The 2012 Havre submarine eruption produced a 1.5 km 3 bulk rock volume or 0.52 dense equivalent of rhyolite emplaced as minor lava flows, field sunken seafloor pumice, and volumetrically dominant pumice raft. This moderately large medium-K (1.4–1.6 wt% K 2 O) is relatively chemically homogeneous (71.5–73.0 SiO ), no trace element variation cryptic zoning has been detected despite the textural d...

Pumice pebbles were collected by staff of the Marshall Islands Historic Preservation Office (RMIHPO) during a 2005 cultural inventory of Jelbon Islet, Mili Atoll. GNS Science analyzed the major and trace element chemistry and found a close match with analyses of the alkali-rich rhyolite erupted in 1953-1957 from Tuluman Island, Admiralty group, Papua New Guinea some 3000 km from Mili Atoll. The...

During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples examined consist of basaltic ash and scoria plastered onto a conduit wall of a coherent rhyolite dome and a welded rhyolitic dome breccia. We exami...

A voluminous ([600 km) and long-lived (*520–75 ka) phase of rhyolitic eruptions followed collapse of the Yellowstone caldera 640 ka. Whether these eruptions represent a dying cycle, or the growth of a new magma chamber, remains an important question. We use new U–Th zircon ages and dO values determined by ion microprobe, and sanidine Pb isotope ratios determined by laser ablation, to investigat...

ABSTRACT The peraluminous rhyolite that forms Round Top Mountain (approximately 375 m high × nearly 2 km in diameter), near Sierra Blanca, Hudspeth County, west Texas, USA, is enriched in yttrium and heavy rare earth elements (YHREEs), as well as Li, Be, U, Th, Sn, F, Rb, Cs, Nb, and Ta. Texas Mineral Resources Corp. (USA) proposes to release the YHREEs from their unique yttrofluorite host via ...

Accurate forecasts of lava flow length rely on estimates of eruption andmagma properties and, potentially more challengingly, on an understanding of the relative influence of characteristics such as the apparent viscosity, the yield strength of the flow core, or the strength of the lava’s surface crust. For basaltic lavas, the relatively high frequency of eruptions has resulted in numerous oppo...