This paper summarizes results of a study of porosity, permeability, microstructure and acoustic properties of volcanic and pyroclastic rocks fromCampi Flegrei (CF) andMt. Etna (ET), Italy. We have measured the hydraulic, transport and acoustics properties of 28 room-dry samples at ambient conditions, 25 room-dry samples under confining pressure (up to 60 MPa) and 5 brine saturated samples under...

The facies changes, tectonics and magmatism across the Triassic–Jurassic boundary in the southern Tethyan margin have been studied in Egypt, Sudan, Jordan and Saudi Arabia. In Saudi Arabia and Jordan an unconformable contact is recognized between the Upper Triassic and Lower Jurassic rocks. This unconformity surface is marked by the truncation of the fluvial clastics of the uppermost Triassic b...

Palaeoproterozoic high-K I-type granites, high-level porphyry intrusions, and felsic volcanic rocks of the Whitewater Volcanics dominate the Hooper and Lamboo Complexes in the Kimberley region of northwestern Australia. The granites, porphyries and volcanic rocks are gradational into each other in the field, and they have the same mineralogy, similar major and trace element abundances, and indi...

kuh-e-siah is located in the north of gavkhuni lagoon and east of the varzaneh (se of isfahan) and is a part of urumieh-dokhtar magmatic arc (udma). the volcanic rocks of this area are vesicular basalt and basaltic andesite with late miocene age. the most common textures of these rocks are porphyry, microlitic porphyritic, hyaloporphyric and vesicular. plagioclase, olivine and clinopyroxene are...

misho intrusions outcrop in the southern part of north tabriz fault, east misho mountains, nw tabriz. filed studies, petrological and geochemical data show that both mafic and felsic rock types occur in the area. mafic rocks include gabbro consisting of plagioclase, clinopyroxene, olivine and opaque minerals and felsic bodies consist of alkali granite with k-feldspar, quartz, plagioclase and a ...

The Rooiberg Group is a 6-km-thick sequence of mostly volcanic rocks, which represent the first phase of magmatic activity associated with the Bushveld Complex. These strata include, in ascending stratigraphic order, the Dullstroom, Damwal, Kwaggasnek, and Schrikkloof Formations. Units of the lower Dullstroom Formation range from basalts to andesites and comprise two compositional suites: high ...

Potassium-argon ages of eight volcanic rocks from some of the geologically oldest flows exposed in the Galápagos Archipelago indicate that the Galápagos Islands have a probable maximum age of 3 million years. Rocks from six islands were dated; the oldest are from Española (3.2 +/- 0.2), Sante Fe (2.7 +/- 0.1), and Plazas (4.2 +/- 1.8 million years). The new data suggest that the Galápagos Islan...

Subduction-related volcanism in the northern part of the North Island of New Zealand shifted abruptly during the late Pliocene. This study focuses on the transition, in time and space, from the NNW-oriented Miocene–Pliocene Coromandel Volcanic Zone to the northeast-oriented active Taupo Volcanic Zone. The volcanic rocks marking this transition are exposed in the Tauranga Basin and adjacent Kaim...