdelouafi A. , Benhalima M. , Tadili B. 
Published: April 2008

Abstract

Surface geology, gravimetric, and heat flow data are used to explain discrepancies between

M
D

site residuals, using the average magnitude site residuals (

AMSR
j

) which are opposite of the station corrections (

cSta
j

) calculated for the 25 selected short-period seismic stations of the Moroccan seismological network.

M
D

site residuals range from −0.29 to +0.32, and appear to be the result of the complex interaction of the predominant near-station geophysical and geological parameters. With this simple qualitative approach, we found that high negative residuals are obtained for older well-consolidated Precambrian crystalline rocks with low surface heat flow, and high positive residuals are attributed to recent unconsolidated sediments with high heat flow. The explanation for the intermediate residual values remains more complex and requires more accuracy and better quality data, and may not be fully justified in this study.
Factorial correspondence analysis: a useful tool in palaeogeographical reconstructions; example from late Cretaceous calciturbidites of the northwestern External Rif (Morocco)
Authors: El Kadiri Kh. , El Kadiri K. , Chalouan A. , Bahmad A. , Salhi F. , Liemlahi H. 
Published: April 2008

Abstract
Factorial correspondence analysis proved to be a useful statistical tool when comparing the clastic input of distinct deposits and searching for their source area. Here we analyse and compare the reworked carbonate clastic material in the late Cretaceous calciturbidites of the Béni Ider area (Rifian External Domain) and the Internal Dorsale Calcaire (Internal Domain). The main result is that the source area for the Béni Ider calciturbidites was a neighbouring, isolated, shallow carbonate platform, the basement of which consists of a Jurassic succession of the Internal Dorsale Calcaire type. However, statistical comparison with the coeval pelagic deposits of to the latter domain leads us to exclude the Dorsale Calcaire as a possible origin of these Béni Ider calciturbidites. The source area was probably a lost carbonate platform, which should be located in the open External Domain. This result appears to be consistent with the Tariquide Ridge hypothesis and gives new insights into the palaeogeographical scheme of the flysch trough.
Fault and fold interaction during the development of the Neogene-Quaternary Almería-Níjar basin (SE Betic Cordilleras)
Authors: Pedrera Antonio , Marín-Lechado Carlos , Galindo-Zaldívar Jesús , Rodríguez-Fernández Luis Roberto , Ruiz-Constán Ana 
Published: April 2008

Abstract

The Neogene-Quaternary Almería-Níjar basin includes the Carboneras Fault, which constitutes a major left-lateral feature of the Betic Cordilleras. New gravity data help to determine the geometry of the sedimentary infill. The region underwent NE-SW extension during the Tortonian and local NW-SE compression during the first stages of Sierra Alhamilla uplift. During the Messinian, the sinistral strike-slip motion along the Carboneras Fault Zone, the dextral strike-slip motion along NW-SE-oriented faults, and the development of large folds such as the Sierra Alhamilla antiform, suggest clockwise rotation (towards the north) of the maximum stress axis (σ
1
). During the Pliocene, a NNW-SSE-oriented compression also contributes to fold development. Finally, during the Quaternary, an ENE-WSW-directed extension controls the development of NW-SE-oriented normal oblique faults. The most recent local normal activity of the Carboneras Fault is related to this extension, whereas its behaviour as a left-lateral strike-slip fault may be a consequence of the accommodation of NW-SE normal fault displacements. Basic rock bodies, recognized by means of a detailed study of the magnetic anomalies, are related to the volcanic activity known to have occurred in the area in Late Miocene times.
The Upper Cretaceous in the Tagus Basin (Central Spain): sequential analysis based on oil-well data and outcrop correlation
Authors: Segura Manuel , Polo Teresa , García-Hidalgo José F. , Gil Javier , Carenas Beatriz , García Álvaro 
Published: April 2008

Abstract
The logs from six oil wells drilled between 1960 and 1980 in the Upper Cretaceous succession of the Tagus Basin were analysed and correlated with surface outcrops, to estimate sedimentary environments and to detect cyclicity in sedimentation. Log interpretation has been carefully checked with outcrop data, because high peaks in gamma-ray logs, usually considered to represent open marine facies, may correspond either to open marine or to muddy coastal deposits. The former correspond to the maximum flooding surfaces of depositional sequences, whereas the latter correspond to sequence boundaries. Three second-order depositional megasequences have been recognized (MS-2, MS-3 and MS-4). The basal megasequence onlaps older rocks, grading upwards from continental to marine deposits. The megasequence MS-3 shows a basal marly transgressive interval and a thick carbonate pile at the top, grading to the SE to sabkha environments. The top megasequence is hardly recognized in surface outcrops, but in well logs it is a thick evaporite — claystone unit of mainly sabkha environments that grade westwards to coastal deposits. Sedimentation of megasequences MS-3 and MS-4 extended farther west than previously considered, covering areas considered as part of the exposed Hesperian Massif. These were areas of marine and coastal sedimentation where organic matter accumulation could be potentially high, and can be considered potential areas for oil or gas exploration.
Palaeogeography of the Upper Cretaceous-Eocene carbonate turbidites of the Northern Apennines from provenance studies
Authors: Argnani Andrea , Fontana Daniela , Stefani Cristina , Zuffa Gian G. 
Published: April 2008

Abstract
The Upper Cretaceous Helminthoid Flysch (HF) of the Northern Apennines consists of thick and regionally widespread deep-water carbonate turbidite successions, deposited during the initial stages of Alpine collision. The HF spans the time from Turonian to Early Eocene and is mainly composed of intrabasinal carbonate ooze mixed with clay; siliciclastic terrigenous beds are also present, but they are a volumetrically minor component of the successions. Petrographic and sedimentological signatures indicate that the HF was deposited in distinct basins located below the carbonate compensation depth. Bulk composition and heavy minerals of terrigenous beds indicate provenance from different crustal levels of the European and Adria plates. The petrographic and palaeobathymetric characteristics of these turbidites indicate the coexistence of an active-margin tectonic setting, a palaeogeographical position suitable for carbonate ooze production and storage, and limited supply of terrigenous detritus into the basin. Palaeotectonic reconstructions and stratigraphic data suggest that Adria represented a vast repository of penecon-temporaneous carbonate mud; the presumably intense seismic activity related to the pre-collisional Alpine orogeny promoted large-scale failures of shelf and/or slope biogenic muddy sediments, resulting in the deposition of a large volume of carbonate turbidites. Only occasionally, turbidity currents probably linked to exceptional fluvial floods generated pure terrigenous beds with different petrographic signatures for each HF succession.