introduction hornblende-bearing gabbroic rocks are quite common in subduction-related magmatic suites and considered to represent magmatic differentiation process in arc magmas (heliker, 1995; hickey-vargas et al., 1995; mandal and ray, 2012). the presence of hornblende as an important mineral phase in gabbroic rocks of subduction zone has been considered either as an early crystallizing minera...

Northeast Queensland contains multiple slices of mafic–ultramafic units, strung out along regional faults that mark major tectonic boundaries. One such complex is the Cowley Ophiolite Complex, which situated Russell-Mulgrave Fault. The Complex a differentiated composed gabbro, chlorite schist, anthophyllite schist and serpentinite. We interpret alteration assemblages observed throughout reflect...

The conventional K-Ar dating method was applied to the 1986 dacite flow from the new lava dome at Mount St. Helens, Washington. Porphyritic dacite which solidified on the surface of the lava dome in 1986 gives a whole rock K-Ar “age” of 0.35±0.05 million years (Ma). Mineral concentrates from the dacite which formed ins 1986 give K-Ar “ages” from 0.34±0.06 Ma (feldspar-glass concentrate) to 2.8±...

This paper describes the localization of deformation acceleration in the period prior to dynamic failure in hornblende schist rock under triaxial compression using acoustic emission (AE) monitoring. Rather than stabilize the failure process by controlling axial stress to maintain a constant rate of AE (for monitoring AE hypocenters) as in previous works [e.g., Lockner et al., 1991], we have ins...

The Wadi Hodein area contains a wide variety of late Precambrian igneous and metamorphic rocks, represented by gneisses, serpentinites, metagabbros, metasediments, metavolcanics, metagabbro-diorite, granodiorite and granitoids. The Wadi Hodein metavolcanics (WHV), including G. Khashab and G. El Anbat, represent one of the significant metavolcanic suites in the southern part of the Nubian Shield...