Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. [1] [2] Rock that contains …

A pyroclastic-rock where there is at least 25% of each of the main fragment size divisions (i.e. block/bomb, lapilli and ash.)

2018年6月1日 · In the igneous breccia, the first sub-class is known as volcanic-breccia (or volcaniclastics) which can further be subdivided into flow-breccia and tuff-breccia, based on …

Tuff or ash tuff: a pyroclastic rock in which ash > 75%. Tuff may be further divided into coarse (ash) tuff (2 mm to 1/16 mm) and fine (ash) tuff (less than 1/16 mm). The fine ash tuff may also …

Phreatomagmatic tuff breccia from Germany. Phreatomagmatic eruption is an explosive volcanic eruption caused by interaction of ground water and magma3. Width of view is 12 cm. Tuff is …

Green to gray volcanic rock fragments (a breccia) with no visible crystals and lacks pores or gas bubbles. This sample consists of tightly fused and compacted volcanic tuff, and possibly …

exposed in the Po Toi islands to the southeast. The breccia horizons and crude bedding indicate a general northwestward dip. Flow-foliated lava clasts may reach up to 150 mm in diameter …

A pyroclastic texture shows a mixture of rock fragments, pumice, and volcanic ash. The ash is very fine grained, so only the rock fragments and pumice are identifiable. A rock with a …

2001年11月1日 · The intrusive tuff breccia, which encloses a megaclast of the host tuff breccia, is distinguished by abundant basaltic clasts and a dark gray, carbonaceous matrix. This intrusive …

A pyroclastic rock consisting of more or less equal amounts of ash, lapilli, and larger fragments. Click here to see list of references, authorities, sources and geographical terms as used in this …