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Sillar
Sillar is a variety of rhyolite, which is a type of volcanic rock. Although sillar is of rhyolitic composition, it has been erupted from volcanoes which mostly erupt andesite lava, and sillar contains small fragments of andesite. A pink variety of sillar owes its colour to crystals of hematite within the rock. A white variety lacks these hematite crystals. Sillar is found as pyroclastic flow deposits of tuff near volcanoes in southern Peru, for example the now-extinct Chachani volcano which erupted flows of sillar during the Pleistocene epoch. Sillar facies Orvieto-Bagnoregio Ignimbrite (black blocks of scoria in red tuff) occurs at Civita di Bagnoregio in the Vulsini volcanic district of central Italy.Palladino D.M. et al. (2014) ''Bolsena, Latera and Vico calderas, central Italy'', IAVCEI Field Guide Series 3, page 29 Building stone Sillar has been used as a building stone in Peru. Many colonial buildings in the city of Arequipa Arequipa (; Aymara and qu, Ariqipa) is a cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuff
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. 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''). Tuff composed of sandy volcanic material can be referred to as volcanic sandstone. Tuff is a relatively soft rock, so it has been used for construction since ancient times. Because it is common in Italy, the Romans used it often for construction. The Rapa Nui people used it to make most of the ''moai'' statues on Easter Island. Tuff can be classified as either igneous or sedimentary rock. It is usually studied in the context of igneous petrology, although it is sometimes described using sedimentological terms. Tuff is often erroneously called tufa in guidebooks and in television programmes. Volcanic ash The material that is expelled in a volcanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arequipa Yanahuara
Arequipa (; Aymara and qu, Ariqipa) is a city and capital of province and the eponymous department of Peru. It is the seat of the Constitutional Court of Peru and often dubbed the "legal capital of Peru". It is the second most populated city in Peru, after Lima, with an urban population of 1,008,290 inhabitants according to the 2017 national census. Its metropolitan area integrates twenty-one districts, including the foundational central area, which it is the seat of the city government. The city had a nominal GDP of US$9,445 million, equivalent to US$10,277 per capita (US$18,610 per capita PPP) in 2015, making Arequipa the city with the second-highest economic activity in Peru. Arequipa is also an important industrial and commercial center of Peru,Chanfreau, p. 40 and is considered as the second industrial city of the country. Within its industrial activity the manufactured products and the textile production of wool of camelids. The town maintains close commercial links wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Building Stone
Building material is material used for construction. Many naturally occurring substances, such as clay, rock (geology), rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, Building insulation, insulation, plumbing, and roofing material, roofing work. They provide the make-up of :Human habitats, habitats and architecture, structures including homes. The total cost of building materials In history, there are trends in building materials from being natural to becoming more man-made and Composite material, composite; biodegradable to imperishable; indigenous (local) to being transported globally; repairable to disposable; chosen for increased levels of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Rocks
Volcanic rock (often shortened to volcanics in scientific contexts) is a Rock (geology), rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of Volcano, volcanic origin. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into Subvolcanic rock, hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks. For these reasons, in geology, volcanics and shallow hypabyssal rocks are not always treated as distinct. In the context of Precambrian shield (geology), shield geology, the term "volcanic" is often applied to what are strictly metavolcanic rocks. Volcanic rocks and sediment that form from magma erupted into the air are called "volcaniclastics," and these are technically sedimentary rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate bound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arequipa
Arequipa (; Aymara and qu, Ariqipa) is a city and capital of province and the eponymous department of Peru. It is the seat of the Constitutional Court of Peru and often dubbed the "legal capital of Peru". It is the second most populated city in Peru, after Lima, with an urban population of 1,008,290 inhabitants according to the 2017 national census. Its metropolitan area integrates twenty-one districts, including the foundational central area, which it is the seat of the city government. The city had a nominal GDP of US$9,445 million, equivalent to US$10,277 per capita (US$18,610 per capita PPP) in 2015, making Arequipa the city with the second-highest economic activity in Peru. Arequipa is also an important industrial and commercial center of Peru,Chanfreau, p. 40 and is considered as the second industrial city of the country. Within its industrial activity the manufactured products and the textile production of wool of camelids. The town maintains close commercial links wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulsini
Vulsini, also known as Volsini volcano, Vulsini Volcanic District, Vulsini Volcanic Complex and the Vulsinian District, is a circular region of intrusive igneous rock in Lazio, Italy, about to the north northwest of Rome, containing a cluster of calderas known to have been active in recent geologic times. The Vulsinian region is one of dozens of intrusive circular regions, most smaller than the Vulsinian, arranged in a band from Campania through Lazio, called the Roman Comagmatic Province. A comagmatic province is a geologic area of the same type and age igneous rock deriving from the same crustal magma. The Roman region is post-collisional; that is, the intrusions were not a result of the lateral stresses that created Italy and raised the Apennines, but were subsequent to Italy's creation. The Volsinian is the northernmost region. At relatively low altitude, the Vulsini calderas cover about and contain four Pleistocene-age depressions known as Bolsena, Latera, Vepe and Montef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civita Di Bagnoregio
Civita di Bagnoregio is a town in the Province of Viterbo in central Italy, a ''suburb'' of the comune of Bagnoregio, east from it. It is about north of Rome. The only access is a footbridge from the nearby town, with a toll introduced in 2013. Due to the toll, communal taxes were abolished in Civita and nearby Bagnoregio. Due to its unstable foundation that often erodes, Civita is famously known as "the dying city". Territory Civita is situated in the valley of the badlands (''Valle dei Calanchi''), a region east of Lake Bolsena and west of the Tiber Valley, in the municipality of Bagnoregio. It consists of two main valleys: the ''Fossato del Rio Torbido'' and the ''Fossato del Rio Chiaro.'' Originally these places might have been easier to reach and were crossed by an ancient road which linked the Tiber Valley to Lake Bolsena. The morphology of this region was caused by erosion and landslides. The territory is made up of two different formations of rocks, different in ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scoria
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. It is typically dark in color (generally dark brown, black or purplish-red), and basaltic or andesitic in composition. Scoria is relatively low in density as a result of its numerous macroscopic ellipsoidal vesicles, but in contrast to pumice, all scoria has a specific gravity greater than 1, and sinks in water. The holes or vesicles form when gases that were dissolved in the magma come out of solution as it erupts, creating bubbles in the molten rock, some of which are frozen in place as the rock cools and solidifies. Scoria may form as part of a lava flow, typically near its surface, or as fragmental ejecta (lapilli, blocks and bombs), for inst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignimbrite
Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrounding atmosphere. New Zealand geologist Patrick Marshall (1869-1950) coined the term ''ignimbrite'' from the Latin ''igni-'' [fire] and ''imbri-'' [rain]. Ignimbrites are made of a very poorly sorted mixture of volcanic ash (or tuff when Lithification, lithified) and pumice lapilli, commonly with scattered lithic fragments. The ash is composed of glass shards and crystal fragments. Ignimbrites may be loose and unconsolidated, or lithified (solidified) rock called lapilli-tuff. Near the volcanic source, ignimbrites often contain thick accumulations of lithic blocks, and distally, many show meter-thick accumulations of rounded cobbles of pumice. Ignimbrites may be white, grey, pink, beige, brown, or black depending on their composition and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formation), and the changes that may occur in those attributes over a geographic area. A facies encompasses all of the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock. The term facies was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy, which replaced the earlier notions of Neptunism. Types of facies Sedimentary facies Ideally, a Sedimentary structures, sedimentary facies is a distinctive rock unit that forms under certain conditions of sedimentation, reflecting a particular process or environment. Sedimentary facies are either descriptive or interpretative. Sedimentary facies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chachani
Chachani is a volcanic group in southern Peru, northwest of the city of Arequipa. Part of the Central Volcanic Zone of the Andes, it is above sea level. It consists of several lava domes and individual volcanoes such as Nocarane, along with lava shields such as the Airport Domes. Underneath Chachani lies a caldera. During the Pliocene and early Pleistocene, the volcanic group produced large ignimbrites such as the La Joya, Arequipa Airport and Yura Tuff ignimbrites; afterwards the volcanic group proper grew in the caldera until about 56,500 years ago. There have not been any eruptions during historical time, but the volcano is considered to be only dormant and due to its closeness to the city of Arequipa is considered high risk. Name The name means "brave" in Aymara or "mountain of man"/"mountain of male"; alternative spellings "Cacheni" and "Charchani" are also known. Geography and geomorphology The volcano lies in the Andes of southern Peru, northwest of Arequipa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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