scholarly journals PyBacktrack 1.0: A Tool for Reconstructing Paleobathymetry on Oceanic and Continental Crust

2018 ◽  
Vol 19 (6) ◽  
pp. 1898-1909 ◽  
Author(s):  
R. D. Müller ◽  
J. Cannon ◽  
S. Williams ◽  
A. Dutkiewicz
Keyword(s):  
Continental Crust ◽  
Oceanic And Continental Crust

French and Belgian Uplands

2005 ◽  
Author(s):  
Bernard Etlicher
Keyword(s):  
Continental Crust ◽  
Rift Valley ◽  
Sedimentary Basins ◽  
Shear Zones ◽  
Metamorphic Complex ◽  
French Massif Central ◽  
Massif Central ◽  
Montagne Noire ◽  
Oceanic And Continental Crust ◽  
Moderate Elevation

The French Uplands were built by the Hercynian orogenesis. The French Massif Central occupies one-sixth of the area of France and shows various landscapes. It is the highest upland, 1,886 m at the Sancy, and the most complex. The Vosges massif is a small massif, quite similar to the Schwarzwald in Germany, from which it is separated by the Rhine Rift Valley. Near the border of France, Belgium, and Germany, the Ardennes upland has a very moderate elevation. The largest part of this massif lies in Belgium. Though Brittany is partly made up of igneous and metamorphic rocks, it cannot be truly considered as an upland; in the main parts of Brittany, altitudes are lower than in the Parisian basin. Similarities of the landscape in the French and Belgian Uplands derive from two major events: the Oligocene rifting event and the Alpine tectonic phase. The Vosges and the Massif Central are located on the collision zone of the Variscan orogen. In contrast, the Ardennes is in a marginal position where primary sediments cover the igneous basement. Four main periods are defined during the Hercynian orogenesis (Bard et al. 1980; Autran 1984; Ledru et al. 1989; Faure et al. 1997). The early Variscan period corresponds to a subduction of oceanic and continental crust and a highpressure metamorphism (450–400 Ma) The medio- Variscan period corresponds to a continent–continent collision of the chain (400–340 Ma). Metamorphism under middle pressure conditions took place and controlled the formation of many granite plutons: e.g. red granites (granites rouges), porphyroid granite, and granodiorite incorporated in a metamorphic complex basement of various rocks. The neo-Variscan period (340–320 Ma) is characterized by a strong folding event: transcurrent shear zones affected the units of the previous periods and the first sedimentary basins appeared. At the end of this period, late-Variscan (330–280 Ma), autochthonous granites crystallized under low-pressure conditions related to a post-collision thinning of the crust. Velay and Montagne Noire granites are the main massifs generated by this event. Sediment deposition in tectonic basins during Carboniferous and Permian times occurred in the Massif Central and the Vosges: facies are sandstone (Vosges), shale, coal, and sandstone in several Stephanian basins of the Massif Central, with red shale and clay ‘Rougier’ in the south-western part of the Massif Central.

Zircon Hf-O isotope evidence for recycled oceanic and continental crust in the sources of alkaline rocks

Geology ◽  
2017 ◽  
Vol 45 (5) ◽  
pp. 407-410 ◽  
Author(s):  
Yu-Sheng Zhu ◽  
Jin-Hui Yang ◽  
Jin-Feng Sun ◽  
Hao Wang
Keyword(s):  
Continental Crust ◽  
Alkaline Rocks ◽  
Isotope Evidence ◽  
O Isotope ◽  
Oceanic And Continental Crust

scholarly journals Andesitic Magmatism on a Differentiated Asteroid

2021 ◽  
Author(s):  
Robert Nicklas ◽  
James Day ◽  
Kathryn Gardner-Vandy ◽  
Arya Udry
Keyword(s):  
Partial Melting ◽  
Continental Crust ◽  
Parent Body ◽  
Volatile Components ◽  
Highly Siderophile Elements ◽  
The Past ◽  
Metal Silicate ◽  
Oceanic And Continental Crust ◽  
Siderophile Elements ◽  
Melt Composition

Abstract The Earth differs from other terrestrial planets in having a substantial silica-rich continental crust with a bulk andesitic composition1. The compositional dichotomy between oceanic and continental crust is likely related to water-rich subduction processes2. Over the past decade, the discovery of meteorites with andesitic bulk compositions have demonstrated that continental-crust like compositions can be attained through partial melting of chondritic protoliths3,4,5. Here we show that a newly identified achondrite meteorite, Erg Chech (EC) 002, is a high-Mg andesite but that, unlike previous andesitic achondrites has strongly fractionated and low abundances of the highly siderophile elements (HSE), reminiscent of Earth’s upper continental crust6. The major and HSE composition of EC 002 can be explained if its asteroid parent body underwent metal-silicate equilibrium prior to silicate partial melting without losing significant volatile components. The chemistry of pyroxene grains in EC 002 suggests it approximates a parental melt composition, which cannot be produced by partial melting of pre-existing basaltic lithologies, but more likely requires a metal-free chondritic source. Erg Chech 002 likely formed by ~ 15% melting of the mantle of an alkali-undepleted differentiated asteroid. The discovery of EC 002 shows that extensive silicate differentiation after metal-silicate equilibration was already occurring in the first two million years of solar system history7, and that andesitic crustal compositions do not always require water-rich subduction processes to be produced.

scholarly journals Evolution of the oceanic and continental crust during Neo-Proterozoic and Phanerozoic

2014 ◽  
Vol 25 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Peter Varga ◽  
Friedhelm W. Krumm ◽  
Erik W. Grafarend ◽  
Nico Sneeuw ◽  
Anatoly A. Schreider ◽  
...  
Keyword(s):  
Continental Crust ◽  
Oceanic And Continental Crust

Abilities of explosion seismology in oceanic and continental crust and mantle studies

1968 ◽  
Vol 5 (4) ◽  
pp. 1091-1100 ◽  
Author(s):  
I. P. Kosminskaya ◽  
S. M. Zverev
Keyword(s):  
Continental Crust ◽  
Resolving Power ◽  
Deep Seismic Sounding ◽  
Physical Parameters ◽  
Seismic Sounding ◽  
Seismic Records ◽  
Oceanic And Continental Crust

Some physical parameters of explosion seismology are discussed, such as: the levels of useful explosion signals and microseisms and their spectra; resolving power of the Deep Seismic Sounding (DSS) method; models of the crust and the possibility of increasing the information which could be extracted from seismic records.

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