More than 50 conspicuous tephra beds occur in the Kanguk Formation of SW Banks Island. Their glass shards are remarkably well preserved and permit comprehensive characterization offering potential for reliable, precise correlation Upper Cretaceous sedimentary rocks across three major depocentres Arctic Archipelago adjacent northern continental margin: Sverdrup, Banks, Beaufort-MacKenzie basins....

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...

The analysis of magmatic distribution, basin formation, tectonic evolution and structural styles of different segments of the Andes shows that most of the Andes have experienced a stage of flat subduction. Evidence is presented here for a wide range of regions throughout the Andes, including the three present flat-slab segments (Pampean, Peruvian, Bucaramanga), three incipient flat-slab segment...

S U M M A R Y We present a model for flow and seepage in a deforming, shear-dilatant sensitive porous layer that enables estimates of the excess pore fluid pressures and flow rates in both the melt and solid phase to be captured simultaneously as a function of stress rate. Calculations are relevant to crystallizing magma in the solidosity range 0.5–0.8 (50–20 per cent melt), corresponding to a ...

Abstract We present a detailed petrologic study of rhyolites from seven eruptions spanning the full (?190 ky) history rhyolitic volcanism at Krafla volcano, northeast Iceland. The vary widely in size and style, but all are crystal-poor (<6 modal%: plagioclase + augite ± pigeonite orthopyroxene titanomagnetite fayalite) have similar evolved compositions (73.7–75.8 wt% normalized whole-roc...

Giant volcanic eruptions have the potential to overturn civilizations. Yet, driving mechanism and timescale over which batholithic magma reservoirs transition from non-eruptible crystal mush mobile melt-dominated stages our capacity detect a pending super-eruption remain obscure. Here we show, using Sr isotope zonation in plagioclase crystals three Andean large-magnitude (Atana, Toconao, Tara i...

Relevant data on the structure and composition of crystalline basement in Central México can be found by means plutonic, metamorphic, sedimentary xenoliths transported Neogene Quaternary volcanic eruptions within Trans-Mexican Volcanic Belt (TMVB). We present detailed major oxide trace elements concentrations, isotopic analysis thermobarometric estimations for a granitic xenolith an Early Mioce...

We present a full characterization of 20 cm-thick tephra layer found intercalated in the marine sediments recovered at Site U1524 during International Ocean Discovery Program (IODP) Expedition 374, Ross Sea, Antarctica. Tephra bedforms, mineral paragenesis, and major- trace-element composition on individual glass shards were investigated age was constrained by 40Ar-39Ar sanidine crystals. The d...