A rock composed of the finer kinds of volcanic detritus, usually fused together by heat.
A sedimentary rock composed of fine material explosively ejected from a volcano and subsequently compacted to a solid mass.
A volcanic rock made up of consolidated ash.
Compacted (lithified) volcanic ash. There are a number of tuff layers in Fossil Lake sediments, indicating the region underwent a certain amount of volcanism during the life of the lake. These layers are important in dating the lake since it is from these sediments samples can be obtained for radiometric dating. Such volcanic material is considered to be "frozen in time" at the instant the minerals within them crystallized whereas sedimentary rocks are the products of the deterioration of preexisting material and are subject to weathering and erosion which corrupts the closed system required by absolute dating techniques. The K-spar tuff layers in Fossil Basin contain a high percentage of potassium (K) feldspar.
Rocks consolidated from volcanic material containing a predominance of fragments not greater than 2 cm in diameter.
A pyroclastic igneous rock composed of volcanic ash and fragmented pumice, formed when accumulations of the debris cement together.
A consolidated form of volcanic ash (qv) or lapilli (qv).
a rock comprised of compacted volcanic fragments
A rock composed of pyroclastic materials that have been ejected from a volcano. In many instances these fragments are still hot when they land, producing a "welded" rock mass.
A consolidated rock composed of pyroclastic volcanic rock made up of rock and mineral fragments in a volcanic ash matrix. Tuffs commonly are composed of much shattered volcanic rock glass--chilled magma blown into the air and then deposited. If volcanic particles fall to the ground at a very high temperature, they may fuse together, forming a welded tuff.
Porous igneous rock composed of volcanic ash compacted together.
A collective term used for describing all consolidated pyroclastic materials.
a general term for all consolidated pyroclastic rocks, but often used for the finer grained variation.
A general term for all consolidated pyroclastic deposits. If the ash builds up on the surface and is still very hot, it may fuse together in the heat and become flattened under its own weight forming welded tuff, like this example from Chiricahua National Monument in Arizona.
hard volcanic rock composed of compacted volcanic ash
a porous rock created by a consolidation of volcanic ash
Rock. A volcanic rock composed of pyroclastic fragments, fine ash, or both. The particles may be melted slightly by the volcanic heat to produce a welded tuff.
term used for a compacted extrusive pyroclastic deposit of volcanic ash and/or dust.
Rock formed of pyroclastic material.
A general term for all pyroclastic rocks, not to be confused with tufa.
Term used for volcanic ash that has been consolidated and cemented.
Cemented volcanic ash; many varieties included.
A consolidated rock composed of pyroclastic fragments and fine ash. If particles are melted slightly together from their own heat, it is a "welded tuff.". A general term for all consolidated pyroclastic rocks, but usually referring to the finer-grained variety; the coarser variety usually is called volcanic breccia.
Volcanic rock of compacted medium to fine-grained pyroclastic material.
Rock composed of fine volcanic ash.
Ash and other ejecta which has consolidated into a rock deposit.
Rock composed of volcanic particles, ranging from ash size to small pebble size, compacted or cemented or welded to firm, consolidated state.
geological formation composed of compressed volcanic ash.
A general term for all consolidated pyroclastic material, but typically refers to volcanic ash.
Volcanic ash, particles of 4 mm diameter or smaller.
n. A general term for consolidated rocks made of material ejected from volcanic explosions.
consolidated rock deriving from volcanic ashes and composed of crystals, lapilli and glass shards.
Consolidated or cemented volcanic ash. Sometimes used as a general term for all consolidated pyroclastic rocks.
volcanic rock formed as a result of the consolidation of volcanic ash and dust
The general term for consolidated pyroclastic debris.
Deposits of volcanic ash that have formed a crust-like layer over the underlying land.
A rock formed from volcanic ash fall deposits;
Tuff is pyroclastic rock.
A rock formed of compacted volcanic fragments. A general term for all consolidated pyroclastic rocks.
a rock produced by the consolidation of volcanic ash and other volcanic fragments. [AHDOS
Tuff (from the Italian "tufo") is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. (Note that tuff is a type of rock entirely different from tufa.)