layers of airborne pumice resulting from violent volcanic eruptions. Provide valuable dating markers when found in sites.
Sand-sized particles of igneous rock that form when a spray of liquid magma is blown from a volcanic vent by escaping gas.
A fine powder similar to diatomite but lighter in weight, it is used as a filter medium or filter aid in diatomite filters.
Dust-size particles ejected from a volcano.
A very fine, gritty volcanic dust whose particles are less than 4mm in diameter.
Fine particles of rock powder that originate from a volcano and that may remain suspended in the atmosphere for long periods.
A volcanic sediment of rock fragments, usually glass, less than 2 mm in diameter, that is formed when escaping gases force out a fine spray of magma.
Tiny glass shards formed when a fine spray of exploded lava freezes instantly upon contact with the atmosphere.
Small sized particles ejected from explosive volcanoes.
volcanic ejection from a volcanic explosion that is transported through the air and subsequently accumulates as layers on the earth's surface.
Fine unconsolidated pyroclastic matter (under 2mm in diameter). When consolidated, this material is called tuff.
Volcanic rock which is exploded from a vent in fragments less than 2mm in size. Ash may be solid or molten when first erupted.
Rock. Fine volcanic dust formed when gasses escaping from a volcano force a fine spray of magma into the air.
A volcanic sediment less than 4 mm in diameter, which is usually made of glass.
pyroclastic sediment with fragments of less than 4 mm in diameter.
The fine, dust-like, fragmentary rock material violently blown from volcanoes during explosive eruptions.
Fine particles of mineral matter from a volcanic eruption which can be dispersed long distances by winds aloft. The chemical composition and abrasiveness of the particles can seriously affect aircraft and also machinery on the ground. If it is blown into the stratosphere and it is thick enough, it can decrease the global temperature.
Powdered rock. Ash particles are defined as less than 4 millimetres in diameter.
Material in the form of small fragments from 0.06 to 4mm in diameter, blown out by a volcano.
Fine particles of lava ejected during a volcanic eruption. Sometimes the particles are shot high into the atmosphere and carried long distances by the wind.
finely pulverized pyroclastic material ejected from a volcano in eruption. [AHDOS
Volcanic ash consists of very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. Ash is created when solid rock shatters and magma separates into minute particles during explosive volcanic activity. The usually violent nature of an eruption involving steam (phreatic eruption) results in the magma and perhaps solid rock surrounding the vent, being torn into particles of clay to sand size.