Early Miocene continental subduction and rapid exhumation in the western Mediterranean

Geology ◽  
2006 ◽  
Vol 34 (11) ◽  
pp. 981 ◽  
Author(s):  
John P. Platt ◽  
Robert Anczkiewicz ◽  
Juan-Ignacio Soto ◽  
Simon P. Kelley ◽  
Matthew Thirlwall
Keyword(s):  
Western Mediterranean ◽  
Early Miocene ◽  
Continental Subduction

The Numidian Sand Event in the Burdigalian Foreland Basin System of the Rif (Morocco) in a source-to-sink perspective

2021 ◽  
Author(s):  
Anas Abbassi ◽  
Paola Cipollari ◽  
Maria Giuditta Fellin ◽  
Mohamed Najib Zaghloul ◽  
Marcel Guillong ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Large Population ◽  
Foreland Basin ◽  
Source Area ◽  
Western Mediterranean ◽  
Early Miocene ◽  
Calcareous Nannofossils ◽  
External Zone ◽  
Field Evidence ◽  
Basin System

<p>During the Tertiary evolution of the Western Mediterranean subduction system, the orogenic accretion at the Maghrebian margin let the stacking of three main tectonic zones of the Rif fold-and-thrust belt: 1) the Internal Zone; 2) the “Maghrebian Flysch” Nappes; and 3) the  External Zone. In this context, a migrating foreland basin system developed between the Maghrebian orogenic belt and the adjacent African Craton. </p><p>A comprehensive reconstruction of the foreland basin system of the Rif Chain for each phase of its accretional history is still missing. In this work, by integrating field observations with quantitative biostratigraphic data from calcareous nannofossils assemblages, sandstone composition, and detrital zircon U-Pb geochronology from selected stratigraphic successions, we reconstruct the foreland basin system that in the early Miocene developed in front of the growing Rif orogen. The analyzed successions are representative of (1) the “Beliounis Facies”, made of quartz-arenites and litharenites (Numidian-like “mixed succession”), from the Predorsalian Unit; (2) the “Mérinides Facies”, made of a Numidian-like “mixed succession”, from the “Maghrebian Flysch Basin”; and (3) the classical “Numidian Facies”, exclusively made of quartzarenites, from the Intrarifian Tanger Unit.</p><p>The petrographic analyses and the detrital zircon U-Pb ages show the provenance of the quartzarenites of the “Numidian Facies” from the African Craton, whereas the sublitharenites and feldspathic litharenites, of both the “Mérinides Facies” and “Beliounis Facies”, show provenance from a cratonic area and the growing and unroofing Rif Chain, respectively. </p><p>The Alpine signature of the detrital grains sedimented into the foredeep deposits of the early Miocene orogenic system of the Rif Chain is from the feldspathic litharenites of both the Mérinides Facies and the Beni Ider Flysch. Both show Mesozoic and Cenozoic U-Pb zircon populations, with a large population of zircons centered at ca. 32 Ma. The U and Th concentration, the Th/U ratio, and the REE pattern of this population of zircons suggest a possible source area from Oligocene doleritic rock intrusions, similar to the magmatic dyke swarms (diorite) cropping out in the Malaga region ( SE Spain).</p><p>The biostratigraphic analyses pinpoint the same age for the arrival of the quartz grains in the Numidian, Mérinides, and Beliounis deposits, indicating about 1 Myr for their sedimentation (ca. 20-19 Ma, early Burdigalian). Together with field evidence, the biostratigraphic results point to an autochthonous deposition of the Numidian Sandstones on top of the Tanger Unit, allowing to delineate the early Burdigalian foreland basin system of the Rif Chain. The foreland depozone involved the Tanger Unit and received the “Numidian Facies” deposits ; the foredeep depozone hosted about 2000 m of the “Mérinides Facies” and the Beni Ider Flysch, and developed on the so-called “Flysch Basin Domain”; and, finally, the wedge-top depozone, characterized by the “Beliounis Facies”, developed on top of the Predorsalian Unit.</p><p>The Numidian Sandstones and the Numidian-like deposits analyzed in Morocco show the same age of similar deposits from Algeria, Tunisia, and Sicily, suggesting a comparable early Burdigalian tectono-sedimentary evolution along the southern branch of the Western Mediterranean subduction-related orogen.</p>

Permo-Carboniferous and early Miocene geological evolution of the internal zones of the Maghrebides – New insights on the western Mediterranean evolution

2016 ◽  
Vol 96 ◽  
pp. 146-173 ◽  
Author(s):  
Laure Fernandez ◽  
Delphine Bosch ◽  
Olivier Bruguier ◽  
Dalila Hammor ◽  
Renaud Caby ◽  
...  
Keyword(s):  
Western Mediterranean ◽  
Early Miocene ◽  
Geological Evolution

A new fossil species of Euleptes from the early Miocene of Montaigu, France (Reptilia, Gekkonidae)

2001 ◽  
Vol 22 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Johannes Müller
Keyword(s):  
Mediterranean Region ◽  
Western Mediterranean ◽  
Early Miocene ◽  
Fossil Species ◽  
The Third ◽  
Modern Form

AbstractA new fossil leaf-toed gecko, Euleptes gallica sp. nov., is described from the early Miocene locality Montaigu, France. The species is the third record of leaf-toed geckos in the early Miocene of Europe. A palaeobiogeographical interpretation suggests that the modern form is a relic endemite of the western Mediterranean region which survived the extinction of its congeneric relatives by being isolated on the Corso-Sardinian microplate, which left its former position at the beginning of the Miocene.

Chronostratigraphy and paleomagnetism of Oligo-Miocene deposits of Corsica (France) : geodynamic implications for the liguro-provençal basin spreading

2003 ◽  
Vol 174 (4) ◽  
pp. 357-371 ◽  
Author(s):  
Jean Ferrandini ◽  
Jérôme Gattacceca ◽  
Michelle Ferrandini ◽  
Alan Deino ◽  
Marie-Christine Janin
Keyword(s):  
Short Interval ◽  
Western Mediterranean ◽  
Early Miocene ◽  
Paleomagnetic Data ◽  
Tyrrhenian Sea ◽  
Anticlockwise Rotation ◽  
Paleomagnetic Study ◽  
Sedimentary Succession ◽  
Two Stages ◽  
Ligurian Basin

Abstract In a context of convergence between Africa and Europe, the western Mediterranean domain is characterized by the opening of the Liguro-Provençal ocean in the early Miocene and of the Tyrrhenian Sea since the middle Miocene. These openings are preceded by an Oligocene rifting episod. New biostratigraphic, geochronologic and paleomagnetic data allow to propose an integrated stratigraphy sketch for the Oligo-Miocene period in Corsica. The continental syn-rift deposits, in the region of Ajaccio, have been dated as late Chattian from the presence of a mammal, Pomelomeryx boulangeri. Their paleomagnetic study indicates an anticlockwise rotation of 44 ±4° with regard to the stable Europe. The early Miocene succession was deposited on a contrasted topography inherited from the Oligocene glyptogenesis period. The lowermost Miocene deposits are represented by 4 pyroclastic flow deposits in southern Corsica. New 40Ar-39Ar datings on plagioclase concentrates give ages between 21.3 and 20.6 Ma (late Aquitanian). Paleomagnetic directions indicates that the rotation of Corsica had probably begun at this time. The Miocene marine sediments of the Bonifacio basin are divided in two formations. At the base, the Cala di Labra formation, that comprises 3 reef formations in coastal onlap (R1, R2, R3), is attributable to the Globigerinoides trilobus zone. In the environment of R1, miogypsin population includes mainly Miogypsina intermedia with a few M. globulina and M. cushmani. The absence of the less evolved forms (10 < V < 35) let us suppose that at least the lower Burdigalian is absent at Bonifacio because the region was emerged. R2 reef has a similar population (42 < V < 70), which suggests a rather short interval of time between the two stages of reef construction. On the other hand the R3 population contains only evolved forms (M. mediterranea) suggesting a late Burdigalian age. The end of the sedimentary succession (Bonifacio formation) is essentially represented by a pile of hydraulic dunes. The absence of Orbulina shows that this upper unit is older than late Langhian (biozone N9). Miocene sediments from Saint-Florent are divided into 3 marine formations bracketed by two continental ones. At the base, the continental formation of Fium’Albinu (equivalent to the Cala di Labra formation) is surmounted by the Torra formation attributed to Late Burdigalian based on the presence of G. trilobus and G. bisphericus. The Sant’Angelo formation (equivalent to the Bonifacio formation) developed from latest Burdigalian to late Langhian. The Farinole formation represents early Serravallian (base of the Globoquadrina altispira altispira zone). Despite the large number of studied sites in this study and others, the only reliable Oligo-Miocene paleomagnetic results in Corsica are the following ones : – the Vazzio formation indicates a rotation of 44 ± 4° after the late Oligocene, – the southern volcanic flows show that the rotation was in progress around 20.7 Ma (late Aquitanian), – the Fium’Albinu formation indicates a rotation of 30 ± 12° after early Burdigalian, – site B from Vigliotti and Kent [1990] gives a rotation of about 11 ± 5° after early Langhian. Our paleomagnetic data, together with the existing ones, associated to the biostratigraphic and geochronologic ages show that the opening of the Ligurian basin coincides with an anticlockwise rotation of 45° of Corsica, which begins between 23 and 21 Ma and ends around 15 Ma. This is in agreement with the idea of Sardinia and Corsica rotating as a single almost rigid block during Miocene times.

Early Miocene tephra in the Apennine pelagic sequence: An inferred Sardinian provenance and implications for western Mediterranean tectonics

Tectonics ◽  
1994 ◽  
Vol 13 (5) ◽  
pp. 1120-1134 ◽  
Author(s):  
A. Montanari ◽  
S. Carey ◽  
R. Coccioni ◽  
A. Deino
Keyword(s):  
Western Mediterranean ◽  
Early Miocene

Late Oligocene–early Miocene transformation of postcollisional magmatism in Tibet

Geology ◽  
2019 ◽  
Vol 47 (8) ◽  
pp. 776-780 ◽  
Author(s):  
Zhengfu Guo ◽  
Marjorie Wilson
Keyword(s):  
Evolutionary Model ◽  
Climate Forcing ◽  
Early Miocene ◽  
The Tibetan Plateau ◽  
Carbonate Sediments ◽  
Continental Lithosphere ◽  
Continental Subduction ◽  
Magmatic Rocks ◽  
Modern Analogue ◽  
Comprehensive Compilation

Abstract Uplift of the Tibetan Plateau is thought to be one of the most important orogenic and climate forcing events of the Cenozoic Era, associated with geodynamic changes related to India-Asia collision and subsequent continental lithosphere subduction. However, the fate and scale of the subducted continental lithosphere segments remain highly controversial. Using a comprehensive compilation of the spatiotemporal distribution of postcollisional magmatic rocks across Tibet, together with new geochemical and Sr-Nd-Pb isotopic data and modeling simulations, we propose a holistic, two-stage evolutionary model to explain the link between genesis of the magmas and continental subduction. The magmatism prior to 25 Ma resulted from continuous upwelling of a carbonate-rich upper-mantle plume induced by northward underthrusting of Indian oceanic and continental lithosphere with its cover of Tethyan platform carbonate sediments, whereas magmatism after 25 Ma was related to opposing north-directed and south-directed continental subduction. Our model indicates a transformation in the distribution and nature of the magmatism in Tibet at ca. 25 Ma, which reflects a significant change in the Himalayan-Tibetan orogen and associated mantle dynamic processes in the early Miocene. Understanding this transformation could have important implications for the utility of the Himalayan-Tibetan system as a modern analogue for ancient orogens.

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