Search results
Results from the WOW.Com Content Network
Tephra is a generalized word for the various bits of debris launched out of a volcano during an eruption, regardless of their size. [4] Pyroclastic materials are generally categorized according to size: dust measures at <1/8 mm, ash is 1/8–2 mm, cinders are 2–64 mm, and bombs and blocks are both >64 mm. [5] Different hazards are associated with the different kinds of pyroclastic materials.
Following a 1.5-million-year hiatus with few eruptions, a bimodal volcanic field of basalt lava flows and rhyolite lava domes and flows developed on Basin and Range terrain of essentially the same form as today's landscape. Many of the young basalt flows are inter-canyon, occupying parts of the present-day drainage system.
The word lava comes from Italian and is probably derived from the Latin word labes, which means a fall or slide. [2] [3] An early use of the word in connection with extrusion of magma from below the surface is found in a short account of the 1737 eruption of Vesuvius, written by Francesco Serao, who described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of ...
The word 'malpaís' in Spanish translates to "badland," and this describes the area as being extremely rough and difficult to traverse and unusable for crops.Although a malpaís is often another word for the badlands that form by erosion of sedimentary rocks in the same environment, a malpaís is often associated with such types of lava plain terrain as found in a volcanic field.
Flood basalt commonly displays columnar jointing, formed as the rock cooled and contracted after solidifying from the lava.The rock fractures into columns, typically with five to six sides, parallel to the direction of heat flow out of the rock.
The fire’s push northward has brought it toward the rugged lava rock landscape surrounding Lassen Volcanic National Park, which has been closed because of the threat. The area remains one of the ...
Vast areas of trap rock in the form of thick lava flows and other volcanic rocks comprise the Deccan Traps of India and Siberian Traps of Russia. [6] Other prominent basalt ridges, mountains, buttes, canyons, and other landscape features include: In North America: The ridges and cliffs of the Columbia River Gorge in Oregon and Washington.
The terms lava stone and lava rock are more used by marketers than geologists, who would likely say "volcanic rock" (because lava is a molten liquid and rock is solid). "Lava stone" may describe anything from a friable silicic pumice to solid mafic flow basalt, and is sometimes used to describe rocks that were never lava, but look as if they ...