Breccia in the context of "Lithic fragment (geology)"

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⭐ Core Definition: Breccia

Breccia (/ˈbrɛ(t)ʃiə/ BRETCH-ee-ə, BRESH-; Italian: [ˈbrettʃa]; Italian for 'breach') is a clastic rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix.

The word has its origins in the Italian language, in which it means 'rubble'. A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, fault or tectonic breccia, igneous breccia, impact breccia, and hydrothermal breccia.

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Breccia in the context of Volcaniclastic rock

Volcaniclastics are geologic materials composed of broken fragments (clasts) of volcanic rock. These encompass all clastic volcanic materials, regardless of what process fragmented the rock, how it was subsequently transported, what environment it was deposited in, or whether nonvolcanic material is mingled with the volcanic clasts. The United States Geological Survey defines volcaniclastics somewhat more narrowly, to include only rock composed of volcanic rock fragments that have been transported some distance from their place of origin.

In the broad sense of the term, volcaniclastics includes pyroclastic rocks such as the Bandelier Tuff; cinder cones and other tephra deposits; the basal and capping breccia that characterize ʻaʻā lava flows; and lahars and debris flows of volcanic origin.

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Breccia in the context of Cementation (geology)

Cementation is a process where minerals bond grains of sediment together by growing around them. This means precipitation of ions carried in groundwater to form new crystalline material between sedimentary grains. The new pore-filling minerals form "bridges" between original sediment grains, thereby binding them together. In this way, sand becomes sandstone, and gravel becomes conglomerate or breccia.

Cementation occurs as part of the diagenesis or lithification of sediments and occurs primarily below the water table regardless of sedimentary grain sizes present. Large volumes of pore water must pass through sediment pores for new mineral cements to crystallize and so millions of years are generally required to complete the cementation process. Common mineral cements include calcite, quartz, and silica phases like cristobalite, iron oxides, and clay minerals; other mineral cements also occur.

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Breccia in the context of Big Raven Plateau

The Big Raven Plateau is an intermontane plateau in Cassiar Land District of northwestern British Columbia, Canada. It lies on the Tahltan Highland and is surrounded by several valleys, including those of Mess Creek, Kakiddi Creek, Chakima Creek, Walkout Creek and the Klastline River. The plateau is drained by many small streams that flow into these neighbouring valleys and, unlike the neighbouring valleys, it is relatively barren of vegetation. Stream erosion has resulted in the creation of canyons with intervening ridges on the eastern and western sides of the Big Raven Plateau. The plateau is in Mount Edziza Provincial Park, which is one of the largest provincial parks in British Columbia. Access to the Big Raven Plateau is mainly by aircraft or by a network of horse trails from surrounding roads.

The Big Raven Plateau is volcanic in origin, consisting mostly of basaltic lava flows of the Mount Edziza volcanic complex that were erupted in the last 7.5 million years. These lava flows are interbedded with rhyolite and trachyte which are in the form of rock fragments produced and ejected by explosive eruptions. The dominant feature on the Big Raven Plateau is Mount Edziza, an ice-covered stratovolcano reaching an elevation of 2,786 metres (9,140 feet). Its composition is more diverse, consisting of alkali basalt, hawaiite, trachybasalt, tristanite, mugearite, benmoreite, trachyte and rhyolite which are in the form of lava flows, lava domes and breccia. The Big Raven Plateau is subdivided into at least 10 geological formations, each being the product of a distinct period of volcanic activity.

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Breccia in the context of Carbonatite

Carbonatite (/kɑːrˈbɒnəˌtt/) is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. Carbonatites may be confused with marble and may require geochemical verification.

Carbonatites usually occur as small plugs within zoned alkalic intrusive complexes, or as dikes, sills, breccias, and veins. They are almost exclusively associated with continental rift-related tectonic settings. It seems that there has been a steady increase in the carbonatitic igneous activity through the Earth's history, from the Archean eon to the present.

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Breccia in the context of Gladysvale

Gladysvale Cave is a fossil-bearing breccia filled cave located about 13 kilometres (8.1 mi) northeast of the well-known South African hominid-bearing sites of Sterkfontein and Swartkrans and about 45 kilometres (28 mi) north-northwest of Johannesburg, South Africa. It is situated within the Cradle of Humankind World Heritage Site and is itself a South African National Heritage Site.

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Breccia in the context of KREEP

KREEP, an acronym built from the letters K (the atomic symbol for potassium), REE (rare-earth elements) and P (for phosphorus), is a geochemical component of some lunar impact breccia and basaltic rocks. Its most significant feature is somewhat enhanced concentration of a majority of so-called "incompatible" elements (those that are concentrated in the liquid phase during magma crystallization) and the heat-producing elements, namely radioactive uranium, thorium, and potassium (due to presence of the radioactive K).

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Breccia in the context of Hadley Rille

Hadley–Apennine is a region on the near side of Earth's Moon that served as the landing site for the American Apollo 15 mission, the fourth crewed landing on the Moon and the first of the "J-missions", in July 1971. The site is located on the eastern edge of Mare Imbrium on a lava plain known as Palus Putredinis. Hadley–Apennine is bordered by the Montes Apenninus (often referred to as "Apennine Front"), a mountain range, and Hadley Rille, a meandering channel, on the east and west, respectively.

Data obtained from the composition of soil samples collected on Apollo 15 show that most (about 90%) of the samples from the Apennine Front are brown-glass breccias, and approximately 60–70% obtained from the mare surface are basalt. Although the basalts seem to vary in their texture, their ages appear to be approximately the same. Most of the samples obtained on the Apennine Front are KREEP (potassium, rare-earth elements, phosphorus) materials, anorthosites, recrystallized norite, or recrystallized breccia.

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