One of the fundamental geophysical observations made of the Earth is the stratified nature of the continental crust, in which the lower crust comprises denser, more mafic material and the upper crust comprises less dense, more felsic material. This chemically differentiated layered structure is developed and maintained by partial melting at depth and the ascent of magma to shallower crustal lev...

Three tectono-magmatic systems create volcanism in Central America; the volcanic front, a weak secondary front and the back-arc. Most magma output occurs at the volcanic front along narrow lines of historically active composite volcanoes in strikeslip/extensional settings. Lavas have strong slab signature, are water-rich and plagioclase and pyroxene phyric. A sporadic secondary front occurs abo...

Multiple volcanic eruptions occurred between 8500 and 9000 yr. B.P. from the central crater of CitiaitCpetl Volcano generating a series of pyroclastic flows that formed a deposit with a total volume of about 0.26 km3 (D.R.E.). The flows descended in all directions around the crater, but they were mostly controlled by topography and deposited in valleys or local topographic depressions up to abo...

Igneous sheet intrusions are a fundamental component of volcano plumbing systems. Identifying how intrusion emplacement and geometry controls later magmatic processes is critical to understanding the distribution volcanic eruptions magma-related ore deposits. Using Younger Giant Dyke Complex (YGDC), Mesoproterozoic suite large (<800 m wide) mafic dykes in southern Greenland, we assess influence...

Geochemical, isotopic and age constraints support a comagmatic origin for Ghuweir Mafics and the Feinan A-type granites. The two rocks types, named collectively in this paper as the Feinan Ghuweir Magmatic Suite (FGMS), formed between 556 and 572Ma ago according to Rb–Sr whole-rock dating. FGMS has low Sr initial ratios, which preclude a significant contribution of much older crust in the magma...

Non-traditional stable isotopes have increasingly been applied to studies of igneous processes including planetary differentiation. Equilibrium isotope fractionation of these elements in silicates is expected to be negligible at magmatic temperatures (δ(57)Fe difference often less than 0.2 per mil). However, an increasing number of data has revealed a puzzling observation, e.g., the δ(57)Fe for...