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45-907: The Loudoun Valley is a small, but historically significant valley in the Blue Ridge Mountains located in Loudoun County in Northern Virginia in the United States . The lush and fertile valley lies between Catoctin Mountain and the Bull Run Mountains to the east and the Blue Ridge Mountains to the west. To the north it is bound by the Potomac River and to the south by the Broken Hills of Fauquier County . The small portion of

90-414: A broader floodplain may result. Deposition dominates over erosion. A typical river basin or drainage basin will incorporate each of these different types of valleys. Some sections of a stream or river valleys may have vertically incised their course to such an extent that the valley they occupy is best described as a gorge , ravine , or canyon . Rapid down-cutting may result from localized uplift of

135-527: A cirque glacier. During glacial periods, for example, the Pleistocene ice ages, it is in these locations that glaciers initially form and then, as the ice age proceeds, extend downhill through valleys that have previously been shaped by water rather than ice. Abrasion by rock material embedded within the moving glacial ice causes the widening and deepening of the valley to produce the characteristic U or trough shape with relatively steep, even vertical sides and

180-439: A main occupation for several generations until the early 1990s when urban growth began encroaching from the east. Though farming has lost its prominence in the valley, it maintains a strong presence. Loudoun County ranks twentieth in overall agriculture production in the state. Corn, wheat, and beans remain staple crops, while berry production has increased dramatically (ranked first in the state). Christmas tree farming (third in

225-517: A major feature of the Loudoun landscape. Germans settled in the northern end of the Loudoun Valley, especially in the area around Lovettsville , leaving a number of log structures as their architectural legacy. Unlike the settlers to the east and south, neither of these groups practiced slavery . In the southern portion of the valley, centered on Middleburg , settlers of English descent moving west from

270-584: A narrow valley with steep sides. Gill is used to describe a ravine containing a mountain stream in Cumbria and the Pennines . The term combe (also encountered as coombe ) is widespread in southern England and describes a short valley set into a hillside. Other terms for small valleys such as hope, dean, slade, slack and bottom are commonly encountered in place-names in various parts of England but are no longer in general use as synonyms for valley . The term vale

315-432: A relatively flat bottom. Interlocking spurs associated with the development of river valleys are preferentially eroded to produce truncated spurs , typical of glaciated mountain landscapes. The upper end of the trough below the ice-contributing cirques may be a trough-end . Valley steps (or 'rock steps') can result from differing erosion rates due to both the nature of the bedrock (hardness and jointing for example) and

360-465: A slower rate than that of the main valley floor; thus the difference in the two valleys' depth increases over time. The tributary valley, composed of more resistant rock, then hangs over the main valley. Trough-shaped valleys also form in regions of heavy topographic denudation . By contrast with glacial U-shaped valleys, there is less downward and sideways erosion. The severe downslope denudation results in gently sloping valley sides; their transition to

405-427: A valley between its sides is referred to as the valley floor. The valley floor is typically formed by river sediments and may have fluvial terraces . The development of a river valley is affected by the character of the bedrock over which the river or stream flows, the elevational difference between its top and bottom, and indeed the climate. Typically the flow will increase downstream and the gradient will decrease. In

450-500: A variety of transitional forms between V-, U- and plain valleys can form. The floor or bottom of these valleys can be broad or narrow, but all valleys have a shoulder. The broader a mountain valley, the lower its shoulders are located in most cases. An important exception is canyons where the shoulder almost is near the top of the valley's slope. In the Alps – e.g. the Tyrolean Inn valley –

495-670: A watercourse only rarely. In areas of limestone bedrock , dry valleys may also result from drainage now taking place underground rather than at the surface. Rift valleys arise principally from earth movements , rather than erosion. Many different types of valleys are described by geographers, using terms that may be global in use or else applied only locally. Valleys may arise through several different processes. Most commonly, they arise from erosion over long periods by moving water and are known as river valleys. Typically small valleys containing streams feed into larger valleys which in turn feed into larger valleys again, eventually reaching

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540-405: Is a tributary valley that is higher than the main valley. They are most commonly associated with U-shaped valleys, where a tributary glacier flows into a glacier of larger volume. The main glacier erodes a deep U-shaped valley with nearly vertical sides, while the tributary glacier, with a smaller volume of ice, makes a shallower U-shaped valley. Since the surfaces of the glaciers were originally at

585-501: Is only 50 meters (160 ft) deep while the main fjord is around 1,300 meters (4,300 ft) at the same point. Glaciated terrain is not the only site of hanging streams and valleys. Hanging valleys are also simply the product of varying rates of erosion of the main valley and the tributary valleys. The varying rates of erosion are associated with the composition of the adjacent rocks in the different valley locations. The tributary valleys are eroded and deepened by glaciers or erosion at

630-481: Is the word cwm borrowed from Welsh . The word dale occurs widely in place names in the north of England and, to a lesser extent, in southern Scotland. As a generic name for a type of valley, the term typically refers to a wide valley, though there are many much smaller stream valleys within the Yorkshire Dales which are named "(specific name) Dale". Clough is a word in common use in northern England for

675-614: Is used in England and Wales to describe a wide river valley, usually with a particularly wide flood plain or flat valley bottom. In Southern England, vales commonly occur between the outcrops of different relatively erosion-resistant rock formations, where less resistant rock, often claystone has been eroded. An example is the Vale of White Horse in Oxfordshire. Some of the first human complex societies originated in river valleys, such as that of

720-674: The Catoctin Valley , is associated with it. Major watercourses include Goose Creek , Catoctin Creek , Panther Skin Run, and the Little River . The three major highways across the valley are U.S. Route 50 , which runs from Aldie on the east to Ashby Gap on the west; Route 7 , which runs from Clarke's Gap west of Leesburg to Snickers Gap west of Bluemont ; and Route 9 , which diverges from Route 7 at Clarke's Gap and runs west to Keyes Gap on

765-506: The Latin terms for 'valley, 'gorge' and 'ditch' respectively. The German term ' rille ' or Latin term 'rima' (signifying 'cleft') is used for certain other elongate depressions on the Moon. See also: Loudoun Rangers The Loudoun Rangers , also known as Mean's Rangers for their commander, Samuel C. Means , was a partisan cavalry unit raised in Loudoun County, Virginia , that fought for

810-496: The Nile , Tigris-Euphrates , Indus , Ganges , Yangtze , Yellow River , Mississippi , and arguably the Amazon . In prehistory , the rivers were used as a source of fresh water and food (fish and game), as well as a place to wash and a sewer. The proximity of water moderated temperature extremes and provided a source for irrigation , stimulating the development of agriculture . Most of

855-568: The Tidewater region imported slave-based plantation-style agriculture. During the antebellum period, the area became a leading center of agriculture production, particularly of wheat, oats, rye, and corn. During the Civil War , the Loudoun Valley saw considerable fighting. Owing the Valley's divided loyalties, one-time neighbors took up arms against one another in bitter partisan fighting. Unionists from

900-672: The Union during the American Civil War . The Rangers have the distinction of being the only unit raised in present-day Virginia to serve in the Union Army . The Loudoun Rangers were formed in the spring of 1862, when the Union Army first occupied Loudoun County as part of its campaign in the Shenandoah Valley. Returning with the army was local unionist Samuel Means, who had been run out of

945-462: The West Virginia border. The terrain is rolling, with numerous ridges and hills; the elevation here ranges between 350 and 730 feet (110 and 220 m) above sea level. The soil is formed from gneiss , clay / slate , hornblende , greenstone , and quartz particles, a fertile and durable soil, containing alumina , silex , potash , lime , and other natural fertilizing minerals. Following

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990-664: The first civilizations developed from these river valley communities. Siting of settlements within valleys is influenced by many factors, including the need to avoid flooding and the location of river crossing points. Numerous elongate depressions have been identified on the surface of Mars , Venus , the Moon , and other planets and their satellites and are known as valles (singular: 'vallis'). Deeper valleys with steeper sides (akin to canyons) on certain of these bodies are known as chasmata (singular: 'chasma'). Long narrow depressions are referred to as fossae (singular: 'fossa'). These are

1035-583: The 1722 Treaty of Albany, which expelled Indigenous nations west of the Blue Ridge Mountains, white settlers began to occupy the Loudoun Valley. Many of the early white residents were immigrants from southern Pennsylvania — Quakers , Scotch-Irish , and Germans interested in starting small farms. The Quakers had significant influence in the central Loudoun Valley, settling in and around such communities as Waterford , Hillsboro , Goose Creek (now Lincoln ), and Union (now Unison ). Their stone buildings are

1080-513: The Scandinavian ice sheet during the various ice ages advanced slightly uphill against the lie of the land. As a result, its meltwaters flowed parallel to the ice margin to reach the North Sea basin, forming huge, flat valleys known as Urstromtäler . Unlike the other forms of glacial valleys, these were formed by glacial meltwaters. Depending on the topography , the rock types , and the climate ,

1125-713: The Union columns during the often overlooked Battle of Unison . During the Gettysburg Campaign , a series of cavalry clashes between J.E.B. Stuart and Alfred Pleasonton occurred in the valley at Aldie , Middleburg , Goose Creek , and Upperville . Stuart successfully kept the Federal forces from entering the adjacent Shenandoah Valley and discovering Robert E. Lee 's main army. In 1864, as General Jubal Early withdrew from Washington , Union forces attacked his supply wagons at Heaton's Crossroads at present-day Purcellville . In

1170-504: The actual valley bottom is unclear. Trough-shaped valleys occur mainly in periglacial regions and in tropical regions of variable wetness. Both climates are dominated by heavy denudation. Box valleys have wide, relatively level floors and steep sides. They are common in periglacial areas and occur in mid-latitudes, but also occur in tropical and arid regions. Rift valleys, such as the Albertine Rift and Gregory Rift are formed by

1215-467: The county the previous year by local Confederates. Secretary of War Edwin M. Stanton issued Means orders to raise a company of men to serve as an independent command, of which he would be captain, for special service in Loudoun and along the Virginia-Maryland border. Recruiting operations were established in the northern Loudoun Valley , an area of strong unionist sentiment, eventually leading to

1260-533: The early winter of 1864, General Phillip Sheridan had the Loudoun Valley put to the torch during The Burning Raid in response to actions of Confederate partisans John Mosby who used the Loudoun Valley as his base of operations. Following the war, the Loudoun Valley was slow to recover from the devastation of the Burning Raid, but soon the region became a major source of agricultural products again, particularly notable for its numerous dairy farms. Farming remained

1305-599: The expansion of the Earth 's crust due to tectonic activity beneath the Earth's surface. There are many terms used for different sorts of valleys. They include: Similar geographical features such as gullies , chines , and kloofs , are not usually referred to as valleys. The terms corrie , glen , and strath are all Anglicisations of Gaelic terms and are commonly encountered in place-names in Scotland and other areas where Gaelic

1350-454: The first time. Major engagements between the regular armies also occurred in the Valley, particularly in 1862 and 1863. In November 1862, following the Battle of Antietam , Union Gen. George McClellan marched his army through the Valley in slow pursuit of the retreating Army of Northern Virginia . Confederate cavalry under Maj. Gen. J.E.B. Stuart fought a delaying action against the vanguard of

1395-443: The flow slower and both erosion and deposition may take place. More lateral erosion takes place in the middle section of a river's course, as strong currents on the outside of its curve erode the bank. Conversely, deposition may take place on the inside of curves where the current is much slacker, the process leading to the river assuming a meandering character. In the lower valley, gradients are lowest, meanders may be much broader and

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1440-581: The formation of 2 companies. For the first two years of service the Loudoun Rangers served as partisans, often in conjunction with Cole's Maryland Cavalry (1st Potomac Home Brigade) fighting their confederate counterparts, such as White's Comanches , Mosby's Rangers and John Mobberly 's renegade band in and around Loudoun. In 1864 the Rangers were absorbed into regular service, leading to Means' departure. Daniel Keyes subsequently took his place as leader of

1485-427: The land surface or rejuvenation of the watercourse as a result for example of a reduction in the base level to which the river is eroded, e.g. lowered global sea level during an ice age . Such rejuvenation may also result in the production of river terraces . There are various forms of valleys associated with glaciation. True glacial valleys are those that have been cut by a glacier which may or may not still occupy

1530-466: The northern portion of the Valley formed the partisan Loudoun Rangers , while southern sympathizers in the southern portion joined a number of partisan Confederate units including White's Rebels and Mosby's Rangers . These units frequently engaged one another in the Valley throughout the duration of the war, most noticeably at the Fight at Waterford in 1862 when White's Rebels engaged the Loudoun Rangers for

1575-463: The ocean or perhaps an internal drainage basin . In polar areas and at high altitudes, valleys may be eroded by glaciers ; these typically have a U-shaped profile in cross-section, in contrast to river valleys, which tend to have a V-shaped profile. Other valleys may arise principally through tectonic processes such as rifting . All three processes can contribute to the development of a valley over geological time. The flat (or relatively flat) portion of

1620-536: The outfit. During the final years of the war the Rangers were attached to the Union army in the Shenandoah Valley and took part in the Valley Campaigns of 1864 under General Phillip Sheridan . As the war in the valley came to an end, the Rangers returned to their partisan role and were eventually effectively broken up in April 1865 when a detachment of Mosby's Rangers raided their camp at Castleman's Ferry and captured

1665-436: The power of the moving ice. In places, a rock basin may be excavated which may later be filled with water to form a ribbon lake or else by sediments. Such features are found in coastal areas as fjords . The shape of the valley which results from all of these influences may only become visible upon the recession of the glacier that forms it. A river or stream may remain in the valley; if it is smaller than one would expect given

1710-446: The same elevation , the shallower valley appears to be 'hanging' above the main valley. Often, waterfalls form at or near the outlet of the upper valley. Hanging valleys also occur in fjord systems underwater. The branches of Sognefjord are much shallower than the main fjord. The mouth of Fjærlandsfjord is about 400 meters (1,300 ft) deep while the main fjord nearby is 1,200 meters (3,900 ft) deep. The mouth of Ikjefjord

1755-543: The shoulders are quite low (100–200 meters above the bottom). Many villages are located here (esp. on the sunny side) because the climate is very mild: even in winter when the valley's floor is filled with fog, these villages are in sunshine . In some stress-tectonic regions of the Rocky Mountains or the Alps (e.g. Salzburg ), the side valleys are parallel to each other, and are hanging . Smaller streams flow into rivers as deep canyons or waterfalls . A hanging valley

1800-849: The size of its valley, it can be considered an example of a misfit stream . Other interesting glacially carved valleys include: A tunnel valley is a large, long, U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. Such valleys can be up to 100 km (62 mi) long, 4 km (2.5 mi) wide, and 400 m (1,300 ft) deep (its depth may vary along its length). Tunnel valleys were formed by subglacial water erosion . They once served as subglacial drainage pathways carrying large volumes of meltwater. Their cross-sections exhibit steep-sided flanks similar to fjord walls, and their flat bottoms are typical of subglacial glacial erosion. In northern Central Europe,

1845-519: The state) and livestock (eleventh in state for sheep and lamb, fourteenth in state for cattle) are also major agricultural ventures. In the last decade the emergence of vineyards and wineries in the valley has led to it being a top producer of wine in the state. Valley At lower latitudes and altitudes, these glacially formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry

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1890-407: The upper valley, the stream will most effectively erode its bed through corrasion to produce a steep-sided V-shaped valley. The presence of more resistant rock bands, of geological faults , fractures , and folds may determine the course of the stream and result in a twisting course with interlocking spurs . In the middle valley, as numerous streams have coalesced, the valley is typically wider,

1935-407: The valley at the present day. Such valleys may also be known as glacial troughs. They typically have a U-shaped cross-section and are characteristic landforms of mountain areas where glaciation has occurred or continues to take place. The uppermost part of a glacial valley frequently consists of one or more 'armchair-shaped' hollows, or ' cirques ', excavated by the rotational movement downslope of

1980-587: The valley residing in Fauquier County is known as Upper Fauquier. The valley varies between 8 miles (13 km) and 12 miles (19 km) in width and is approximately 34 miles (55 km) long. The northern section of the valley is bisected by Short Hill Mountain . The area west of the Short Hill is known as Between the Hills and is distinct from the Loudoun Valley, while the area to the east, sometimes referred to as

2025-414: Was once widespread. Strath signifies a wide valley between hills, the floor of which is either level or slopes gently. A glen is a river valley which is steeper and narrower than a strath. A corrie is a basin-shaped hollow in a mountain. Each of these terms also occurs in parts of the world formerly colonized by Britain . Corrie is used more widely by geographers as a synonym for (glacial) cirque , as

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