Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix that can be similar to or different from the composition of the fragments. The word has its origins in the Italian language, in which it means either "loose gravel" or "stone made by cemented gravel". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia, hydrothermal breccia. Sedimentary breccia is a type of clastic sedimentary rock, made of angular to subangular, randomly oriented clasts of other sedimentary rocks. A conglomerate, by contrast, is a sedimentary rock composed of rounded fragments or clasts of pre-existing rocks. Both breccia and conglomerate are composed of fragments averaging greater than 2 millimetres in size; the angular shape of the fragments indicates that the material has not been transported far from its source. Sedimentary breccia consists of angular, poorly sorted, immature fragments of rocks in a finer grained groundmass which are produced by mass wasting.
It is lithified scree. Thick sequences of sedimentary breccia are formed next to fault scarps in grabens. Breccia may occur along a buried stream channel where it indicates accumulation along a juvenile or flowing stream. Sedimentary breccia may be formed by submarine debris flows. Turbidites occur as fine-grained peripheral deposits to sedimentary breccia flows. In a karst terrain, a collapse breccia may form due to collapse of rock into a sinkhole or in cave development. Fault breccia results from the grinding action of two fault blocks. Subsequent cementation of these broken fragments may occur by means of the introduction of mineral matter in groundwater. Igneous clastic rocks can be divided into two classes: Broken, fragmental rocks associated with volcanic eruptions, both of the lava and pyroclastic type. Volcanic pyroclastic rocks are formed by explosive eruption of lava and any rocks which are entrained within the eruptive column; this may include rocks plucked off the wall of the magma conduit, or physically picked up by the ensuing pyroclastic surge.
Lavas rhyolite and dacite flows, tend to form clastic volcanic rocks by a process known as autobrecciation. This occurs when the thick, nearly solid lava breaks up into blocks and these blocks are reincorporated into the lava flow again and mixed in with the remaining liquid magma; the resulting breccia is uniform in rock chemical composition. Lavas may pick up rock fragments if flowing over unconsolidated rubble on the flanks of a volcano, these form volcanic breccias called pillow breccias. Within the volcanic conduits of explosive volcanoes the volcanic breccia environment merges into the intrusive breccia environment. There the upwelling lava tends to solidify during quiescent intervals only to be shattered by ensuing eruptions. Clastic rocks are commonly found in shallow subvolcanic intrusions such as porphyry stocks and kimberlite pipes, where they are transitional with volcanic breccias. Intrusive rocks can become brecciated in appearance by multiple stages of intrusion if fresh magma is intruded into consolidated or solidified magma.
This may be seen in many granite intrusions where aplite veins form a late-stage stockwork through earlier phases of the granite mass. When intense, the rock may appear as a chaotic breccia. Clastic rocks in mafic and ultramafic intrusions have been found and form via several processes: Consumption and melt-mingling with wall rocks, where the felsic wall rocks are softened and invaded by the hotter ultramafic intrusion. Impact breccias are thought to be diagnostic of an impact event such as an asteroid or comet striking the Earth and are found at impact craters. Impact breccia, a type of impactite, forms during the process of impact cratering when large meteorites or comets impact with the Earth or other rocky planets or asteroids. Breccia of this type may be present on or beneath the floor of the crater, in the rim, or in the ejecta expelled beyond the crater. Impact breccia may be identified by its occurrence in or around a known impact crater, and/or an association with other products of impact cratering such as shatter cones, impact glass, shocked minerals, chemical and isotopic evidence of contamination with extraterrestrial material.
An example of an impact breccia is the Neugrund breccia, formed in the Neugrund impact. Hydrothermal breccias form at shallow crustal levels between 150 and 350 °C, when seismic or volcanic activity causes a void to open along a fault deep underground; the void draws in hot water, as pressure in the cavity drops, the water violently boils. In addition, the sudden opening of a cavity causes rock at the sides of the fault to destabilise and implode inwards, the broken rock gets caught up in a churning mixture of rock and boiling water. Rock fragments collide with each other and the sides of the void, the angular fragments become more rounded. Volatile gases are lost to the steam phase in particular carbon dioxide; as a result, the chemistry of the fluids changes an
The 2017–18 Ford Trophy was the 47th season of the official List A cricket tournament in New Zealand, the seventh in a sponsorship deal between New Zealand Cricket and Ford Motor Company. The competition ran from 3 December 2017 to 24 February 2018. Canterbury were the defending champions; the final round of fixtures were all abandoned due to rain. As a result, Central Districts topped the table and were joined in the final stage with Auckland, Northern Districts and Canterbury. After the preliminary final matches, Central Districts and Auckland had progressed to the tournament final. Auckland won the tournament. Teams qualified for the finals Series home at ESPN Cricinfo
Demigod is the seventh studio album by Polish extreme metal band Behemoth. The album was recorded during May and July in 2004 at the Hendrix Studios and was released on 11 October 2004. Daniel Bergstrand mixed the record at the Dug out Studios in Uppsala, Sweden during July and August in 2004; the record was mastered at the Cutting Room in Stockholm, Sweden in August, 2004. The track "XUL" included a guest guitar solo by Karl Sanders of Nile; the track "Before the Æons Came" is an adaptation of a poem by British poet Algernon Charles Swinburne. The track "Conquer All" was featured as DLC in the rhythm game Rock Band 2, has continued to be featured in subsequent games. Along with being Behemoth's breakthrough album, Demigod is now considered a landmark album within the Polish death metal scene, with Decibel Magazine notably including it in their Hall of Fame