1-Introduction Damavand volcano was formed by explosive and non-explosive eruptions on the old eroded rock units (Mesozoic and older) of Central Alborz during the Quaternary period and formed two huge cone (Old and Young Damavand). Davidson et al. (2004) determined the time of Old-Damavand activity from 1800 to 800 thousand years ago by measuring Ar/Ar and U-Th/He methods. According to their ...

Assuming that the period 2.75–2.65 Ga corresponds to a single, but global, geodynamic event, we investigate—through numerical experiments—the mechanisms that could have led to the profound continental reworking that occurred at that time. Although the extent of the crisis at the Earth’s surface pledges in favour of the involvement of mantle plumes, our numerical experiments suggest that the the...

Earth’s dominant form of magmatism occurs at mid-ocean ridges (MORs), producing the igneous crust for two-thirds of the planet’s surface and conveying significant heat and material fluxes from the mantle to the world’s oceans. Mid-ocean-ridge basalt (MORB) magmas form from upwelling compositionally heterogeneous mantle1 by aggregation of near-fractional melts beneath spreading centres2. Multipl...

The initiation and evolution of seismic activity in intraplate regions are controlled by heterogeneous stress highly fractured rocks within the rock mass triggered fluid migration. In this study, we imaged electrical structure crust beneath Ganzi fault using a three-dimensional magnetotelluric inversion technique, which is host to an assemblage resistive conductive features extending into lower...

Arc magmas derived from mantle melting often have trace element and isotopic signatures that indicate crustal contributions. The origin extent of contributions are critical constraints for quantifying crust-mantle recycling at subduction zones; however, it is difficult to distinguish between inputs the downgoing oceanic slabs over-riding arc crust. Here we present a novel study using stable pot...

The formation and exhumation of high and ultrahigh-pressure, (U)HP, rocks of crustal origin appears to be ubiquitous during Phanerozoic plate subduction and continental collision events. Exhumation of (U)HP material has been shown in some orogens to have occurred only once, during a single short-lived event; in other cases exhumation appears to have occurred multiple discrete times or during a ...

Recent zircon-based geochronological investigations in the Adirondack Mountains, in the state of New York, demonstrate that 1155 ± 6 Ma massif anorthosite was emplaced during the post-contractional phase (1160–1140 Ma) of the ca. 1200–1140 Ma Shawinigan orogeny. Emplacement of many other anorthosite – mangerite – charnockite – granite (AMCG) suites also correlates with the waning stage of oroge...

Large and small volume rhyolites are generated in calderas and rift zones, inheriting older and isotopically diverse crystal populations from their volcanic predecessors. Low-dO values in many of these rhyolites suggest that they were derived from the remelting of solid, hydrothermally altered by meteoric water protoliths that were once close to the surface, but become buried by caldera collaps...

[1] The current structure of the South Armorican Domain in the French Variscan Belt, provides an excellent record of the late orogenic evolution, as documented by the complex interactions between extensional structures and partial melting. In the Golfe du Morbihan, the South Brittany Migmatite Belt (SBMB), tectonically overlain by non‐melted metamorphic units, was studied by combined structural...