Conglomerate (geology)

conglomerate is a coarse-grained clastic sedimentary rock that is composed of a substantial fraction of rounded to sub-angular gravel sized clasts for example granules pebbles cobbles and boulders larger than 2 millimeters in diameter conglomerates formed by the consolidation and lithification of gravel conglomerates typically contain finer grained sediment for example either sand silt clay or combination of them called matrix by geologists filling their interstices and are often cemented by calcium carbonate iron oxide silica or hardened clay the size and composition of the gravel size fraction of a conglomerate may or may not vary in composition sorting and size in some conglomerates the gravel size class' consists almost entirely of what work Lake lasts at the time of deposition conglomerates can be found in sedimentary rock sequences of all ages but probably make up less than 1% by weight of all sedimentary rocks in terms of origin and depositional mechanisms they are closely related to Sam stones and exhibit many of the same types of sedimentary structures for example tabular and trough cross bedding and graded bedding classification conglomerates may be named and classified by the amount and type of matrix present composition of gravel sized clasts they contain size range of gravel sized clasts present the classification method depends on the type and detail of research being conducted a sedimentary rock composed largely of gravel is first named according to the roundness of the gravel if the gravel clasts that comprise it is largely well rounded to sub-rounded it is a conglomerate if the gravel clasts that comprise it are largely angular it abrooke SIA such bricks years should called sedimentary bricks years to differentiated them from other types for example volcanic and fault of Brooks's sedimentary rocks that contain a mixture of rounded and angular gravel clasts are sometimes called proxy au conglomerate equals texture equals conglomerates are rarely composed entirely of grab sighs clasts typically the space between the gravel size clasts is filled by a mixture composed of varying amounts of silt sand and clay known as matrix if the individual gravel clasts in a conglomerate are separated from each other by a nut and currents of matrix such that they are not in contact with each other and float within the matrix it is called a para conglomerate para conglomerates are also often on stratified and can contain more matrix than gravel clasts if the gravel clasts of a conglomerate are in contact with each other it is called an ortho conglomerate unlike para conglomerates although conglomerates are typically cross bedded and often well cemented and lithified by either calcite hematite quartz or clay the differences between para conglomerates and ortho conglomerate's reflect differences in how they are deposited para conglomerates are commonly either glacial tools or debris flow deposits although conglomerates are typically associated with aqueous currents of some sort equals class composition equals conglomerates are also classified according to the composition of their clasts a conglomerate or any clastic sedimentary rock that consists of a single rock or mineral is known as either a mono micked monolithic Holika micked ohralik a mikta conglomerate if the conglomerate consists of two or more different types of rocks minerals or combination of both it is known as either a poly metal poly mikta conglomerate if a poly mikta conglomerate contains an assortment of the costs of meta stable and unstable rocks and minerals it called either a Petra Mick torpor traumatic conglomerate in addition conglomerates are classified by sources indicated by the lithology of the gravel sized clasts if these clasts consist of rocks and minerals that are significantly different in lithology from the enclosing matrix and thus older and arrived from outside the basin of deposition the conglomerate is known as an extreme formational conglomerate if these casts consist of rocks and minerals that are identical to all consistent with the lithology of the enclosing matrix and thus banette contemporaneous and arrived from within the basin of deposition the conglomerate is known as an entry formational conglomerate to recognized types of type of entry formational conglomerates are shale pebble and flat pebble conglomerates a shale pebble conglomerate is a conglomerate that is composed largely of classed surrounded mud ships and pebbles held together by clay minerals and created by erosion within environment such as within a river channel or along a lake margin flat pebble conglomerates are conglomerates that consist of relatively flat classed sublime mud created by either storms or tsunami a roading a shallow sea bottom or tidal current eroding tidal flats along a shoreline equals class size equals finally conglomerates are often differentiated and named according to the dominant class size comprising them in this classification a conglomerate composed largely of granule size clasts would be called a granule conglomerate a conglomerate composed largely of pebble sized clasts would be called a pebble conglomerate and a conglomerate composed largely of cobble sized clasts would be called a cobble conglomerate sedimentary environments conglomerates are deposited in a variety of sedimentary environments equals deep way to marine equals in turbidites the basal part of a bed is typically coarse-grained and sometimes conglomerate 'ok in this setting conglomerates are normally very well sorted well rounded and often with a strong a axis type implication of the costs equals shallow marine equals conglomerates are normally present at the base of sequences laid down during marine transgressions above an unconformity and are known as basal conglomerates they represent the position of the shoreline at a particular time under dark Ronis equals flew VL equals conglomerates deposited in fluvial environments are typically well rounded and well sorted clasts of this size are carried as bedload and only at times of high flow rate the maximum class size decreases as the clasts are transported further due to attrition so conglomerates are more characteristic of immature river systems in the sediments deposited by material conglomerates are generally confined to the basal part of a channel fill where they are known as pebble lags conglomerates deposited in a fluvial environment often have an a/b plane type imbrication equals alluvial equals alluvial deposits foreman areas of high relief and are typically coarse-grained at mountain front individual alluvial fans merge to form bread planes and these two environments are associated with the thickest deposits of conglomerates the bulk of conglomerates deposited in this setting a class supported with a strong a/b plane in brocation matrix supported conglomerates as a result of debris flow deposition are quite commonly associated with many alluvial fans when such conglomerates accumulate within an alluvial fan in rapidly eroding environments the resulting Rock unit is often called a fan glomer 8 equals glacial equals glaciers carry a lot of coarse-grained material and many glacial deposits a conglomerate ik delights the sediments deposited directly by a glacier are typically poorly sorted matrix supported conglomerates the matrix is generally fine-grained consisting of finely milled rock fragments water laid deposits associated with glaciers are often conglomerate ik forming structures such as eskers examples an example of conglomerate can be seen at Montserrat near Barcelona here erosion has created vertical channels that give the characteristic jagged shapes the mountain is named for the rock is strong enough to use as a building material as in the Santa Maria de Montserrat abbey another example the crust own conglomerate occurs in and near the town of Chris tonne at the foot of the Sangre de Cristo Range in Colorado San Luis Valley the crust own conglomerate consists of poorly sorted fan glomer rates that accumulated in prehistoric alluvial fans and related fluvial systems some of these rocks have hues of red and green conglomerate cliffs are found on the east coast of Scotland from abroad northwards along the coastlines of the former counties of Angus and Kincardine Escher do not our castle sits on a rugged promontory of conglomerate jutting into the North Sea just south of the town of Stonehaven conglomerate may also be seen in the domed hills of kata Tjuta in Australia's Northern Territory in the 19th century a thick layer of Pottsville conglomerate was recognized to underlie anthracite coal measures in Pennsylvania met a conglomerate metamorphic alteration transforms conglomerate intimate a conglomerate see also padding stone Jasper conglomerate references external links conglomerate at Koshien Dan Northern Ireland

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