Rocks metamorphosed under high-pressure (HP) and ultra high-pressure (UHP) conditions in subduction zones come back to the surface relatively soon after their burial and at rates comparable to plate boundary velocities. In the Mediterranean realm, their occurrence in several belts related to a single subduction event shows that the burial-exhumation cycle is a recurrent transient process. Using...

S U M M A R Y Although parts of the lithosphere may be expected to behave elastically over certain timescales, this effect is commonly ignored in models of large-scale mantle dynamics. Recently it has been demonstrated that elasticity, and in particular viscoelasticity, may have a significant effect on the buckling instability and on the creation of lithospheric-scale shearzones. It is, however...

Introduction: Mafic igneous rocks serve as probes of the interiors of their parent bodies – the compositions of the magmas contain an imprint of the source region composition and mineralogy, the melting and crystallization processes, and mixing and assimilation. Although complicated by their multifarious history, it is possible to constrain the petrologic evolution of an igneous province throug...

Abstract The growth of continental crust through melt extraction from the mantle is a critical component chemical evolution Earth and development plate tectonics. However, mechanisms involved remain debated. Here, we conduct petrological geochemical analyses on large (up to 5000 km 2 ) granitoid body in Arabian-Nubian shield near El-Shadli, Egypt. We identify these rocks as largest known plagio...

Geometric spreading of Pn and Sn waves in a spherical Earth model is different than that of classical headwaves and is frequency dependent. The behavior cannot be fully represented by a frequency-independent power-law model, as is commonly assumed. The lack of an accurate representation of Pn and Sn geometric spreading in a spherical Earth model impedes our ability to characterize Earth propert...

In order to reveal the influence of ammonium salts on rare earth leaching process weathered crust elution-deposited ores, acetate, chloride, and sulfate were used as agents. The effects agent efficiency expansion, dissolution, transformation behavior clay minerals in studied. results showed that followed acetate > chloride sulfate, with values 90.60%, 85.96%, 84.12%, respectively. swelling r...

The Accessible Silicate Earth (ASE) has a higher Nd/Nd ratio than most chondrites. Thus, if the Earth is assumed to have formed from these chondrites, a complement low-Nd/Nd reservoir is needed. Such a lowNd/Nd reservoir is believed to have been derived from a melt in the early Earth and is called the Early Enriched Reservoir (EER). Although the major element composition of the EER is crucial f...

Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of ...

A review of continental growth models leaves open the possibilities that Earth during the Hadean Eon (∼4.5–4.0 Ga) was characterized by massive early crust or essentially none at all. Without support from the rock record, our understanding of pre-Archean continental crust must largely come from investigating Hadean detrital zircons. We know that these ancient zircons yield relatively low crysta...