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Tuffite is a tuff containing both pyroclastic and detrital materials, but predominantly pyroclasts. According to the IUGS definition, tuffite contains 75% to 25% volcanic (epiclastic) material. [1] There are several classifications that define tuffite. The classification in the IUGS recommendation is based on the definition established by ...
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 greater than 75% ash is considered tuff, while rock containing 25% to 75% ash is described as tuffaceous (for example, tuffaceous sandstone). [3]
In geology, texture or rock microstructure [1] refers to the relationship between the materials of which a rock is composed. [2] The broadest textural classes are crystalline (in which the components are intergrown and interlocking crystals), fragmental (in which there is an accumulation of fragments by some physical process), aphanitic (in which crystals are not visible to the unaided eye ...
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Volcanic rocks are named according to both their chemical composition and texture. Basalt is a very common volcanic rock with low silica content. Rhyolite is a volcanic rock with high silica content. Rhyolite has silica content similar to that of granite while basalt is compositionally equal to gabbro.
Texture is an important criterion for the naming of volcanic rocks. The texture of volcanic rocks, including the size, shape, orientation, and distribution of mineral grains and the intergrain relationships, will determine whether the rock is termed a tuff, a pyroclastic lava or a simple lava.
Opus reticulatum (also known as reticulate work) is a facing used for concrete walls in Roman architecture from about the first century BCE to the early first century CE. [1]: 136–9 [notes 1] They were built using small pyramid shaped tuff, a volcanic stone embedded into a concrete core.
Lavas may preserve a flow foliation, or even compressed eutaxitic texture, typically in highly viscous felsic agglomerate, welded tuff and pyroclastic surge deposits. Metamorphic differentiation, typical of gneisses, is caused by chemical and compositional banding within the metamorphic rock mass.