The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period 145 million years ago to the beginning of the Paleogene Period 66 mya. It is the last period of the Mesozoic Era, the longest period of the Phanerozoic Eon; the Cretaceous Period is abbreviated K, for its German translation Kreide. The Cretaceous was a period with a warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas; these oceans and seas were populated with now-extinct marine reptiles and rudists, while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds, as well as flowering plants, appeared; the Cretaceous ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs and large marine reptiles died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary, a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras.
The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris Basin and named for the extensive beds of chalk, found in the upper Cretaceous of Western Europe. The name Cretaceous was derived from Latin creta; the Cretaceous is divided into Early and Late Cretaceous epochs, or Lower and Upper Cretaceous series. In older literature the Cretaceous is sometimes divided into three series: Neocomian and Senonian. A subdivision in eleven stages, all originating from European stratigraphy, is now used worldwide. In many parts of the world, alternative local subdivisions are still in use; as with other older geologic periods, the rock beds of the Cretaceous are well identified but the exact age of the system's base is uncertain by a few million years. No great extinction or burst of diversity separates the Cretaceous from the Jurassic. However, the top of the system is defined, being placed at an iridium-rich layer found worldwide, believed to be associated with the Chicxulub impact crater, with its boundaries circumscribing parts of the Yucatán Peninsula and into the Gulf of Mexico.
This layer has been dated at 66.043 Ma. A 140 Ma age for the Jurassic-Cretaceous boundary instead of the accepted 145 Ma was proposed in 2014 based on a stratigraphic study of Vaca Muerta Formation in Neuquén Basin, Argentina. Víctor Ramos, one of the authors of the study proposing the 140 Ma boundary age sees the study as a "first step" toward formally changing the age in the International Union of Geological Sciences. From youngest to oldest, the subdivisions of the Cretaceous period are: Late Cretaceous Maastrichtian – Campanian – Santonian – Coniacian – Turonian – Cenomanian – Early Cretaceous Albian – Aptian – Barremian – Hauterivian – Valanginian – Berriasian – The high sea level and warm climate of the Cretaceous meant large areas of the continents were covered by warm, shallow seas, providing habitat for many marine organisms; the Cretaceous was named for the extensive chalk deposits of this age in Europe, but in many parts of the world, the deposits from the Cretaceous are of marine limestone, a rock type, formed under warm, shallow marine circumstances.
Due to the high sea level, there was extensive space for such sedimentation. Because of the young age and great thickness of the system, Cretaceous rocks are evident in many areas worldwide. Chalk is a rock type characteristic for the Cretaceous, it consists of coccoliths, microscopically small calcite skeletons of coccolithophores, a type of algae that prospered in the Cretaceous seas. In northwestern Europe, chalk deposits from the Upper Cretaceous are characteristic for the Chalk Group, which forms the white cliffs of Dover on the south coast of England and similar cliffs on the French Normandian coast; the group is found in England, northern France, the low countries, northern Germany, Denmark and in the subsurface of the southern part of the North Sea. Chalk is not consolidated and the Chalk Group still consists of loose sediments in many places; the group has other limestones and arenites. Among the fossils it contains are sea urchins, belemnites and sea reptiles such as Mosasaurus. In southern Europe, the Cretaceous is a marine system consisting of competent limestone beds or incompetent marls.
Because the Alpine mountain chains did not yet exist in the Cretaceous, these deposits formed on the southern edge of the European continental shelf, at the margin of the Tethys Ocean. Stagnation of deep sea currents in middle Cretaceous times caused anoxic conditions in the sea water leaving the deposited organic matter undecomposed. Half the worlds petroleum reserves were laid down at this time in the anoxic conditions of what would become the Persian Gulf and the Gulf of Mexico. In many places around the world, dark anoxic shales were formed during this interval; these shales are an important source rock for oil and gas, for example in the subsurface of the North Sea. During th
Louth is a market town and civil parish in the East Lindsey district of Lincolnshire, England. Louth is the principal centre for a large rural area of eastern Lincolnshire. Visitor attractions include St. James' Church, Hubbard's Hills, the market, many independent retailers and Lincolnshire's last remaining cattle market. Louth is at the foot of the Lincolnshire Wolds where they meet the Lincolnshire Marsh and is known as the Capital of the Lincolnshire Wolds, it developed where the ancient trackway along the Wolds, known as the Barton Street, crossed the River Lud. The town is east of a gorge carved into the Wolds; this area was formed from a glacial overspill channel in the last glacial period. The River Lud meanders through the gorge before entering the town. Louth had a population of 15,930 as of 2009; the Greenwich Meridian passes through the town and is marked on Eastgate with plaques on the north and south sides of the street, just east of the junction with Northgate, although this location is known to be incorrect as the line passes through a point just west of Eastgate's junction with Church Street.
A three-mile £6.6 million A16 Louth Bypass opened in 1991. The former route through the town is now designated as the B1520. Three handaxes have been found on the wolds surrounding Louth, dating from between 424,000 and 191,000 years ago, indicating inhabitation in Paleolithic era. Bronze Age archeological finds include a'barbed and tanged' arrowhead found in the grounds of Monks' Dyke Tennyson College. St Helen's Spring, at the Gatherums, off Aswell Street, is dedicated to a popular medieval saint, the mother of Constantine the Great, the first Roman Emperor to become a Christian, but is thought to be a Christianised Romano-British site for veneration of the pagan water-goddess Alauna; the Anglo-Saxon pagan burial ground, northwest of Louth, dates from the fifth to sixth centuries, was first excavated in 1946. With an estimated 1200 urn burials it is one of the largest Anglo-Saxon cremation cemeteries in England.Æthelhard, a Bishop of Winchester, made Archbishop of Canterbury in 793, was an abbot of Louth in his early life.
Louth is listed in the 1086 Domesday Book as a town of 124 households. Louth Park Abbey was founded in 1139 by the Bishop Alexander of Lincoln as a daughter-house of the Cistercian Fountains Abbey in Yorkshire. Following its dissolution in 1536 it fell into ruin and, only earthworks survive, on private land, between Louth and Keddington. Monks' Dyke, now a ditch, was dug to supply the abbey with water from the springs of Ashwell and St. Helen's at Louth. In 1643, Sir Charles Bolles, a resident of Louth, raised a'hastily-got-up soldiery' for the Royalist cause in the English Civil War. Fighting took place in, around the town and, at one point, Bolles was forced to take refuge under the Ramsgate bridge. By the battle's end'Three strangers, being souldgeres, was slain at a skirmish at Lowth, was buryed'. Human remains, found during archaeological visits to Louth Park Abbey during the 1800s, in'a little space surrounded by a ditch', were believed to date from the Civil War as two cannonballs, from that era, were found with the bodies.
The Louth flood of 1920 occurred in the town on 29 May 1920. One woman climbed a chimney to survive, another was the only survivor from a row of twelve terrace houses, which were destroyed by the flood waters. Four stone plaques exist in the town to show. Other, less devastating floods occurred in July 1968 and on 25 June and 20 July in 2007. Margaret Wintringham succeeded her dead husband at the Louth by-election in September 1921, to become the Liberals' first female MP, Britain's third female MP. St Herefrith, or Herefrid, is Louth's ` forgotten saint', he was a bishop, who died around 873 killed by the Danes. An 11th-century text describes Herefrith as Bishop of Lincoln, but as the bishopric there dates to 1072, Lincoln more refers to Lindsey, the early name for Lincolnshire. Similar confusion exists in an inventory of Louth's St. James Church, written in 1486 and transcribed in 1512, where he is referred to as a Bishop of Auxerre, France. At some point, following his death, a shrine venerating him was established at Louth.
Æthelwold, the Bishop of Winchester from 963 to 984, was seeking relics for his newly rebuilt Thorney Abbey in Cambridgeshire and sent his monks to Louth to raid Herefrith's shrine. From an 11th-century account, Æthelwold had:...heard of the merits of the blessed Herefrid bishop of Lincoln resting in Louth a chief town of the same church. When all those dwelling there had been put to sleep by a cunning ruse, a trusty servant took him out of the ground, wrapped him in fine line cloth, with all his fellows rejoicing brought him to the monastery of Thorney and re-interred him. A church dedicated to St. Herefrith, at Louth, appears in accounts from the 13th to 15th centuries, one of his relics, an ivory comb, is recorded among the possessions of Louth's St. James Church in 1486. Suggestions that the shrine, church, of St. Herefrith, were earlier incarnations of St. James has'no supportive evidence' but St James' is the site of two earlier churches of which little is known. Louth railway station was a major intermediate station on the East Lincolnshire Railway which ran from Boston railway station to Grimsby Town railway station from 1848 and was served by rail motor services.
Louth was served by the Mablethorpe Loop Line as the terminus of the line which ran to nearby villages and towns of Mablethorpe, Sutton-on-Sea, Saltfleetby, Theddlethorpe and Willoughby. The station was the start and terminus on the Louth to Bardney Line which opened in 1876 but
The River Ancholme is a river in Lincolnshire, a tributary of the Humber. It rises at Ancholme Head, a spring just north of the village of Ingham and west of the Roman Road, Ermine Street, it flows east and north to Bishopbridge, where it is joined by the Rase. North of Bishopbridge it flows through the market town of Brigg before draining into the Humber at South Ferriby, it drains a significant part of northern Lincolnshire between the North Sea. The river has been used by humans since at least 800 BC, confirmed by the excavation of a planked boat at Brigg, patents covering improvements to the river are known from 1287 onwards. Major change occurred in 1635, when a new straight channel was constructed from Bishopbridge to Ferriby; the new channel carries most of the water and is known as the New River Ancholme, whereas the Old River Ancholme maintains its natural course, meandering from side to side. The old course is reduced to a drain, except around the town of Brigg where the two rivers create an island in the centre of Brigg known as'Island Carr'.
Further improvements were started by John Rennie in the early 1800s and completed by his son in the 1820s, with the reconstruction of Ferriby Sluice taking place around 1841. From that time onwards the river was reasonably profitable, although receipts were reduced when railways arrived in the area, trade picked up in the 1890s, was boosted by cargoes of sugar beet in the 1930s. All commercial carrying had ceased above Brigg by the 1970s, stopped altogether in the 1980s; the upper section was derelict by but was restored and dredged in 2004. The river is an important drainage channel for north Lincolnshire, but is used for leisure, with boating, rowing and fishing taking place. Responsibility for the river changed six times between 1930 and 1996, but it is now managed by the Environment Agency; the Ancholme Internal Drainage Board maintains twelve pumping stations on the banks of the river, which pump water from the surrounding low-lying land to prevent flooding. The river supplies large volumes of water to the Scunthorpe Steelworks, to Anglian Water, who use it to provide a public water supply to the South Humber bank industrial area.
In order to maintain this volume of abstraction during the summer months, other dry periods, water is transferred from Barlings Eau, near the River Witham, by the Trent Witham Ancholme transfer scheme, commissioned in 1974. Few of the bridges which cross the river form part of a public road, so they have not been replaced to cope with increased traffic. A number of them are listed structures; the river is home to two historic boats owned by the Humber Keel & Sloop Preservation Society. In its natural post-glacial state, the river's valley was flat-bottomed: it had formed the bed of the glacial Lake Ancholme, on an outwash delta, as the ice retreated, was fenny. There is evidence that boats have used the river from early times, for there have been three significant archaeological finds of ancient boats. Logboats have been found at Brigg and Appleby, a planked boat was found at Brigg in 1888. Professor McGrail conducted a re-excavation of the site in 1974, to discover the bottom of a flat-bottomed boat, made from oak planks, sewn together and caulked with moss.
The boat was thus similar in construction to the Ferriby Boats found on the northern shore of the Humber, but was some 500 years younger, being carbon-dated to around 800 BC. Further evidence of the local importance of the river in prehistory is evidenced by other finds or archaeology close to the river's course; as an example, in the parish of Bishop Norton, situated just over 1 km north of Bishopbridge. In this parish the Lincolnshire Historical Environment Record records just under 90 sites, from different historic periods; the majority of the prehistorical sites, including settlements, are close to the Ancholme. Most of these range from the Neolithic, through the Bronze Age to the Romano-British period; the oldest find in the parish was a Paleolithic handaxe discovered close to the site of the Harlam Hill Lock on a hummock of river gravels. This find dates anywhere from 500,000 BCE to 150,001 BCE; this axe, along with several Neolithic axes are now in Lincoln Museum. The course of the old river acts as a boundary for Bishop Norton and all the other parishes that abut it.
This being the eastern boundary. The fact that the majority of archaeology in the parish, as recorded in the HER that dates from after the construction of the Roman Road, tends to the western end of the parish close to the Roman road, that from earlier periods tends to be closer to the river is suggestive that the River was a primary communications route as well as the provider of physical and economic need, supplanted by the new road. Despite suffering from silting as a result of water from the Humber entering it, passing through land, waterlogged on both sides, the Ancholme offered a route into the communities of northern Lincolnshire. Cargo was carried on it from an early date: in 1287 a patent was granted to allow improvements to be made from Bishopbridge to Ferriby, so that boats could more carry grain and other commodities on the river "as they had done formerly". However, the major concern of the local landowners seems to have been that it should act as an effective drainage channel to prevent inundation of their lands, between 1289 and 1418 the river was mentioned in the Patent Rolls thirteen times.
The need to keep the channel scoured was always mentioned, but navigation was not. The river was
Parts of Holland
The Parts of Holland is a historical subdivision used in south-east Lincolnshire, England from 1889 to 1974. The name survives in the district of South Holland. Parts of Holland was one of the three medieval subdivisions or'Parts' of Lincolnshire which had long had separate county administrations. Under the Local Government Act 1888 it obtained a county council, which it retained until 1974. At that point the three county councils were abolished and Lincolnshire had a single county council for the first time. Before the changes of 1888, Holland had, since the tenth century, been divided into the three wapentakes of Elloe and Skirbeck. Under the Local Government Act 1894 it was divided into rural districts and urban districts, with the municipal borough of Boston remaining untouched; the rural districts were Boston, East Elloe and Spalding, whilst Holbeach, Long Sutton and Sutton Bridge became urban districts. In 1932, the Crowland RD was abolished and added to Spalding RD, all urban districts apart from Spalding were abolished and added to East Elloe Rural District.
The extent of Holland County Council was the same as that of the combined modern local government districts of Boston and South Holland. Holland was all close to sea level, achieving a maximum altitude of about five metres on artificially raised river banks, it therefore needed managed drainage to maintain the productive arable farmland which covered its entire extent. A significant part of its drainage for arable use had to await the introduction of steam pumping. Before the mid-19th century, it was a much more pastoral area, used for fattening livestock brought in from Scotland and northern England before it was driven to market in places like London. Many of the country roads are still called droves. Boston Crowland Donington Swineshead Holbeach Long Sutton SpaldingThe motto shown on the coat of arms, Labor Ipse Memores, is incorrect and should read Labor Ipse Merces. Examples may be seen in the window of the old hall at Boston Grammar School, on the wall of the dining room at Lincoln Hall, University of Nottingham.
There is a resemblance in landscape between the Parts of Holland and Holland, the region in the Netherlands, although their meanings are different. Holland in England means "land of the hill spurs", although hill spurs are hardly obvious, while the Dutch Holland is derived from the Old Dutch term holt-lant. Both Hollands have landscapes that are low lying and both are known for tulip growing. Map of Holland on Wikishire https://web.archive.org/web/20071001030631/http://www.visionofbritain.org.uk/relationships.jsp?u_id=10041806
Yorkshire, formally known as the County of York, is a historic county of Northern England and the largest in the United Kingdom. Due to its great size in comparison to other English counties, functions have been undertaken over time by its subdivisions, which have been subject to periodic reform. Throughout these changes, Yorkshire has continued to be recognised as a geographical territory and cultural region; the name is familiar and well understood across the United Kingdom and is in common use in the media and the military, features in the titles of current areas of civil administration such as North Yorkshire, South Yorkshire, West Yorkshire and East Riding of Yorkshire. Within the borders of the historic county of Yorkshire are vast stretches of unspoiled countryside; this can be found in the Yorkshire Dales and North York Moors and with the open aspect of some of the major cities. Yorkshire has been named "God's Own County" or "God's Own Country"; the emblem of Yorkshire is the White Rose of the English royal House of York, the most used flag representative of Yorkshire is the White Rose on a blue background, which after nearly fifty years of use, was recognised by the Flag Institute on 29 July 2008.
Yorkshire Day, held annually on 1 August, is a celebration of the general culture of Yorkshire, ranging from its history to its own dialect. Yorkshire is covered by different Government Office Regions. Most of the county falls within Yorkshire and the Humber while the extreme northern part of the county, such as Middlesbrough, Redcar and Startforth, falls within North East England. Small areas in the west of the county are covered by the North West England region. Yorkshire or the County of York was so named as it is the shire of York's Shire. "York" comes from the Viking name for Jórvík. "Shire" is from scir meaning care or official charge. The "shire" suffix is locally pronounced /-ʃə/ "shuh", or /-ʃiə/, a homophone of "sheer". Early inhabitants of Yorkshire were Celts, who formed two separate tribes, the Brigantes and the Parisi; the Brigantes controlled territory which became all of the North Riding of Yorkshire and the West Riding of Yorkshire. The tribe controlled most of Northern England and more territory than any other Celtic tribe in England.
That they had the Yorkshire area as their heartland is evident in that Isurium Brigantum was the capital town of their civitas under Roman rule. Six of the nine Brigantian poleis described by Claudius Ptolemaeus in the Geographia fall within the historic county; the Parisi, who controlled the area that would become the East Riding of Yorkshire, might have been related to the Parisii of Lutetia Parisiorum, Gaul. Their capital was at Petuaria, close to the Humber Estuary. Although the Roman conquest of Britain began in 43 AD, the Brigantes remained in control of their kingdom as a client state of Rome for an extended period, reigned over by the Brigantian monarchs Cartimandua and her husband Venutius; this situation suited both the Romans and the Brigantes, who were known as the most militant tribe in Britain. Queen Cartimandua left her husband Venutius for his armour bearer, setting off a chain of events which changed control of the region. Cartimandua, due to her good relationship with the Romans, was able to keep control of the kingdom.
At the second attempt, Venutius seized the kingdom, but the Romans, under general Petillius Cerialis, conquered the Brigantes in 71 AD. The fortified city of Eboracum was named as capital of Britannia Inferior and joint capital of all Roman Britain; the emperor Septimius Severus ruled the Roman Empire from Eboracum for the two years before his death. Another emperor, Constantius Chlorus, died in Eboracum during a visit in 306 AD; this saw his son Constantine the Great, who became renowned for his contributions to Christianity, proclaimed emperor in the city. In the early 5th century, the Roman rule ceased with the withdrawal of the last active Roman troops. By this stage, the Western Empire was in intermittent decline. After the Romans left, small Celtic kingdoms arose in the region, including the Kingdom of Ebrauc around York and the Kingdom of Elmet to the west. Elmet remained independent from the Germanic Northumbrian Angles until some time in the early 7th century, when King Edwin of Northumbria expelled its last king and annexed the region.
At its greatest extent, Northumbria stretched from the Irish Sea to the North Sea and from Edinburgh down to Hallamshire in the south. Scandinavian York or Danish/Norwegian York is a term used by historians for the south of Northumbria during the period of the late 9th century and first half of the 10th century, when it was dominated by Norse warrior-kings. Norse monarchy controlled varying amounts of Northumbria from 875 to 954, however the area was invaded and conquered for short periods by England between 927 and 954 before being annexed into England in 954, it was associated with the much longer-lived Kingdom of Dublin throughout this period. An army of Danish Vikings, the Great Heathen Army as its enemies referred to it, invaded Northumbrian territory in 866 AD; the Danes conquered and assumed what is now York and renamed it Jórvík, making it the capital city of a new Danish kingdom under the same name. The area which this kingdom covered included most of Southern Northumbria equivalent to the borders of Yorkshire extending further West.
The Danes went on to conque
Goulceby with Asterby
Goulceby with Asterby are villages and civil parishes in the East Lindsey district of Lincolnshire, England. They are situated 7 miles south-west from the market town of Louth, lie in the Lincolnshire Wolds, an Area of Outstanding Natural Beauty. Goulceby village is conjoined with the hamlet of Asterby, both marked on local road signs as one settlement, Goulceby with Asterby, although the two form separate civil parishes. Goulceby was the birthplace of William Marwood, who invented the "long drop" system of execution; until 2012 local democracy took the form of the'Asterby, Goulceby & Ranby Grouped Parish Council', but at the request of the people of Ranby, it was split to form the'Asterby & Goulceby Parish Council' and the'Ranby Parish Meeting'. The Ecclesiastical parishes are still separate, as Asterby and Ranby. All three are part of the Asterby group of the Deanery of Horncastle. Media related to Goulceby with Asterby at Wikimedia Commons
Sandstone is a clastic sedimentary rock composed of sand-sized mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds form visible cliffs and other topographic features, certain colors of sandstone have been identified with certain regions. Rock formations that are composed of sandstone allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be changed into quartzite through metamorphism related to tectonic compression within orogenic belts.
Sandstones are clastic in origin. They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals; the cements binding these grains together are calcite and silica. Grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are called argillaceous sediments; the formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Sedimentation occurs by the sand settling out from suspension. Once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains; the most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried.
Colors will be tan or yellow. A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe and Mongolia; the regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction. The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings: Terrestrial environmentsRivers Alluvial fans Glacial outwash Lakes Deserts Marine environmentsDeltas Beach and shoreface sands Tidal flats Offshore bars and sand waves Storm deposits Turbidites Framework grains are sand-sized detrital fragments that make up the bulk of a sandstone.
These grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks. These physical properties allow the quartz grains to survive multiple recycling events, while allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and from older sandstones that have been recycled. Feldspathic framework grains are the second most abundant mineral in sandstones. Feldspar can be divided into two smaller subdivisions: plagioclase feldspars; the different types of feldspar can be distinguished under a petrographic microscope. Below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution. Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.
Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. Common accessory minerals include micas, olivine and corundum. Many of these accessory grains are more dense than the silicates that