In continental arcs the extension of geothermal gradients derived from shallow crustal levels to depth predicts widespread melting at pressures that are inconsistent with seismic studies. Numerical models of low-pressure metamorphism in continental arcs suggest that these extrapolations are problematic because magmatic advection is the dominant mechanism of heat transport in these terranes rath...

The P-T conditions of both equilibria were determined precisely by reversal experiments in a piston-cylinder apparatus. On the basis of 8 experiments, brackets for the rutile-magnesite-geikielite equilibrium are 7.0–7.1 kbar at 800 ∞C, 8.6–8.7 kbar at 850 ∞C, and 10.5–10.7 kbar at 900 ∞C. On the basis of 9 experiments, brackets for the zircon-magnesite-baddeleyite-forsterite equilibrium are 7.1...

three granitoid bodies, shirkuh batholith, kaffe abad and ader bolandan are exposed in nw yazd, cutting across the naiband formation (upper triassic), and overlain by cretaceous formations. shirkuh batholith is most likely of jurassic age. it seems to be the first and the most significant episode of magmatism in studied area which occurred in middle jurassic (late cimmerian) time. on the other ...

Shirozulite is a new Mn-dominant trioctahedral mica from the Taguchi mine, Aichi Prefecture, Japan. The mineral occurs in tephroite-rhodochrosite ores in contact with a Ba-bearing, K-feldspar vein. Shirozulite formed during regional low-P/T metamorphism and, thereafter, suffered thermal metamorphism from a local granodiorite. Grains of shirozulite are up to 0.5 mm across and have a typical mica...

TEM and XRD techniques were used to study crystal growth characteristics of the fabric-forming phyllosilicates which developed in response to low-grade metamorphism and tectonic imbrication in part of the Southern Uplands thrust terrane. Prograde regional metamorphism, ranging from late diagenesis through the anchizone to the epizone, was accompanied by the development of a slaty cleavage which...

Metamorphism associated with orogenesis provides a mineral record that may be inverted to yield ambient apparent thermal gradients. On modern Earth, tectonic settings with lower thermal gradients are characteristic of subduction zones whereas those with higher thermal gradients are characteristic of backarcs and orogenic hinterlands. The duality of thermal environments reflects the asymmetry of...

Spectroscopic evidence of the thermally induced generation of multifunctional mesoporous materials through metamorphism within the pore walls of ethenylene-bridged PMOs is presented.