The Paikon massif revisited, comments on the late Cretaceous - Paleogene geodynamics of the Axios-Vardar zone. How many Jurassic ophiolitic basins? (Hellenides, Macedonia, Greece)

In the Axios-Vardar zone, the Paikon massif has been revisited. To the west, it is composed of a pile-up of SW dipping slices. These have been thrust toward the NNE while the Almopias zone was folding with a SSW vergence. Subsequently thrusting with a SW vergence occurred on the eastern flank of the Paikon massif and in the Almopias zone. These tectonic events took place during the Paleocene - early Eocene and during the upper Eocene - lower Oligocene respectively. During the late Cretaceous, the Almopias zone was a trough whose floor was a late Jurassic ophiolitic sheet. It was located between the Paikon carbonate platform and the Pelagonian platform. This analysis leads to the conclusion that the ophiolites were already located in the Almopias zone before the late Cretaceous and even before the upper Jurassic-lower Cretaceous. It is concluded that during the Jurassic the Almopias zone was an oceanic crust basin, the Paikon zone an island arc and the Peonias zone a back-arc basin. This analysis is a first step which is necessary to precise the geodynamic significance of the Axios- Vardar zone as a whole during the Triassic - Jurassic taking into account the stratigraphie, paleogeographic and structural data and the location in space and time of the magmatic and metamorphic belts

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Paleogeographie, orogenese, metamorphisme et magmatisme des zones internes des Hellenides en Macedoine (Grece); vue d'ensemble

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.s7-viii.7.1020 ◽

1966 ◽

Vol S7-VIII (7) ◽

pp. 1020-1049 ◽

Cited By ~ 12

Author(s):

Jacques Mercier

Keyword(s):

Early Cretaceous ◽

Late Cretaceous ◽

Middle Eocene ◽

Upper Jurassic ◽

Upper Eocene ◽

Vertical Movements ◽

Lower Oligocene ◽

Upper Paleozoic ◽

Igneous Activity ◽

Two Phases

Abstract Since the end of major Hercynian disturbances in the upper Paleozoic, the inner Hellenide zones, including the Peonia and Almopia troughs and the Paikon and Pelagonian ridges, have been affected by several periods of complex orogenic activity among which were four phases of tangential movements: Portlandian or terminal early Cretaceous, terminal Cretaceous to lower-middle Eocene, latest Priabonian, and post-lower Oligocene. Vertical movements took place before the last tangential phases, during Kimmeridgian-Portlandian and Turonian-Campanian time. Since the Hercynian and pre-Hercynian periods of metamorphism the inner Hellenides have been affected by dynamic metamorphism of post-Jurassic-pre-Albian-Aptian and post-Maestrichtian-pre-lower Oligocene age; post-middle-upper Eocene dynamic metamorphism had localized effects near structural contacts. Igneous activity associated with the metamorphism and orogenic movements was initially (Jurassic) ophiolitic; two phases of synorogenic (upper Jurassic-early Cretaceous and late Cretaceous to lower-middle Eocene) granitic activity followed and were in turn succeeded by three phases of postorogenic (Plio-Quaternary) andesitic, granitic-granodioritic, and basaltic activity.

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2D Numerical Simulation of Intraoceanic Subduction during the Upper Jurassic Closure of the Vardar Tethys

10.5194/egusphere-egu2020-5919 ◽

2020 ◽

Author(s):

Nikola Stanković ◽

Vesna Cvetkov ◽

Vladica Cvetković

Keyword(s):

Numerical Simulations ◽

Late Cretaceous ◽

Stokes Equations ◽

Numerical Models ◽

Upper Jurassic ◽

Staggered Grid ◽

Parameter Study ◽

Ongoing Research ◽

Magmatic Complex ◽

Vardar Zone

In this study we report interim results of our ongoing research that involves the application of numerical modeling for constraining the geodynamic conditions associated with the closure of the Vardar branch of the Tethys Ocean. The study is aimed at better understanding the ultimate fate of the Balkan ophiolites, namely at addressing the question whether these ophiolites represent relicts of an ocean that completely closed during Upper Jurassic/lowermost Cretaceous time (Vardar Tethys) or they also contain remnants of the ocean floor of a Late Cretaceous oceanic realm (Sava &#8211; Vardar) [Schmid et al., 2008].In our numerical models we try to simulate a single intraoceanic subduction that commences in the Lower/Mid Jurassic and ends in the Lower Cretaceous, transitioning into oceanic closure processes and subsequent collision between Adria and Eurasia plates. These convergent-collision events should have led to the formation of ophiolite-like igneous rocks of the so-called Sava - Vardar zone.A series of numerical simulations were performed with varying parameters. In the scope of our numerical simulations, the set of equations is solved: the continuity equation, the Navier-Stokes equations and the temperature equation. Marker in cell method was incorporated in solving this system with finite difference discretization of the equations on a staggered grid. To utilize this numerical method a thermo-mechanical code I2VIS [Gerya et al., 2000; Gerya & Yuen, 2003] was used for obtaining the final results.&#160;Our actual 2D thermo-mechanical models cover the crust and the upper portion of the mantle with varying starting widths of the Vardar Ocean in the Lower Jurassic. The ocean is modeled with two segments: the western subducting slab and the eastern overriding slab. Slabs with different ages and thicknesses were used and the convergence rate is varied. The intraoceanic subduction is assumed to have been initiated along the mid oceanic ridge. Two continents (i.e. Adria and Eurasia) with different thicknesses of the continental lithosphere and crust are also modeled adjacent to a single oceanic realm between them.The parameter study is in function of defining conditions under which the hypothesized scenario occurs. So far, we have succeeded in reproducing westward obduction onto the Adriatic margin, which is in accordance with the geological observations, i.e., with the top-west emplaced West Vardar ophiolites [see Schmid et al., 2008 for references]. However, our model is yet to produce sufficient amounts of back-arc extension along the Eurasian active margin and that is crucial for explaining the formation of the igneous provinces occurring within the Late Cretaceous Sava &#8211; Vardar zone and the Timok Magmatic Complex.

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From arc evolution to arc-continent collision: Late Cretaceous–middle Eocene geology of the Eastern Pontides, northeastern Turkey

Geological Society of America Bulletin ◽

10.1130/b31913.1 ◽

2019 ◽

Vol 131 (11-12) ◽

pp. 1889-1906 ◽

Cited By ~ 7

Author(s):

Özgür Kandemir ◽

Kenan Akbayram ◽

Mehmet Çobankaya ◽

Fatih Kanar ◽

Şükrü Pehlivan ◽

...

Keyword(s):

Late Cretaceous ◽

Middle Eocene ◽

Structural Data ◽

Massive Sulfide ◽

Arc Volcanism ◽

Eastern Pontides ◽

The North ◽

Fold And Thrust Belt ◽

Volcaniclastic Rocks ◽

Back Arc

Abstract The Eastern Pontide Arc, a major fossil submarine arc of the world, was formed by northward subduction of the northern Neo-Tethys lithosphere under the Eurasian margin. The arc’s volcano-sedimentary sequence and its cover contain abundant fossils. Our new systematical paleontological and structural data suggest the Late Cretaceous arc volcanism was initiated at early-middle Turonian and continued uninterruptedly until the end of the early Maastrichtian, in the northern part of the Eastern Pontides. We measured ∼5500-m-thick arc deposits, suggesting a deposition rate of ∼220 m Ma–1 in ∼25 m.y. We have also defined four different chemical volcanic episodes: (1) an early-middle Turonian–Santonian mafic-intermediate episode, (2) a Santonian acidic episode; when the main volcanic centers were formed as huge acidic domes-calderas comprising the volcanogenic massive sulfide ores, (3) a late Santonian–late Campanian mafic-intermediate episode, and (4) a late Campanian–early Maastrichtian acidic episode. The volcaniclastic rocks were deposited in a deepwater extensional basin until the late Campanian. Between late Campanian and early Maastrichtian, intra-arc extension resulted in opening of back-arc in the north, while the southern part of the arc remained active and uplifted. The back-arc basin was most probably connected to the Eastern Black Sea Basin. In the back-arc basin, early Maastrichtian volcano-sedimentary arc sequence was transitionally overlain by pelagic sediments until late Danian suggesting continuous deep-marine conditions. However, the subsidence of the uplifted-arc-region did not occur until late Maastrichtian. We have documented a Selandian–early Thanetian (57–60 Ma) regional hiatus defining the closure age of the İzmir-Ankara-Erzincan Ocean along the Eastern Pontides. Between late Thanetian and late Lutetian synorogenic turbidites and postcollisional volcanics were deposited. The Eastern Pontide fold-and-thrust belt started to form at early Eocene (ca. 55 Ma) and thrusting continued in the post-Lutetian times.

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Distributional patterns of ?Mawsoniidae (Sarcopterygii: Actinistia)

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201420130035 ◽

2014 ◽

Vol 86 (1) ◽

pp. 159-170 ◽

Cited By ~ 11

Author(s):

RAPHAEL MIGUEL ◽

VALÉRIA GALLO ◽

JUAN J. MORRONE

Keyword(s):

Southern Hemisphere ◽

Late Cretaceous ◽

Lower Cretaceous ◽

Late Jurassic ◽

Upper Jurassic ◽

Upper Triassic ◽

Late Triassic ◽

Tectonic Events ◽

Distributional Patterns ◽

Track Analysis

Mawsoniidae are a fossil family of actinistian fish popularly known as coelacanths, which are found in continental and marine paleoenvironments. The taxon is considered monophyletic, including five valid genera (Axelrodichthys, Chinlea, Diplurus, Mawsonia and Parnaibaia) and 11 genera with some taxonomical controversy (Alcoveria, Changxingia, Garnbergia, Heptanema, Indocoelacanthus, Libys, Lualabaea, Megalocoelacanthus, Moenkopia, Rhipis and Trachymetopon). The genera restricted to the Northern Hemisphere (Diplurus and Chinlea) possess the oldest records (Late Triassic), whereas those found in the Southern Hemisphere (Mawsonia, Axelrodichthys, and Parnaibaia) extend from Late Jurassic to Late Cretaceous, especially in Brazil and Africa. We identified distributional patterns of Mawsoniidae, applying the panbiogeographical method of track analysis, and obtained three generalized tracks (GTs): GT1 (Northeastern Newark) in strata of the Newark Group (Upper Triassic); GT2 (Midwestern Gondwana) in the Lualaba Formation (Upper Jurassic); and GT3 (Itapecuru-Alcântara-Santana) in the Itapecuru-Alcântara-Santana formations (Lower Cretaceous). The origin of Mawsoniidae can be dated to at least Late Triassic of Pangaea. The tectonic events related to the breakup of Pangaea and Gondwana and the evolution of the oceans are suggested as the vicariant events modeling the distribution of this taxon throughout the Mesozoic.

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Sur l'existence et l'age des deux phases regionales de metamorphisme alpin dans les zones internes des Hellenides en Macedoine centrale (Grece)

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.s7-viii.7.1014 ◽

1966 ◽

Vol S7-VIII (7) ◽

pp. 1014-1019 ◽

Cited By ~ 5

Author(s):

Jacques Mercier

Keyword(s):

Upper Jurassic ◽

Second Phase ◽

Upper Eocene ◽

Lower Oligocene ◽

Regional Phases ◽

Alpine Metamorphism

Abstract Two regional phases of alpine metamorphism developed contemporaneously in the inner zones of the Hellenides: the first phase was after the Triassic, probably in the upper Jurassic, and earlier than the upper Maestrichtian or even the Aptian-basal Albian; the second phase was after the upper Maestrichtian but before the lower Oligocene, probably in the Priabonian. In addition, a phase of dynamic metamorphism was manifest locally in the foreland of the Serbo-Macedonian massif, in volcanic and tuffaceous formations of middle-upper Eocene age; it was contemporaneous with the late Priabonian tectonic phase. Hercynian and pre-Hercynian cores are both represented in the inner Hellenides and were affected by the alpine metamorphism.

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Contribution a l'etude geologique des chainons compris entre l'Arc et la vallee de Lambesc a l'ouest d'Aix-en-Provence (Bouches-du-Rhone)

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.s7-viii.6.786 ◽

1966 ◽

Vol S7-VIII (6) ◽

pp. 786-792 ◽

Cited By ~ 1

Author(s):

Tristan Busser ◽

Albert Pachoud

Keyword(s):

Late Cretaceous ◽

Lower Cretaceous ◽

Upper Jurassic ◽

The Other ◽

Drill Core ◽

Upper Eocene ◽

Southern France ◽

Core Data ◽

East West

Abstract Surveys carried out west of Aix-en-Provence (southern France) supplemented by drill-core data from an exploratory boring for oil indicate that the upper Jurassic and lower Cretaceous are of greater thickness than heretofore thought. The facies are transitional between those of the coast and those of the Vocontian basin. This part of Provence, although formerly considered to have been affected only by superficial folds, is actually a large recumbent fold formed during two tectonic phases. One occurred during the late Cretaceous, developing an east-west-trending ridge; the other occurred during the upper Eocene, causing thrusting and overturning of the fold, whose crest had been removed by erosion.

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Intraoceanic subduction of the northwestern Neotethys and geodynamic interaction with Serbo-Macedonian foreland: Descending vs. overriding near-trench dynamic constraints (East Vardar Zone, Jastrebac Mts., Serbia)

Geoloski anali Balkanskog poluostrva ◽

10.2298/gabp1902065s ◽

2019 ◽

Vol 80 (2) ◽

pp. 65-85

Author(s):

Darko Spahic ◽

Tivadar Gaudenyi

Keyword(s):

Late Cretaceous ◽

Hanging Wall ◽

Lithospheric Structure ◽

Plate Boundaries ◽

Core Complex ◽

Lower Paleozoic ◽

Dynamic Constraints ◽

Vardar Zone ◽

Finite Configuration ◽

Back Arc

A composite paleogeographic and plate kinematic spatiotemporal reconstruction of the exhumed Neotethyan cross-lithospheric footwall amalgamation (Jastrebac dome) incorporates the two formerly underplating oceanic entities, West Vardar- and East Vardar Zone. These ophiolite-bearing agglomerations are unroofed within the accretionary Paleogene to Miocene core-complex, beneath the Serbo-Macedonian overriding plate. The exposed Neotethyan crustal amalgamation is comprised of: an (i) folded trench assemblage of uncertain Mesozoic? Paleogeographic affinity metamorphosed under a greenschist-grade (West- vs. East Vardar Zone or Neotethyan crust- vs. its back-arc system?) sandwiched beneath the overlying (ii) late Cretaceous - Paleogene (meta)turbidites. To make matters more intricate, at the closest proximity of the dome (Mali Jastrebac Mountain) there is a similar (iii) greenschist-facies amalgamation comprised of the Neoproterozoic - Lower Paleozoic ocean-floor assembly (Supragetic basement). The interpretations of this rather controversial cross-lithospheric structure include a reassessment of the obduction sequence, and are underpinned by the restoration of the near-trench microplate motions. The study addresses the (1) local finite configuration (Serbo-Macedonian hanging wall vs. Neo - tethyan intraoceanic arc) and the (2) spatiotemporal geometry of the principal (micro)plate boundaries (Serbo-Macedonian Unit vs. Apulia/Adria). Unlike the earlier proposal of the ophiolite obduction onto the Serbo-Macedonian Unit onto the Apulia/Adria hinterland (or external segment of the ?Dacia mega-terrane?), we here propose a west-vergent obduction of the East Vardar Zone ophiolites onto the descending Neotethyan lithosphere (West Vardar ophiolites) - a similar scenario to its continuation in Greece (Peonias subzone).

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The Succession of Upper Eocene- Upper Miocene Limestone Growth and Corresponding Tectonic Events in Luconia Shelf, Sarawak, Malaysia

Frontiers in Earth Science ◽

10.3389/feart.2021.588629 ◽

2021 ◽

Vol 9 ◽

Author(s):

Siti Nur Fathiyah Jamaludin ◽

Benjamin Sautter ◽

Manuel Pubellier ◽

Mirza Arshad Beg

Keyword(s):

South China Sea ◽

South China ◽

Upper Cretaceous ◽

Upper Eocene ◽

The South ◽

Lower Miocene ◽

Upper Miocene ◽

China Sea ◽

Tectonic Events ◽

Lower Oligocene

Using high quality regional seismic lines, we evidence major structures resulting from successive phases of tectonic events that affected the Luconia shelf from the Upper Cretaceous to Pliocene. Each tectonic event (Classified as Event 1–Event 3) is associated with different episodes of limestone growth in Luconia Province. The successive limestone growths are used as markers in constraining the timing and style of tectonic deformation. The poly-stage closure of the Proto South China Sea (PSCS) from the Upper Cretaceous to Lower Miocene led to the formation of compressional structures in its southern portion (South PSCS) providing elevated topography for the growth of the oldest limestone found in this area during the Upper Eocene to Lower Oligocene (Event 1). Based on contrasting seismic reflectors, morphology, and depositional patterns, the offshore Upper Eocene-Lower Oligocene limestone growth is correlated to the onshore Engkabang-Karap limestone. The southern part of Luconia was subjected to a continuous compression until the Lower Miocene at a time where the northern side of the Luconia Province was experiencing subsidence due to the rifting of the South China Sea (Event 2). The compression in the south generated elevated anticlines, triggering the growth of the Upper Oligocene to Lower Miocene limestone. By the end of the rifting event in the Lower Miocene, tectonic quiescence had enabled widespread carbonate growth in Luconia from the Middle to Upper Miocene. Regional compression due to the major uplift of Borneo hinterland (Event 3) triggered paramount clastic influx (gravity tectonics) to the offshore perturbating the limestone reef growth in Luconia. The impact of these interrelated shortening and stretching phases led to major crustal thickness variations and a prominent tilt of the Luconia platform that may highlight intricate feedbacks at the transition from compression to extension. While the southern side of the Luconia’s crustal fragment was anchored into Borneo hinterland, crustal extension in the northern region of Luconia led to a hyper-stretched crust characterized by low angle detachment faults and highly rotated blocks rising the mantle to its shallowest.

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