In the Central IranianVolcanic Belt (CIVB), north-west of Shahre-Babak, in the area of Javazm, Dehaj and khabr, about 60 subvolcanic porphyritic dacitic to rhyodacitic domes (1-10 km2) are intruded into a variety of rock sequences from Mesozoic to Early Miocene in age. These rocks are a part of Dehaj-Sardoieh belt. The CIVB contains intrusive and extrusive rocks of Cretaceous-Quaternary age. Ge...

Thick, slow-moving block-lava flows are associated with extrusive activity in dacitic systems, where lava-core depressurization during flow-front collapse generates devastating block-and-ash flows. Dimensional and rare thermal data collected during January 2000 for an active dacitic block flow at Santiaguito (Guatemala) provide insight into cooling and emplacement mechanisms. Flow velocity was ...

Abstract We examine the connected history of dacite-dominant volcanic rocks Tschicoma Formation, erupted between 5.5 and 2 Ma from Jemez Mountains field, western USA. Zircon samples two separate eruptions have continuous SHRIMP U–Pb age spectra spanning 0.84–1.08 Myr duration (3.12–3.96 3.50–4.58 Ma, respectively), following an episode zircon crystallization 0.28–0.50 earlier (at 4.46 4.86 resp...

Magmas with matrix glass compositions ranging from basalt to dacite erupted a series of 24 fissures in the first 2 weeks 2018 Lower East Rift Zone (LERZ) eruption K?lauea Volcano. Eruption styles ranged low spattering and fountaining strombolian activity. Major element trajectories glasses melt inclusions hosted by olivine, pyroxene plagioclase are consistent variable amounts fractional crystal...

We present the late Holocene eruption history of poorly known Doña Juana volcanic complex, in SW Colombia, which last erupted twentieth century. This represents a case study for potentially active volcanism rural Northern Andes, where tropical climate conditions and fragmented social memory blur record dormant volcanoes. reconstructed stratigraphy central-summit vent area by integrating new map...

Several processes have been proposed as triggering mechanisms for the large sector collapses that affect most volcanoes, and which may occur several times in volcano's lifetime. Here we present discuss case of Tutupaca volcano, located southern Peru part Central Volcanic Zone Andes. is composed an old, hydrothermally altered highly eroded Basal edifice, well younger twin peaks northern complex ...