Two main Sedimentary cycles and two different rift system during the Pangea break-up in the Alps

2015 ◽  
Vol 37 ◽  
pp. 54-56
Author(s):  
Leonsevero Passeri
Keyword(s):  
Rift System ◽  
Sedimentary Cycles ◽  
The Alps ◽  
Break Up

About this title - Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up

10.1144/m55 ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. NP-NP
Keyword(s):  
Lava Lake ◽  
Rift System ◽  
West Antarctic ◽  
Continental Arc ◽  
Lithospheric Extension ◽  
Break Up ◽  
Felsic Volcanic ◽  
Mafic Volcanism ◽  
Back Arc ◽  
West Antarctic Rift System

This memoir is the first to review all of Antarctica's volcanism between 200 million years ago and the Present. The region is still volcanically active. The volume is an amalgamation of in-depth syntheses, which are presented within distinctly different tectonic settings. Each is described in terms of (1) the volcanology and eruptive palaeoenvironments; (2) petrology and origin of magma; and (3) active volcanism, including tephrochronology. Important volcanic episodes include: astonishingly voluminous mafic and felsic volcanic deposits associated with the Jurassic break-up of Gondwana; the construction and progressive demise of a major Jurassic to Present continental arc, including back-arc alkaline basalts and volcanism in a young ensialic marginal basin; Miocene to Pleistocene mafic volcanism associated with post-subduction slab-window formation; numerous Neogene alkaline volcanoes, including the massive Erebus volcano and its persistent phonolitic lava lake, that are widely distributed within and adjacent to one of the world's major zones of lithospheric extension (the West Antarctic Rift System); and very young ultrapotassic volcanism erupted subglacially and forming a world-wide type example (Gaussberg).

Chapter 1.2 Antarctic volcanism: volcanology and palaeoenvironmental overview

2021 ◽  
pp. M55-2020-1 ◽  
Author(s):  
John L. Smellie
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Critical Parameters ◽  
Rift System ◽  
Mass Extinctions ◽  
Volcanic Arc ◽  
Principal Characteristics ◽  
West Antarctic ◽  
Alkaline Volcanism ◽  
Break Up

AbstractSince Jurassic time (c. 200 Ma), Antarctica has had a greater diversity of volcanism than other southern continents. It includes: (1) voluminous mafic and felsic volcanism associated with the break-up of Gondwana; (2) a long-lived continental margin volcanic arc, including back-arc alkaline volcanism linked to slab rollback; (3) small-volume mafic alkaline volcanism associated with slab-window formation; and (4) one of Earth's major continental rift zones, the West Antarctic Rift System (WARS), with its numerous large alkaline central volcanoes. Several of Antarctica's volcanoes are still active. This chapter is a review of the major volcanic episodes and their principal characteristics, in their tectonic, volcanological and palaeoenvironmental contexts. Jurassic Gondwana break-up was associated with large-scale volcanism that caused global environmental changes and associated mass extinctions. The volcanic arc was a major extensional arc characterized by alternating volcanic flare-ups and lulls. The Neogene rift-related alkaline volcanism is dominated by effusive glaciovolcanic eruptions, overwhelmingly as both pāhoehoe- and ‘a‘ā-sourced lava-fed deltas. The rift is conspicuously poor in pyroclastic rocks due to the advection and removal of tephra erupted during glacial intervals. Volcanological investigations of the Neogene volcanism have also significantly increased our knowledge of the critical parameters and development of the Antarctic Ice Sheet.

scholarly journals The role of inheritance in forming rifts and rifted margins and building collisional orogens: a Biscay-Pyrenean perspective

2021 ◽  
Author(s):  
Gianreto Manatschal ◽  
Pauline Chenin ◽  
Rodolphe Lescoutre ◽  
Jordi Miró ◽  
Patricia Cadenas ◽  
...  
Keyword(s):  
Numerical Models ◽  
Rift System ◽  
Rifted Margins ◽  
New Concepts ◽  
The Alps ◽  
Orogenic Cycle ◽  
Work Done ◽  
Collisional Orogens ◽  
Rifted Margin

The aim of this paper is to provide a conceptual framework that integrates the role of inheritance in the study of rifts, rifted margins and collisional orogens based on the work done in the OROGEN project, which focuses on the Biscay-Pyrenean system. The Biscay-Pyrenean rift system resulted from a complex multistage rift evolution that developed over a complex lithosphere pre-structured by the Variscan orogenic cycle. There is a general agreement that the Pyrenean-Cantabrian orogen resulted from the reactivation of an increasingly mature rift system along-strike, ranging from a mature rifted margin in the west to an immature and segmented hyperextended rift in the east. However, different models have been proposed to explain the preceding syn-rift evolution and its influence on the subsequent reactivation. Results from the OROGEN project show a sequential reactivation of rift inherited decoupling horizons and identify the specific role of exhumed mantle, hyperextended and necking domains during reactivation. They also highlight the contrasting fate of segment centres vs. segment boundaries during convergence, explaining the non-cylindricity of internal parts of collisional orogens. Results from the OROGEN project also suggest that the role of inheritance is more important during the initial stages of subduction and collision, which may explain the complexity of internal parts of orogenic systems. In contrast, once tectonic systems get more mature, orogenic evolution becomes mostly controlled by first-order physical processes as described in the Coulomb Wedge theory for instance. This may account for the simpler and more continuous architecture of external parts of collisional orogens. It may also explain why most numerical models can reproduce mature orogenic and rift architectures with better accuracy compared to the initial stages of such systems. Thus, while inheritance may not explain steady-state processes, it is a prerequisite for comprehending the initial stages of tectonic systems. The new concepts developed from the OROGEN research are now ready to be tested at other orogenic systems that result from the reactivation of rifted margins, such as the Alps, the Colombian cordilleras and the Caribbean, Taiwan, Oman, Zagros or Timor.

scholarly journals Plume Versus Slab-Pull: Example from the Arabian Plate

2021 ◽  
Vol 9 ◽  
Author(s):  
Thamer Z. Aldaajani ◽  
Khalid A. Almalki ◽  
Peter G. Betts
Keyword(s):  
Mantle Plume ◽  
Plate Tectonics ◽  
Plate Motion ◽  
Arabian Plate ◽  
Rift System ◽  
Far Field ◽  
Buoyant Plumes ◽  
Field Plate ◽  
Break Up ◽  
Complex Structural

Mantle convection and the interaction of buoyant plumes with the lithosphere have been a significant influence on plate tectonics. Plume-lithosphere interactions have been regarded as a major driver of continental rifting, and have been linked to triple junction development and major supercontinent break-up events. There are also many extensional tectonic settings that lack evidence for a mantle plume and associated magmatism, indicating far-field plate stresses also drive plate fragmentation. The Arabian Plate is a spectacular active example where both a mantle plume and far-field plate stresses interact to drive continental break-up. Despite more than 80 years of geological research, there remains significant conjecture concerning the geodynamic processes responsible for the plate motion and the nature or onset of extension/deformation of the Arabian Plate. Complex structural patterns within the Arabian Plate have been interpreted in the context of tectonic plate movements and reorganization related to the subduction of the Tethys Oceanic plate, collision between Arabian and Eurasian plates, and the superposition of Afar plume. These interactions have accordingly resulted in different explanations or understanding of the geodynamic of the Afro-Arabian rift system. We assess the relative influence of plume vs. far field influences by reviewing the current views on the concept and models of these forces and highlighting their significance and implications on Arabia. Our synthesis shows that most of the geodynamical models proposed so far are not applicable to the entire Arabian Plate and its surrounding boundaries.

The transition from Variscan collision to continental break-up in the Alps: insights from the comparison between natural data and numerical model predictions

2014 ◽  
Vol 405 (1) ◽  
pp. 363-400 ◽  
Author(s):  
Maria Iole Spalla ◽  
Davide Zanoni ◽  
Anna Maria Marotta ◽  
Gisella Rebay ◽  
Manuel Roda ◽  
...  
Keyword(s):  
Numerical Model ◽  
Model Predictions ◽  
Natural Data ◽  
The Alps ◽  
Break Up

scholarly journals The Limagne Basin: a journey through modern and fossil microbial deposits

2021 ◽  
Author(s):  
Emmanuelle Vennin ◽  
Anthony Bouton ◽  
Adeline Roche ◽  
Emmanuelle ◽  
Gérard ◽  
...  
Keyword(s):  
Microbial Mats ◽  
Temporal Distribution ◽  
Thermal Spring ◽  
Rift System ◽  
Important Place ◽  
Massif Central ◽  
History Of ◽  
The Alps ◽  
Spatio Temporal ◽  
Controlling Processes

The Limagne Basin (Massif Central, France) originated during a major, European-scale, extensive event (European Cenozoic Rift System), which led to the formation of several rift systems in the foreland of the Alps between the Upper Eocene and Pliocene. A fluvio-lacustrine system emplaced in the basin and resulted in a mixed carbonate-siliciclastic sedimentation in which microbial and metazoan buildups occupy an important place. However, microbial deposits are not exclusive to the Cenozoic history of the Limagne Basin; nowadays, in the basin, they still form in association with thermal spring systems. A fieldtrip was carried out in the Limagne Basin as part of the Microbialites: formation, evolution and diagenesis (M-Fed) meeting (October 2019). The objective of this excursion was to assess the diversity of modern and fossil (Chattian to Aquitanian) microbial sediments and structures in three prime locations (the Jussat and Chadrat outcrops and the Grand Gandaillat quarry). A detailed description of the morphologies and fabrics of the buildups and their associated biotic components can be used to discuss the spatio-temporal distribution pattern. Different margin models are proposed based on the changes in the distribution, morphology and size of the microbial and metazoan-rich deposits through time. The Jussat outcrop offers novel perspectives to unravel the evolution of the lacustrine/palustrine cycles over time and to establish a long-term paleoenvironmental history of the western margin of the basin during the Aquitanian. These cycles are composed of (i) lacustrine sedimentation comprising microbial and metazoan buildups and organic matter-rich marls reflecting a period of high accommodation, and (ii) palustrine deposits made of mudstones and clayey paleosoils, indicative of a period of low accommodation. It is suggested that climatic, tectonic, volcanic and local parameters (physiography, substrate) control the deposition of the buildups in each of the different cycles. In addition, the modern microbial mats of the Sainte-Marguerite and La Poix outcrops offer an opportunity to approach the controlling processes at the origin of the mineralization involved in the formation of the microbialites and their preservation in the fossil record.

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