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±...

The forecasting of lava flow paths is a complex problem in which temperature, rheology and flux-rate all vary with space and time. The problem is more difficult to solve when lava runs down a real topography, considering that the relations between characteristic parameters of flow are typically nonlinear. An alternative approach to this problem that does not use standard differential equation m...

Flood basalt flows of the Columbia River Basalt Group commonly exhibit well-developed colonnade and entablature structures formed during cooling of individual flows. The colonnade refers to the well-defined columnar structure of many flows, which appears in the lowermost 10% to 30% and, in places, the uppermost 10% to 20%. Entablature refers to those parts of a flow that have smaller column dia...

Some meteorites are pieces of lava flows. They have the expected minerals present and the crystals are intertwined in a characteristic way indicative of crystallization in a lava flow. This shows that lavas erupted on at least some asteroids. Age dating indicates that the eruptions took place 4.5 billion years ago. Planetary scientists have recognized three main groups of asteroidal lava flows,...

Over two hundred isolated outcrops of horizontally stratified, basaltic lava flows within the inner gorge of western Grand Canyon indicate that several natural “lava dams” blocked the flow of the Colorado River during the Pleistocene, resulting in the formation of several lakes within the canyon. The largest lake was 90 m above the high water level of present-day Lake Powell and backed up a dis...

SO2 emission rates from Erebus volcano show periodicity, which directly relates to lava lake convection and magma and conduit processes. Mt. Erebus is a 3794 m stratovolcano with a persistently degassing convecting, phonolite lava lake. Lava lake SO2 emission rates were collected from 1992 to 2003 using the correlation spectrometer (COSPEC) and in 2003 and 2005 using a miniature ultra-violet di...

[1] Volcano observatories and researchers are recognizing the potential usefulness of thermal imaging cameras both before and during volcanic eruptions. Obvious applications include measurements of the surface temperatures of active lava domes and lava flows to determine the location of the most active parts of these potentially hazardous features. If appropriate precautions are taken, the new ...

Pahoehoe lava flows are common in every basaltic province, and their submarine variants, pillow lavas and sheet flows, cover the bulk of the Earth. Pahoehoe flows are emplaced by inflation—the injection of molten lava underneath a solidified crust. Only in the past few years has an understanding of the inflation process and the ability to recognize ancient inflated lava flows been achieved. All...